In this excerpt from "The Carbon Wave" (MIT Press, 2026), author Leah Stokes, an associate professor of environmental politics at the University of California, Santa Barbara, looks at a hopeful moment in U.S. politics when climate change took center stage: when Rep. Alexandria Ocasio-Cortez and Sen. Ed Markey ramped up calls for a "Green New Deal."

In September 2017, a still­-unknown Alexandria Ocasio-­Cortez watched as Hurricane Maria devastated Puerto Rico. Electricity went down for months. Like thousands of Puerto Ricans, her grandfather died in the storm's aftermath. She could see how climate change was hitting her community harder than others.

And it wasn't just Ocasio-­Cortez's community: the year before, she'd traveled to Standing Rock, North Dakota, to see firsthand how the fossil fuel industry was harming Indigenous people. It was mere weeks after the 2016 election, and the resistance to Trump had found its center in a makeshift camp along the Missouri River. People had united to oppose an oil pipeline.

Serendipitously, the day after Ocasio-­Cortez left the protest, a progressive organization reached out to ask her to run for Congress. Moved by the activists at Standing Rock, she said yes. In 2018, she ran a long-­shot primary campaign in a Bronx district occupied by a ten-­term congressman in House leadership. Her platform included an idea that some had bandied about before, but no one had developed in earnest: a Green New Deal. As she told journalists that summer, "The Green New Deal we are proposing will be similar in scale to the mobilization efforts seen in World War II or the Marshall Plan. We must again invest in the development, manufacturing, deployment, and distribution of energy, but this time green energy." In June, she won the primary. Her election signaled the beginning of a broader shift: climate change was back on the political agenda.

That fall, the world's leading climate science organization, the Intergovernmental Panel on Climate Change —­ often called the IPCC —­ released a short report concluding that limiting warming to 1.5°C would require emissions to fall by almost half by 2030. The news ricocheted around the world, with headlines like "We Have 12 Years to Limit Climate Catastrophe." In my own neighborhood, someone printed a copy and stuck it in the free lending library, labeling it "important reading." The report changed how many people thought about the problem: it wasn't something we could deal with in 50 years; it was something we had to deal with today.

In the November 2018 midterm elections, two years into the first Trump administration, Democrats won big, paving the way for Nancy Pelosi to return as Speaker of the House after eight years as the minority leader. Days later, a group of young activists from the Sunrise Movement staged a sit-in at her office. Their bright yellow and­ black signs read "We have 12 years. What’s your plan?" referencing that scientific report.

Newly elected Representative Ocasio-­Cortez joined the action that day. She told the organizers they needed a clear ask and encouraged them to call for a Green New Deal. The idea broke through, sparking widespread coverage across the country. It was a new, hopeful vision for climate policy. These young people were not just talking about the climate disasters we needed to avoid —­ they were explaining how investments in clean energy could create good jobs. They were showing us the better world we could build together. If we only tried.

I watched these developments unfold in DC from my office by the Pacific Ocean and wanted to be a part of it. I wouldn't have to wait long. The Green New Deal held a force like gravity, pulling people into its orbit. By chance, I met some of the people tied to Ocasio-­Cortez at a conference and was invited to an early gathering to develop the idea into more detailed policy. By then, she'd released a framework for the plan with Senator Ed Markey of Massachusetts.

The meeting was held in March 2019, at a hip hotel in DC's Adams Morgan neighborhood, miles away from the Capitol. A wide swath of people were invited: youth activists, environmental justice leaders, political organizers, think tank wonks, and a few academics like me. It was a contentious meeting that opened with a protest, revealing fissures in the movement that would eventually grow into large cracks. Some people believed that frontline communities facing the greatest pollution burdens were not being adequately consulted or invited to participate in the event. At the time, I didn't understand these dynamics between the climate and environmental justice movements. I was just a political science professor trying to understand how I could make my work more practical and help get a climate law passed if we got the chance.

It was at that event that I met Varshini Prakash, the executive director of the Sunrise Movement. I’d seen her photo many times, standing in the middle of Pelosi's office with her dark red jacket over a black­ and yellow T-­shirt, surrounded by young people sitting on the floor. Four months had passed since the sit-­in, and Varshini had ricocheted to the center of the climate movement. But she was also a recent college grad in her mid-­twenties, feeling a heavy burden from the climate crisis and the work involved in fighting it. At one point during the meeting, she spoke frankly about the stress that was on her and other young activists and cried. I found her vulnerability moving.

The fact was, Varshini had already changed history. She'd given me, and millions of others, a sense of hope and possibility. It was her actions, alongside all the other organizers in the Sunrise Movement, that brought us together in that first DC convening, and in countless other meetings to come. She inspired me to believe that I could do something bigger if I tried.

Too often, the way we think about cause and effect is simplistic. We're fed a linear model that favors the immediate. One person is responsible for their own carbon footprint. One person only has one vote. One person can only do so much. From this perspective, standing against more than a century of fossil fuels running through the heart of our society, it can feel like there's nothing we could do to shake the system loose. We're too small. Mere drops. But drops in the ocean can make waves.

Excerpted from The Carbon Wave: A Story of Democracy, Parenthood, and the Race to Protect Our Planet by Leah C. Stokes. Reprinted with permission from The MIT Press. Copyright 2026.

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In the event of a global catastrophe, such as a nuclear war, an enormous volcanic eruption or large asteroid strike, the best place to be is Australia, according to a new study.

Researchers looked at the places that were most resilient to global catastrophic risks, which are events that would kill more than 10% of the global population over several months or years.

"These kinds of catastrophes are under-researched" because they are not very likely, study first author Florian Ulrich Jehn, a researcher at FernUniversität in Hagen, Germany, told Live Science. "That makes them easy to ignore."

But they are still possible — and no country would be unaffected if they occurred, he said. And some places are more vulnerable than others.

In the new study, published Aug. 23 in the journal Global Challenges, researchers analyzed studies across a variety of disciplines such as food security, biological weapons, and volcanism, to identify potential global catastrophic risks and the factors that helped communities to endure them in the past or on a smaller scale. They also brought in subject experts to add discipline-specific papers to their database.

The team identified three broad types of risk: events that would block out sunlight, such as nuclear war or a huge volcano explosion); events that destroy global infrastructure, such as a geomagnetic storm or massive cyber attack; and biological hazards, such as natural or human-caused infectious diseases that would kill much of the population.

These events, the authors wrote, would have significant and long-lasting global consequences. Many would result in global famine from crops failing and trade networks falling apart. "The food system is often the thing that gets you," Jehn said.

A trade-off of risks

The team identified characteristics that made countries more resilient to catastrophe and better able to feed their inhabitants. And while "no single place on Earth" would be resilient against all catastrophic risks, the authors wrote, some would fare better than others.

The team found that wealthier countries and regions with a strong industrial base that are not highly reliant on global trade are better able to weather global disasters.

With a strong industrial base, countries are able to manufacture goods that they cannot import, making them more resilient.

Geography also plays a role. Large islands have an advantage over continents because they can easily isolate, but they also need to have an economy that can at least partially support itself, the researchers said. If an island is highly reliant on international trade, like Japan, it will struggle if global trade networks are disrupted, the study found.

Certain countries and regions are less resilient in the face of some types of catastrophes, even if they are wealthy. For example, countries with nuclear capabilities, such as the U.S., the U.K., France, Israel, Russia, Pakistan, and India, are more at risk of being involved in nuclear war. This makes the Northern Hemisphere, where NATO countries are situated, more vulnerable to nuclear attack than places in the Southern Hemisphere.

There are also fewer volcanoes in the southern half of the globe, while the Southern Hemisphere has more ocean to act as a climate buffer, making countries there more resilient to a huge volcanic eruption, the study found.

Global resilience

There are some factors that make all countries better able to endure disasters in general, such as democratic processes and equality, Jehn said.

"When these catastrophes happen, you have to make the right decisions, and this depends on whether your country has functional governance," Jehn said. "Inequality makes governance worse, because it leads to things like elite rivalries, or less state capacity."

Australia came out as the best location to weather a catastrophic event that decimated global populations. It is in the Southern Hemisphere, so far away from the most likely location of a nuclear conflict (although the authors warn that it is allied with the U.S., which might increase its risk exposure). It is a major food producer, with diverse climatic zones, and has significant energy infrastructure.

Next best spots are Argentina, Brazil and New Zealand. New Zealand ranks lower than Australia because it has active volcanoes, a small industrial base, and is surrounded by water and vulnerable to tsunamis. Meanwhile, Brazil and Argentina have high levels of inequality and historical political instability, the authors wrote.

They also note that Iceland was a contender for a safe refuge, but its location in the far north makes it vulnerable to temperature shocks if a major incident were to block out sunshine.

The U.S. is not particularly well-placed to weather a global catastrophe, the study found. The country is exposed to the threat of geomagnetic storms because of its location and to nuclear war. The authors also pointed to the country’s poor COVID-19 outcomes, which appeared to be due to "a lack of political will and poor social cohesion."

David Denkenberger, director at Alliance to Feed the Earth in Disasters (ALLFED) and a researcher at the University of Canterbury in New Zealand, told Live Science that the new study aids our understanding of future risks by considering a wider range of catastrophes.

"No country is resilient to every catastrophe, and this is an important central finding," he said. "A useful next step would be to quantify the relative likelihood and severity of different catastrophes, and the importance of different resilience factors, because these factors can involve significant trade-offs," said Denkenberger, who has previously collaborated with Jehn but is not an author on the paper.

How to be more resilient

Even though these global catastrophes are unlikely, it is important to include them on national risk registers and have international trade agreements in place in case they come to pass, Jehn said. "When global catastrophes happen, then you would likely have to restructure the food system — where it is produced, where it is traded," he said. "The chance to find a good compromise after the catastrophe has happened seems slim."

Denkenberger echoed his comments. The study, he said, "makes it clear that regional resilience to global catastrophic risk requires investment in practical preparedness, including food-system resilience, critical infrastructure, coordinated trade and governance."

Two distinct climate regimes that could trigger runaway methane emissions are emerging in Siberia due to Arctic warming, new research suggests.

While western Siberia is becoming wetter in response to rising heat and moisture transported from the North Atlantic Ocean, eastern Siberia is getting drier and more prone to wildfires, a study published Aug. 6 in the journal Science finds. The Yenisei River (also spelled Yenisey) in central Russia delineates the separate environmental states — referred to as regimes because they describe specific types of climates — on each side of the basin, the study authors said.

Between 2010 and 2023, methane emissions from Siberia rose by 5% per year, with western Siberia releasing methane mainly via microbial activity in thawing soils and eastern Siberia discharging the powerful greenhouse gas through biomass burning, the results showed.

"Given the observed increases in permafrost thaw, wetland activity, and wildfire occurrence, an increase in methane emissions was expected," study co-author Paul Palmer, a professor in the School of Geosciences at the University of Edinburgh, told Live Science in an email. "What is surprising is how large and sustained the increase appears to be."

Annual methane emissions grew by about 13.2 million tons (12 million metric tons) over the study period, almost mirroring the rate of increase in methane emissions from wetlands worldwide. Although Siberia currently makes up only about 5% of global methane emissions, the region is becoming one of the fastest-growing natural methane sources on the planet, Palmer said.

In their study, Palmer and his colleagues integrated satellite observations with near-surface measurements to map methane emissions from Siberia over time. Instead of adding up individual methane sources on the ground, the researchers used a modeling method known as a methane flux inversion system, which helped them limit the uncertainty in their estimates to roughly 10%.

Siberia is vast, remote, sparsely instrumented and currently inaccessible for many scientists due to the Russia-Ukraine war, making it hard to monitor methane consistently by any means other than satellites. Although satellites rely on sunlight, of which Siberia gets very little in the winter, most methane emissions are thought to occur in the spring and summer, when Siberia gets more sunlight, Palmer said.

The results of the study show that Arctic warming amplifies methane emissions via distinct pathways in western and eastern Siberia because the regions are influenced by different climate patterns. The researchers also used climate models to predict future methane emissions from Siberia and found that additional warming could unleash millions of tons of greenhouse gases stored in forests and permafrost, which would further accelerate the warming trend.

In western Siberia, methane is released mainly from permafrost, or ground that has stayed frozen for at least two consecutive years. Siberia holds 46% of the Northern Hemisphere's permafrost, and this icy sediment traps vast amounts of carbon that have accumulated for thousands of years, Palmer said.

Western Siberia is influenced by the Scandinavian pattern of atmospheric circulation, a climate connection that consists of a main circulation center over Scandinavia and opposing weaker centers over Western Europe and eastern Russia. Global warming makes the Scandinavian pattern transport more warmth and moisture to western Siberia from the North Atlantic. Together with soaring temperatures in western Siberia itself, this triggers extensive permafrost thaw and unlocks carbon that microbes can convert into methane.

Conversely, eastern Siberia is influenced by a climate pattern known as the Arctic Oscillation, which causes atmospheric air pressure to "seesaw" between the Arctic and the Northern Hemisphere's middle latitudes. Climate change affects the Arctic Oscillation, leading to persistent high-pressure systems that intensify heat waves, reduce cloud cover and promote wildfires in eastern Siberia, Palmer said.

The climate models showed that methane emissions will increase with temperature rise and that the increase could become steeper the hotter the world gets, triggering a feedback loop.

"Eastern Siberia appears to be the main driver of the projected increase because it is warming faster than western Siberia and has seen a sharp rise in extreme wildfires," Palmer said. "Whether that trend continues will depend on how much vegetation remains available to burn, but there is also evidence that fires may be accelerating permafrost thaw and the release of methane from previously frozen ground."

However, the rise in methane emissions reported in the study is small relative to global and projected future emissions, especially if wildfires are already destabilizing eastern Siberia's permafrost, Palmer said.

"Siberia's vast permafrost carbon store is a sleeping giant," he said. "Continued warming risks waking up a much larger source of greenhouse gases."

This iconic photo, captured by an American astronaut on board the International Space Station (ISS), shows a lengthy trail of thick smoke pouring across New York City in the immediate aftermath of the 9/11 attacks. A quarter of a century later, the image is as haunting as ever.

On the morning of Sept. 11, 2001, members of the terrorist group al-Qaeda hijacked four passenger airliners and crashed two of them into the twin towers — a pair of 110-story skyscrapers at the heart of the World Trade Center in lower Manhattan. The impact of these collisions, which occurred roughly 17 minutes apart, eventually caused both buildings to collapse.

Shortly after the second tower was hit, the third hijacked plane crashed into the Pentagon, the headquarters of the Department of Defense in Arlington, Virginia. Another attack — likely intended for Washington, D.C. — was thwarted when the passengers of a fourth plane fought back against their hijackers, causing the aircraft to crash near Shanksville, Pennsylvania. In total, 2,977 people were killed across the different attacks, according to the 9/11 Memorial and Museum.

NASA astronaut and ISS commander Frank Culbertson — the only American not on Earth at the time of the attacks — passed over New York City shortly after being told about what was happening back home. He photographed the thick plume of smoke blowing away from Manhattan, at an altitude of roughly 250 miles (400 kilometers) above Earth's surface.

If you look closely, you may be able to see what Culbertson described as an "odd bloom" around the base of the column of smoke rising from the towers. This is likely a sign that the image was captured "around the time of, or shortly after, the collapse of the second tower," Culbertson said.

Culbertson wrote several letters in the days following the attacks, sharing his unique perspective of the events. "It's horrible to see smoke pouring from wounds in your own country from such a fantastic vantage point," Culbertson wrote on Sept. 13. "The dichotomy of being on a spacecraft dedicated to improving life on the earth and watching life being destroyed by such willful, terrible acts is jolting to the psyche."

While in space, Culbertson learned that the pilot of the plane that was later hijacked and crashed into the Pentagon was his former flight school classmate Charles "Chic" Burlingame. When the ISS later passed over the Pentagon, the astronauts could see the large gash in the side of the building where the third plane had crashed. "Tears don't flow the same in space," Culbertson wrote while discussing his friend.

In 2017, Culbertson revealed that there was another striking thing he and the rest of his crew noticed in the wake of the attacks, according to Live Science's sister site Space.com. "One of the most startling effects was that within about two orbits, all of the contrails that are normally crisscrossing the United States had disappeared because they had grounded all the airplanes," he said.

However, there was one exception. The astronauts noticed a single contrail moving eastward across the Midwest. "That was Air Force One headed back to D.C. with President Bush," Culbertson said. It was a "very sobering" sight, he added.

See more Earth from space

"Protect our water," "Water for people not AI," "Don't mess with our water," declare protest signs from Texas to New Mexico to Arizona. Angered by water use, energy consumption and pollution, locals are increasingly protesting the rapid expansion of data centers in the United States as tech companies work to rapidly expand capacity for AI.

Many data centers rely at least partly on water to absorb heat from air or surfaces, and then cause cooling as it evaporates, just like sweating keeps our bodies cool. The processors inside data centers can reach internal temperatures of up to 176 degrees Fahrenheit, for the same reasons that an overtaxed laptop heats up.

But while there's little doubt that data centers are consuming significant amounts of energy, water consumption is more complicated. Claims circulating online bring scant clarity, ranging from articles claiming that chatbots can consume 500 ml of water per query to some online commentators declaring AI's water issue to be nonexistent. And the consumption data from large tech companies themselves are often incomplete and inconsistent.

Experts stress that, overall, data center water consumption pales in comparison to the usage by industries like agriculture and some kinds of manufacturing. Researchers have estimated that data center cooling systems consumed 66 billion liters of water in 2023, less than 1 percent of the nation’s total consumption.

That figure could considerably rise with the rapid buildout of AI data centers, however — which may not be a big problem for water-rich regions but could significantly add to local water stress in drought-strapped places like New Mexico and Arizona.

Fortunately, engineers say there's a host of things that can be done — and are being done — to reduce the strain on local water resources. "There are many good ideas out there," says energy systems expert Fengqi You of Cornell University. When you add in efforts to replenish and restore natural water resources, "there's a good chance that, eventually, it could be net-zero water for the on-site cooling."

More renewable energy and better siting

Recent advances in AI technology have already reduced water demand for many data centers. Electrical and computer engineer Shaolei Ren of the University of California, Riverside, says that an estimate he made based on GPT-4, an earlier version of the model powering ChatGPT, as recently as 2024 — that drafting a short email would consume 500 milliliters of water — is already outdated because AI models have become more efficient. (This study was the origin of the half-liter-per-query claim.) In 2025, Google estimated that five drops of water are spent on processing a median-length query with its chatbot Gemini.

But even tiny amounts add up, given the rise in AI use. You's group recently predicted that by 2030, US data centers could consume 731 billion to 1,125 billion liters annually — the latter roughly equivalent to New York City's annual drinking water supply.

Still, these numbers factor in not just cooling, but also a greater amount of water used to generate the electricity that powers data centers. Much of that comes from burning coal or gas, with water being used to cool steam back into liquid after it's been used to spin the electricity-generating turbines. In other words, AI's water consumption can be significantly reduced by shifting to solar and wind, which require little to no water to operate, You says.

You adds that companies should site data centers in areas less prone to drought and with ample renewable energy sources, like regions in Montana, Nebraska, parts of Texas and South Dakota, instead of constructing new data centers in water-stressed places, such as in Arizona, New Mexico and Southern California. Strategic siting along with other measures could reduce AI's future water footprint by up to 86 percent, he says.

New cooling technologies

Advances in cooling technologies are also helping. The newest data centers that specialize in AI are already more water-efficient than their predecessors.

Pre-AI data centers use fans to carry away the heat from processor-filled racks, then use chilling systems funneling cool water through the building to cool the warm air down again. The heated water is then fed into a cooling tower that removes the heat but also loses some of the water to the atmosphere. This evaporative cooling uses a lot of water, says Eric Masanet of the University of California, Santa Barbara, who researches data center sustainability.

But the energy-hungry processors inside AI data centers generate so much heat that it's hard to remove it with air alone. That’s why many tech companies — including Amazon, Microsoft and Google — use a more efficient technique called liquid cooling.

In this method, a system of pipes filled with water, sometimes mixed with temperature-regulating chemicals, runs on top of the hardware, cooling the processors directly rather than cooling the entire data center. And because this is a closed-loop system, no water is lost: The heated fluid can be cooled down by exposing the pipes to the outside air, if conditions are cool enough, or an air-conditioner-like system, which uses energy.

But when it's extremely hot or humid, the centers need to bring online extra, more effective methods that involve water; one of these is to mist the air around the pipes. Mechanical engineer Vaibhav Bahadur at the University of Texas at Austin says that most AI data centers in Texas only use this kind of water-based cooling for the hottest parts of the summer.

Still, he and his colleagues recently estimated that the state's growing number of data centers — which currently consume less than a percent of the state's water demand — could be using 3 to 9 percent of that water by 2040. He expects that figure to reduce considerably, though. "Data centers are becoming much more efficient in their water usage," he says.

Indeed, recent technological developments have made it easier to avoid water-based cooling, even in hot climates, says Josh Parker, head of sustainability for NVIDIA, the company that designs many of the processors that populate AI-specialized data centers. Their latest generation of processors run at such high temperatures that they can be cooled with water at around 113 degrees Fahrenheit which, Parker says, is significantly warmer than traditional approaches. That reduces the need to bring on water-based cooling. Unless local temperatures regularly exceed 113 Fahrenheit, a threshold generally crossed only during severe heat waves, "typically we can just get away with large efficient fans cooling the infrastructure and the ambient air is sufficient to pull the heat away," Parker says.

Ren cautions that some companies may not want to run their processors that hot because it can interfere with computational performance, while some also house non-AI servers in the same space that cannot take the heat. But other cooling technologies are in development.

Some of these rely on elaborately designed pipe systems that draw heat even more effectively from processors. A number of US companies are exploring immersion cooling, where data center hardware sits in a tank filled with cooling liquid. In China, some companies have taken a similar approach by installing data centers in the ocean, although this makes them hard to access should hardware need replacing or upgrading, Bahadur says.

Advances in cooling technology will be necessary for tech companies to meet sustainability goals they have set for their operations. According to a statement from Amazon, its Web Services "set a goal to be water positive by 2030 — returning more water to communities than our direct operations use — and as of 2024, we're more than halfway there."

A spokesperson for OpenAI points to a web page outlining the company's plans to minimize water use, while Google aims to replenish 120 percent of the freshwater its data centers consume by 2030 through a variety of water stewardship projects.

Some companies, such as Google, are also finding smart ways to use waste heat from data centers to help address other sustainability challenges, such as making building heating less reliant on fossil fuels. Across Europe, some data centers are funneling heat from cooling circuits into district heating systems used to warm buildings.

The future of AI's water usage hinges on decisions that tech companies, engineers and policymakers will make in the coming years, Masanet says: where data centers are sited, their local energy infrastructure and climate, and how they're designed. "If you choose one set of choices, your number is going to be off the charts," he says. "You choose another set of choices, it's going to be way down here."

This article originally appeared in Knowable Magazine, a nonprofit publication dedicated to making scientific knowledge accessible to all. Sign up for Knowable Magazine’s newsletter.

Large patches of open water were visible just 37 miles (60 kilometers) from the North Pole on Aug. 29, a NASA satellite image shows. Although this doesn't necessarily mean that Arctic ice is worse off this year than the past few years, the image reveals how severely climate change is affecting the region, experts say.

The image is from the NASA Worldview satellite photo browsing tool and was shared last week on the blog Arctic News. The patches are "quite striking," but it's not the first time that water has encroached upon Arctic ice in this way, said Julienne Stroeve, a professor of polar observation and modeling at University College London.

"We can see open water at times at the North Pole but I don't think it's ever been this extensive," Stroeve told Live Science in an email. For instance, the central Arctic Ocean and regions north of 80 degrees north latitude, an imaginary line that crosses Canada's Ellesmere Island and Spitsbergen in Norway, were highly fragmented in early September 2016.

The time of year is one reason water is now visible in this region, said Zachary Labe, a climate scientist at Climate Central, a nonprofit news organization that analyzes and reports on the climate. "By the end of summer, the sea ice generally becomes more fragmented, with areas of open water appearing more widespread between pieces of sea ice," Labe told Live Science in an email.

This means that local weather conditions and ocean currents can create large gaps between ice floes, Labe said. For example, strong winds can push ice fragments together or pull them apart, leading areas of water to widen or close within hours or days.

"Individual satellite images from around the North Pole in just the last two weeks show dramatic changes in the amount and location of visible open water," he noted.

The current extent of Arctic sea ice isn't particularly low when compared with record-setting years, but that's now very changeable due to the diffuseness of the ice, Stroeve said. "Winds could change and compress the ice into a more compact ice cover leading to sudden drops in total extent," she said.

There is no specific distance from the North Pole at which open water should normally stop, because Arctic conditions can vary substantially from year to year, Labe said. However, the summer ice has become thinner and more fragile in recent years, so open water is consistently reaching closer to the North Pole than it did before.

"To me, this image doesn't necessarily show that conditions are dramatically worse this year compared to other recent years," Labe said. "Instead, it represents a worrying snapshot of a very different Arctic Ocean than only a few decades ago and one that is quickly changing over time."

The Arctic is warming nearly four times faster than the global average. Some of the northernmost regions that have historically boasted expansive, thick and persistent ice at the end of summer now have young, brittle ice floes instead, Labe said.

"The broader implications of more open water across the Arctic Ocean are wide-ranging, from changes in local weather and ocean conditions to impacts on marine ecosystems and greater coastal risks like erosion and flooding for Arctic communities," he said.

Scientists expect that sea ice will start to refreeze by mid- to late September, closing at least some of the gaps.

With only a couple of months to go before the harvest season for winter wheat in Colorado, the crop faced a whiplash: After a warm, dry winter, a cold snap plunged the plants into freezing weather for 12 hours, and temperatures soared to nearly 90 degrees Fahrenheit (32.2 degrees Celsius) two days later. When the final harvest numbers were tallied in July, 73% of the crops were in poor or very poor condition. According to early estimates by Colorado Wheat, 2026's winter wheat crop was the smallest in the state since 1965.

Pick a crop, any crop, and you'll hear a similar story: Extreme weather and climate change are rocking the food supply. The warming climate makes food less nutritious, threatens crop survival, and triggers tipping points that would upend farming as we know it.

The impacts will be felt most intensely in less-developed regions of the world, where many people can't afford imported food and climate-related famines and nutritional scarcity are already happening.

But the U.S. is facing big changes to its food systems too, and no one is immune. Humans have overcome looming agricultural disasters before, but experts say the challenge should not be underestimated.

"There are real food security and nutrition concerns," said Andrew Hultgren, an environmental economist at the University of Illinois, Urbana-Champaign, "especially under these high-warming futures."

Food is becoming less nutritious

As the planet warms, food crops are expected to become less nutritious. That's because, due to plant biology that's not yet fully understood, crops grown under higher levels of carbon dioxide are deficient in zinc, protein, magnesium, iron and other micronutrients. Crops are already less nutritious than they were in the 1950s, but this is partly due to breeding decisions that prioritize yield over nutrition. The carbon dioxide deficiencies will exacerbate this nutrition decline.

The global monthly average concentration of carbon dioxide in the atmosphere is now over 420 parts per million (ppm), well over the preindustrial average of 280 ppm. By the end of the century, those levels will increase to at least 550 ppm in all but the most optimistic scenarios.

That will mean an additional 175 million people will be zinc deficient and an additional 122 million people will be protein deficient by 2050, a 2018 study found. Zinc deficiency has consequences for immune and skin health and may lead to poor growth in childhood; protein deficiency can also cause stunted growth as well as fatigue, muscle weakness and stress fractures. Those figures account only for the effects of carbon dioxide. A cascade of climate shifts and extreme weather may also affect the number of nutrients (and calories) available to the world.

The threats are myriad: Rising sea levels may inundate farmland and lead to saltier soil in coastal regions where, for example, rice farming is common. Soil salinity can make it impossible to grow crops in some regions. Droughts, heat waves, storms or temperature swings like those seen in Colorado this year might take out certain crops in particular places, leading to year-by-year price spikes or shortages. In the U.S., the results might look a lot like the recent egg shortages triggered by bird flu; temporarily empty shelves, price spikes, or even restrictions on the amount a customer can purchase in a visit for an affected food.

Climate shifts that harm pollinators and fuel the spread and introduction of plant pathogens such as harmful fungi will also likely reduce crop yields.

Areas that depend on the ocean for food are also facing steep challenges, due to both ocean acidification and the degradation of coral reef ecosystems, which are sources of food for many coastal communities and form much of the base of food chains for the larger fish people eat.

Hotter weather also affects food safety, said Christopher Golden, a professor of nutrition and public health at the Harvard T.H. Chan School of Public Health.

"Increasing sea temperature and increasing sedimentation within seas could lead to harmful algal blooms or increasing food poisoning events from temperature-related food spoilage," Golden said. Algal blooms can contaminate shellfish like oysters or scallops with neurotoxins that can sicken and kill people who eat them. Food spoilage is a concern in regions such as Madagascar, where catches are brought ashore and readied for consumption in the open air.

Meanwhile, fish may move poleward to avoid the hottest sea temperatures, leaving the most vulnerable regions ‪—‬ such as Southeast Asia, the Caribbean, Africa, Central America and the Pacific ‪—‬ with fewer fish in their waters. How bad this looks depends on the extent of the climate swings, with research suggesting that without any mitigation, fishers could see their catches decline by 58% to 92% off small islands in the Pacific and by 70% to 86% in Southeast Asia. This would drive food insecurity and malnutrition in those regions. The U.S. will likely face impacts too, as most of its seafood is imported from subtropical or tropical waters elsewhere.

There may be shifts in trade networks that lessen the blow for U.S. consumers, Golden said, but it's hard to predict. Some possibilities include "price shifts or trade shifts that lead to changing dietary patterns or more shelf-stable and heavily processed items that we know aren't good for your health," he said. In other words, less fresh-caught snapper and more potted meats.

Changing foods on the table

Individual producers are adapting, sometimes in ways that may not be immediately obvious to consumers. "Climate change is bad in that it's a slow-moving wave," said Elizabeth Wolkovich, a professor of forestry at the University of British Columbia. "You don't really notice that it's shifting underneath you and that the apple you eat isn't the apple your granddaughter will eat."

On that note, growers in the Pacific Northwest and U.S. Northeast will face challenges getting apples to lunch boxes around the world. Fewer cold days and more extreme-heat days will likely reduce apple yields by affecting how and when trees go dormant and bloom. Because it takes five or more years to establish fruiting trees in new regions, this could mean a reduced apple supply and higher prices.

Today's smooth arabica coffee (Coffea arabica) varieties may get harder to find and more expensive as climate change forces coffee growers out of many of the places they used to farm and droughts reduce supply. Earthier, more bitter robusta coffee beans (Coffea canephora) do better in warming temperatures, but even those beans could struggle with increasing seasonal variability caused by climate change.

Climate has already shifted wines in favor of less-acidic and higher-alcohol varieties, Wolkovich said, but it's happened slowly enough that, unless you're a connoisseur, you may not have noticed. Wine lovers can expect more changes: Wolkovich has found that the varieties of wine grapes that growers can produce will shift with climate change. Wildfires in grape-growing regions like California can also produce an unpleasant acrid and smoky flavor in wine.

And it's not just flavors that will be affected. U.S. dairy cattle breeds originated in cool and cloudy Northern Europe, and their milk output goes down as temperatures climb. Such heat stress reduced annual milk yield by an average of 1% a year between 2012 and 2016 alone, and heat-related losses are expected to balloon by 30% by 2050.

Americans have long been drinking less milk from the glass, but their demand for yogurt and cheese is rising, said Jared Hutchins, an assistant professor of agricultural and consumer economics at the University of Illinois Urbana-Champaign and first author of the study on milk yield. Those products depend heavily on the fat and protein content in milk, which is the first thing to drop when cattle are hot. "Fat and protein are what deliver the cultured dairy products that are in high demand," Hutchins told Live Science.

The story repeats itself across agricultural products, Hultgren said. "For each degree of that global temperature rise, caloric output [from crops] drops by 120 kilocalories or U.S. calories per person per day," he said, "which is about 4.5% of a person's daily recommended caloric intake."

That calculation, published by Hultgren and his colleagues in the journal Nature in 2025, already accounted for adaptations that farmers can make to reduce crop losses. Without those adaptations, the number would be over 30% higher, he said.

Reductions in available calories will translate to food shortages in vulnerable places, such as the Horn of Africa or India, said Marina Romanello, executive director of a multinational research project that tracks the impacts of climate on health at University College London. In North America, "it would feel like inflation," Hultgren said ‪—‬ yet another factor driving up grocery prices.

Worst-case scenarios

For farmers, the year-by-year uncertainty of climate change is a problem. Will this year bring drought? Will there be a sudden storm or flood that will wash away the spring crop? Should they take a risk on a new heat-resistant plant or agricultural technique?

Similar uncertainty haunts the long-term forecast. Climate tipping points can lead to sudden, irreversible changes in the system. For agriculture, one of the scariest tipping points is the potential collapse of the Atlantic Meridional Overturning Circulation (AMOC). This pattern of ocean currents brings warm surface water north from the equator and circulates cold water south, warming Northern Europe and the northern parts of North America and cooling the Southern Hemisphere.

If this current were to collapse, northwestern Europe would cool dramatically, with studies suggesting that London could see temperature lows of minus 4 F (minus 20 C) ‪— ‬colder than the city's lowest temperatures on record. Precipitation would decline across Europe, leading to drought. Meanwhile, in the Amazon, the wet season could become the dry season and vice versa, said René van Westen, a climate researcher at Utrecht University in the Netherlands who has studied the impacts of an AMOC collapse.

On the other hand, if the AMOC doesn't collapse, London is expected to warm by 4.9 F (2.7 C) and see 15% to 18% more precipitation, depending on the season. The uncertainty in these predictions makes preparations difficult. There is still a lot of controversy over whether the AMOC will collapse and, if so, when. Should farmers plan for England to become increasingly toasty, or should they expect it to be plunged into a little ice age?

AMOC-related changes will take decades to centuries to unfold, even with a total collapse, van Westen told Live Science. But even so, they would require a total rewriting of agriculture in Europe and the northeastern U.S. "It will be very challenging to adapt to such a scenario," he said.

That doesn't mean a collapse of the world food system is inevitable. Farmers are already adapting to the early impacts of climate change by scaling back water-hungry crops in drought years and, in some places, testing new, heat-resistant varieties of crops in an attempt to stem the losses.

And humans have overcome looming disaster in agriculture before: In the 1950s and 1960s, new varieties of rice and wheat, along with the availability of synthetic nitrogen fertilizers, spurred the "Green Revolution," tripling the world's yield of cereal crops while expanding farmland by only 30%. Similar innovations could limit hunger even as the world warms.

But the biggest way to mitigate these impacts is the most obvious one. While Hultgren and his colleagues found that adaptation could cut caloric losses under climate change by 30%, mitigating warming by reducing emissions today could slash them by half. Similarly, the AMOC is on a path toward weakening, van Westen said, but as long as humans slow the pace of climate change, the current can recover.

"If you are cutting your emissions," van Westen said, "you can lower your risk."

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Scientists have identified an ancient volcano on England's east coast that is so eroded, it took researchers three decades to piece together its enormous size and explosive past. What remains of the caldera system is located beneath the English counties of Norfolk and Lincolnshire.

However, while the volcano undoubtedly produced at least one huge-scale eruption, some experts don't think there is enough evidence for the structure to be called a supervolcano.

"It obviously must have been a very large eruption, but it would be very difficult to calculate the volume of the eruption given the poor preservation of the deposits," said Michael Poland, a research geophysicist with the Cascades Volcano Observatory and the scientist-in-charge of the Yellowstone Volcano Observatory. "This is part of the reason I really hate the term 'supervolcano,'" Poland, who was not involved in the discovery, told Live Science in an email.

In a recent analysis, published April 29 in the Geological Society of America Bulletin, scientists examined zircon crystals that were taken 80 years ago from boreholes 40 miles (65 kilometers) apart in Norfolk and Lincolnshire. Zircon crystals are smaller than the diameter of a human hair and form within molten magma underground before a volcano erupts. They contain uranium that decays into lead isotopes at a known rate, enabling researchers to precisely date eruptions.

The results showed an age match between the zircon crystals from Norfolk and Lincolnshire and counterparts taken from the Kinnekulle tephra, a thick layer of volcanic ash covering Scandinavia and the Baltic region. This suggests the ash plume from the volcano in what is now eastern England blew across the Tornquist Sea, a body of water that existed during the Ordovician period (488.3 million to 443.7 million years ago), and settled on what is now Scandinavia.

Researchers already knew that the Kinnekulle tephra was formed during a massive volcanic eruption. But the recent analysis shows for the first time how far the ash traveled and, therefore, how big the eruption really was.

The eruption would have also produced huge pyroclastic flows, or avalanches of rocky debris, ash and hot gas that race down the sides of some erupting volcanoes, said Peter Rowley, a volcanologist and senior lecturer at the University of Bristol in the U.K. who was not involved in the analysis. "The last eruption of this kind of scale was the Oranui event at Taupō in New Zealand, over 26,000 years ago," he told Live Science in an email.

However, while the explosion would have been impressive and equivalent to the force of thousands of atomic bombs, experts said the definition of a supervolcano is vague and there are better ways to describe what happened.

"The scientific definition of a supervolcano varies a little; it’s a term we tend not to use as volcanologists much," Rowley said. "In this case we would describe it as an ultraplinian eruption."

Ultraplinian eruptions are the most violent type of volcanic explosions, ejecting more than 240 cubic miles (1,000 cubic kilometers) of material. It's difficult to say exactly what the eruption that formed the Kinnekulle tephra would have looked like, but it likely lasted days to weeks and formed ash clouds taller than 25 miles (40 km) that reached into the stratosphere.

Geologists tend to reject the term supervolcano because it is imprecise, instead preferring to describe eruptions by the volume of material they eject.

Stephen Self, a physical volcanologist at the University of California, Berkeley, agreed that the term supervolcano can be too vague. "Supervolcano has become a kind-of buzz-word," he told Live Science in an email. "It's the deposits of the eruptions that are recognized, not the volcano."

Very little of the material ejected in England's ultraplinian eruption remains today, because most of it was eroded or buried. "The geological record is far from complete so it can be very difficult to say much about these eruption volumes with very old volcanoes," Rowley said.

Similarly, the Kinnekulle tephra has been degraded over time, Poland said.

The analysis also found evidence for an earlier eruption of the volcano that occurred 453.7 million years ago. However, there is no trace of these eruptions at the surface today; the boreholes are located in some of England's flattest landscapes, study first author Tim Pharaoh, a geophysicist with the British Geological Survey, said in a statement in August.

It's not surprising to find traces of big, ancient volcanoes in England. The recently identified volcano is part of a wider volcanic system that was active 450 million years ago and includes Eryri National Park in Wales and the Lake District in northwestern England, Rowley said.

"It's best not to imagine whole preserved volcanoes, but rather that we have deposits from their eruptions, or rocks which formed in the magma reservoirs beneath the original volcano," Rowley said. "These are often deformed and altered by tectonic events meaning that it takes some careful geological investigation to interpret the true picture."

China's solar power capacity has overtaken coal for the first time, marking a major milestone in the country's rapid expansion of renewable energy.

China had about 1,288 gigawatts (GW) of installed solar capacity at the end of July, compared with 1,285 GW of coal-fired capacity, according to figures from the country's energy administration reported by the South China Morning Post.

The milestone could have major implications for global efforts to tackle climate change: China is the world's largest annual greenhouse gas emitter, accounting for around 30% of global planet-warming emissions. If its rapid expansion of renewable energy begins to displace coal-fired power ‪—‬ one of the country's primary sources of greenhouse gas emissions ‪—‬ the impact could extend well beyond Chinese borders.

"China reaching around 1,288 GW of installed solar capacity, marginally overtaking coal, is a major milestone," Matthew Davies, UNESCO chair in sustainable energy technologies and a professor of chemical engineering at Swansea University in the U.K., told Live Science.

However, installed capacity doesn't necessarily equate to actual electricity generation. "Solar only generates when sunlight is available, whereas coal plants can run for much longer periods, so solar still supplies a much smaller share of China's electricity than coal," Davies said.

In other words, China has more solar capacity than coal capacity, but coal remains far more important when it comes to the amount of electricity actually delivered to the grid.

Between January and July this year, Chinese solar power output rose 15.5% compared to the same time period in 2025. Over those seven months, it reached 802.4 TWh, which is around 13% of the country's total electricity consumption.

"I would see this as a structural turning point, not the point at which solar has replaced coal," Davies said. "The key question is whether renewable generation can grow fast enough not only to meet rising electricity demand but to push coal generation down in absolute terms. Given the scale of China's power system, sustained reductions in coal use could have a major impact on global CO₂ emissions."

To do that, China will need to do more than build solar farms. One of the biggest challenges will be integrating all of the new renewable power into the electricity system.

"Installing solar is only part of the transition; grids, transmission, storage and demand flexibility all need to keep pace so that renewable electricity can actually be used," Davies said.

This transition toward solar panels will also make renewable energy more accessible around the world, as China's enormous manufacturing capacity will help drive down the global cost of solar panels. However, Davies said the next phase of the transition is to ensure the whole solar production process is sustainable. "We need to think about where technologies are made, where materials come from, how long they last, and how they are reused or recycled," he said.

Solar panel manufacturing involves raw material extraction, processing, manufacture, transport and installation, so it has an initial carbon footprint. High energy requirement for polysilicon production is a considerable factor as it uses coal-fired power plants. But, this is offset by the electricity they generate.

There is also a case for expanding local and regional manufacturing, Davies noted. Doing so could strengthen supply chains, create local skills and economic value, and make the global energy transition more resilient and equitable. That could be particularly important for expanding access to electricity in parts of the world where reliable power remains limited.

"The global energy transition is not only about replacing fossil fuels in existing electricity systems; it is also about enabling people who still lack reliable electricity to gain access to clean, affordable power," Davies said. "Ultimately, success is not simply about installing more solar panels. It is about building a clean-energy system that is affordable, sustainable, resilient and accessible globally."

A massive volcano erupts in Southeast Asia. Ash fall delays flights and destroys crops, while pyroclastic flows wipe out entire towns. Over the following weeks, the sulfur dioxide pumped out turns into a haze of fine acid droplets, eventually wrapping around the entire planet, scattering sunlight back to space. The sun turns pale, shadows go soft, the sky glows violet after sunset and the ground below cools. The next summer never appears. Harvests fail from the American Midwest to the monsoon belt in Asia. Countries close their borders, and people who have never heard of the volcano begin to starve.

This nightmare scenario has yet to happen, but it's not a matter of if but when a world-changing event like this will hit, and governments need to start preparing for global catastrophes that could disrupt the food system on an unprecedented scale.

There are three main steps we need to take soon: put events like nuclear war, a huge volcanic eruption and a continent-wide blackout into national risk assessments; agree to trade rules for such an emergency before it arrives; and fund pilot projects now for foods so we know what can be produced at scale without much sunlight or without fertilizer.

We've been faced with turbulent times the last few years with COVID, the Russian invasion of Ukraine and the Iran war. And the current outlook indicates there's more trouble ahead — the closure of the Strait of Hormuz alone could disrupt global food production, for example. A significant part of the world's traded fertilizer passes through it, and the United Nations Food and Agriculture Organization has warned that the shortfall will cut yields into 2027.

This shows that in today’s interconnected world, regional crises will influence countries far away from it. With larger catastrophes, these ripple effects in the global system would be more widespread, quicker to take hold and on a higher magnitude.

Critics might question why we need to prepare for such Black Swan events. But global catastrophes are not as unlikely as they feel. Ice cores enable us to count large eruptions of the past. On that basis, volcanologists put the chance of a magnitude 7 eruption — the size of Tambora in 1815, which caused a "year without summer" — at roughly 1 in 6 this century. Estimates for a repeat of the 1859 Carrington solar storm, which could disrupt power grids on a continental scale, run from about 1% to 12% per decade. Nuclear-armed states are almost constantly engaged in conflicts, risking nuclear war.

Each of these events might seem unlikely. But in combination, they add up to a significant chance that at least one of them will happen this century.

What they all have in common is that they all would drastically impact the food system. A volcanic eruption, the firestorms of a nuclear war or a large asteroid impact all push particles into the upper atmosphere that block sunlight, which would lead to colder, drier growing seasons that could result in harvest losses up to total failure. In the most extreme nuclear war scenario, researchers estimate that global calorie production could drop by around 90%. A long blackout, caused by a powerful solar storm for example, works differently but has the same consequence: no fertilizer, no pesticides, no fuel, and the sharpest yield losses exactly where we produce most food today.

Hardly anyone is assessing these risks. Even the countries doing it best fall short. The U.K. and Switzerland are good examples. The U.K. National Risk Register lists 89 risks, including volcanic eruptions, severe space weather, pandemics and a nuclear miscalculation abroad. However, the catastrophic events it considers are all relatively small-scale — with a "reasonable" worst-case scenario of over 1,000 deaths and a cost of tens of billions of pounds — and the register does not even begin to consider events like a global famine or a nuclear war that could lead to tens of millions of deaths and cost trillions of pounds.

Switzerland's national risk analysis, meanwhile, covers 44 hazards including a solar storm, a foreign volcanic eruption and a meteor strike. Again, the scale is too small. The volcano is a moderate European eruption and the meteor is 66 feet (20 meters) across, comparable to the Chelyabinsk impact in 2013. Many other countries do not even consider risk on these limited scales.

No country can solve this alone. In a review, my colleagues and I highlighted the key factors that would make countries and communities more resilient to various global catastrophes. These include food self-sufficiency, decentralization, geographic isolation and governance quality — meaning working institutions, low corruption and low inequality. Australia scores best, but even Australia would struggle without imported fuel, medicine and fertilizer. Nowhere is a refuge on its own.

Countries will need international collaboration to make it through a crisis of this scale. Export bans have been a common reflex in food crises of the past. After a global catastrophe, they would only isolate countries from each other and lead to further damage, as export bans can easily lead to the situation where enough food is still around, but nobody is trading it and so people starve.

We need to work on rules to govern trade under those circumstances before a global emergency occurs.

You might say the probabilities are too small to justify the cost, and that money spent on hypothetical volcanoes is money not spent on floods, hospitals and defense. This criticism might land if you only look at a single catastrophe. However, there is a whole portfolio of events that could lead to global catastrophe. In combination, there is a good chance that one of them will hit, and if it does, we better be prepared. Also, many of the preparations needed are not even that expensive. Low-input farming, decentralized grids, a diverse food supply and more exhaustive risk assessment are within grasp of most countries.

This needs to happen now. Starting work on resilient foods or better international agreements when a global catastrophe has already occurred is too late. You cannot start an industry in the month the harvest fails. Clearly, prevention is better than resilience, but some of these events cannot be prevented at all. When one of them arrives, the difference between the societies that prepared and those that did not will be measured in lives.

Opinion on Live Science gives you insight on the most important issues in science that affect you and the world around you today, written by experts and leading scientists in their field.

This striking satellite snap shows a series of ghostly green lakes that merged into a single murky entity after several years of unusual weather in the Australian outback.

The entwined lakes are located in Barkly Tableland, an area within Australia's Northern Territory, which lies between the states of Queensland, South Australia and Western Australia. The largest section of the conglomerate is Tarrabool Lake (on the left side of the photo), which stretches around 55 miles (90 kilometers) across at its widest point. It is dark green due to the dense vegetation and algae in the water.

The smaller half of the merged lakes (on the right side of the image) is made up of three lakes: Lake Sylvester, Lake Corella and Lake Deburgh. This section has a paler and chalkier hue due to high levels of suspended sediment. This is likely because the lakes have overflowed and mixed together, whipping up the dust and topsoil that once surrounded them. (Several other, smaller lakes of various sizes and shades of green can also be seen throughout the image.)

All of these lakes are ephemeral, meaning they have no constant inflow or outflow of water, much like most of Australia's other lakes. As a result, they almost completely dry out during prolonged periods of sunny weather, as high temperatures cause the water inside them to evaporate, and then reappear as heavy rainfall refills the basins.

However, across the two years prior to this image, there was so much rain that the lakes never dried out. Instead, they continued to grow year over year, as you can see from additional satellite imagery (see below), which shows the same area between 2022 and 2024.

The Northern Territory's rainy season lasts between October and April. Both the 2022-2023 and 2023-2024 rainy seasons, which preceded the 2024 satellite photos, were ranked among the top 10 wettest since 1990, according to NASA's Earth Observatory, which released these images.

Although this is extreme, it is not that surprising, considering that annual rainfall in the Barkly Tableland rose by around 14% between 1989 and 2018, according to a report from the Australian Bureau of Meteorology. This is likely due to the effects of human-caused climate change.

On top of the general increase in rainfall, Tropical Cyclone Megan dumped a massive amount of rain on the region in March 2024. The resulting flash flooding was so great that fish were seen swimming across a nearby road, Australia's ABC News previously reported.

In the winter, Tarrabool Lake and Lake Sylvester are important breeding sites for birds, including the straw-necked ibis (Threskiornis spinicollis) and the Australian pelican (Pelecanus conspicillatus), and BirdLife International lists both lakes as important bird areas. At its fullest, Tarrabool Lake also floods the surrounding Eva Downs Swamp system, creating Australia's largest wooded swamp.

See more Earth from space

In July, a government agency tasked with protecting our cultural heritage abdicated its responsibility, voting to further industry's pursuit of profit over protecting sites of cultural significance. The Advisory Council on Historic Preservation (ACHP), the only federal agency whose sole mission is promoting preservation of America’s historic places, voted to advance a proposed new rule that would make sweeping changes to how Section 106 of the National Historic Preservation Act is implemented. By doing so, the Council is opening the door for federal agencies to bulldoze sacred Indigenous sites and important archaeological sites.

Section 106 requires federal agencies to assess the effects of their actions — or the actions they license or permit — on historic, archaeological, and cultural properties listed in or eligible for listing in the National Register of Historic Places. Additionally, agencies must attempt, to the extent possible, to minimize harmful effects on these significant places. The rules governing Section 106 have been in place since 1974. As part of that framework, the government is legally required to consult with Tribal Nations about projects that may destroy or damage their sacred places or culturally significant resources.

The proposed new regulations destroy the idea behind consultation. For instance, they would give federal agencies the discretion to decide whether public participation will be useful. Essentially, the agencies get to decide whether to notify the public or provide opportunity for public comment before they approve projects that might damage or destroy historic properties.

It would also give federal agencies the right to approve projects that may damage or destroy Tribal sacred places and other culturally significant resources without consulting with Tribal Nations or seeking their expertise about them. This violates federal law and jurisprudence, which recognizes Tribal Nations as "domestic, dependent nations," and requires consultation with them on a government-to-government basis; Tribal Nations are not merely “interested parties” like community organizations or local groups.

An agency official would prepare a "Section 106 report" that identifies historic properties, assesses impacts, and makes a determination on next steps; this Section 106 report would then be circulated to State Historic Preservation Officers, Tribal Historic Preservation Officers, and all relevant consulting parties — including project proponents — who would have an opportunity to comment on the findings. The agency official must only review those comments; officials have no obligation to respond to or incorporate any of those comments before issuing the final decision, shifting Section 106 from its previous consensus-seeking exercise to one where the agency official simply decides.

The new regulations also remove vast swaths of our history from protection. To be considered a historic property, the new regulations say it must include, or have included, tangible human improvements – built structures – AND the historic property must be geographically compact. This change in definition will exclude entire categories of historic places from meaningful consideration under Section 106 in the future, including battlefields like Gettysburg or the Little Bighorn, cultural landscapes like Devil’s Tower in Wyoming or the Black Hills in South Dakota, archaeological resources like petroglyphs in Chaco Canyon. It lessens protection on places like the Grand Canyon, simply because they are not “geographically compact” or centered on a building or other structure.

The new regulations specifically preclude "noncompact, unimproved natural features such as mountains, valleys, bodies of water, or landscapes, including ethnographic landscapes" — locations that carry great spiritual and historical meaning to American Indian groups. Many traditional cultural places and sacred sites of deep religious and cultural significance to Tribes, Native Hawaiian organizations, and local communities will automatically be excluded from consideration for protection by the new regulations.

The changed definition of "historic property" in the new regulations will remove protections for 99% of American Indian heritage and could result in the erasure of the heritage of an entire group of people in the United States – those who lived here before European colonization.

Mitigation, or trying to prevent, minimize or offset any damage to a historic site, becomes a “maybe,” as the federal agency undertaking the project decides whether the "value" of the property is worth the cost of mitigation. "Reasonable mitigation" is redefined so that federal agencies only have to consider measures to lessen the impact of a project on a historic property if they are "technically and economically feasible."

The new regulations water down the definition of what is considered to be an "Adverse Effect" on historic properties so that they are close to meaningless. By removing indirect and cumulative effects on historic properties and eliminating the visual, atmospheric or audible elements that diminish the experience at a property, the new regulations could say that building and operating a casino or amusement park on Mount Vernon would not be considered an Adverse Effect.

Additionally, agencies will not be required to avoid or minimize adverse effects. They can simply document that “other considerations outweigh” historic preservation and proceed as they wish.

Advocates of the new regulations argue that the existing regulations for protecting historic places slow down projects and make economic development more expensive than necessary. They say these new regulations create a system that allows industry to plan better with more precise information, and the processes and procedures are better explained. They argue that the narrower definitions and expanded exemptions could mean faster, more predictable reviews. In reality, however, the rules that are already in place seek to balance the need for economic development with the need to protect the fabric of America’s heritage.

I remember urban renewal and its impact on Oklahoma City in the early 1960s, as large, beautiful buildings in the downtown area were bulldozed to rubble and hauled away so that new, shiny structures could replace them. I remember entire neighborhoods of working-class people being leveled so that an Interstate highway could be constructed through the center of town to let millions of people speed through without having to see the “urban blight” that was erased. I remember, too, the historic properties that disappeared under the developer’s bulldozers and graders.

Those memories are fading fast, I must admit, and the historic properties are long gone. The National Historic Preservation Act was established to help prevent the destruction of the property of economically weaker groups of people at the behest of the economically strong without some level of consideration of the heritage under threat by construction; the Section 106 regulations grew out as a result of that time and has been seen to be a good compromise between economic development and economic justice.

The new regulations serve to weaken everything that has worked about Section 106 for the last 50 years so the federal government has the power to quickly green-light industry's ground-disturbing projects without considering the impact of its actions on America’s heritage. Agencies may proceed as they wish, since the new regulations mute the voices of states, tribes, and local communities who are at the forefront of identifying and protecting American heritage.

The new regulations are currently under review with the Office of Information and Regulatory Affairs (OIRA) within the White House Office of Management and Budget.

There is a chance that the administration will use a rushed rulemaking process that bypasses public comment, meaning the regulations will take effect when published.

But bringing visibility to the proposed changes could potentially forestall that, and so people who are concerned should contact their local congressional representatives to tell them the changes are a threat to all American's heritage.

If these changes are not stopped, our children will hold us accountable for letting our shared heritage be erased merely for the convenience and benefit of a few.

Opinion on Live Science gives you insight on the most important issues in science that affect you and the world around you today, written by experts and leading scientists in their field.

This dramatic astronaut photo shows a highly active stratovolcano in Tanzania that was recently adorned with a striking white "crown" of ash. The explosive volcano produces a rare type of lava that is unusually cool, uniquely colored and the fastest-flowing on Earth.

The volcano is officially named Ol Doinyo Lengai and stands up to 9,718 feet (2,692 meters) above the grassy plains of the Arusha region of northern Tanzania. The local Maasai people call the towering peak the "Mountain of God," because they believe it is the residence of the supreme creator god Ngai (also known as Engai or Enkai), according to the book "Sacred Mountains of the World" (Cambridge University Press, 2022).

Ol Doinyo Lengai is one of Africa's most active volcanoes; it has been erupting on and off for the past 15,000 years. It alternates between effusive eruptions, where lava seeps out of its vents, and sporadic explosive outbursts, which can drastically alter its appearance. Its most recent eruption, which is effusive, has been going on since April 2017, according to the Smithsonian Institution's Global Volcanism Program.

The sacred mountain produces a rare type of lava that consists of natrocarbonatite rock, which is rich in sodium, potassium and calcium carbonate but low in silica. As a result, it is much cooler than most other lava, dipping to temperatures below 1,100 degrees Fahrenheit (600 degrees Celsius). It also has an unusually low viscosity, which makes it "some of the fastest-flowing lava in the world," according to NASA's Earth Observatory.

When it solidifies, this unusually runny lava turns surprisingly pale, due to chemical reactions with rainwater and moisture in the air. In this image, you can see several lightly colored rivers of rock snaking down the volcano's flank. The youngest of these lava flows was created during an eruption in 1998.

For most of the past century, Ol Doinyo Lengai's summit consisted of a bowl-like depression that gradually filled with lava. But between 2007 and 2008, a series of major explosive eruptions birthed a 330-foot-tall (100 m) ash cone that now looms over the summit's center.

This explosive event has transformed the volcano's appearance when viewed from space, additional photos from the Earth Observatory show. In the featured image, a dark spot of fresh lava can be seen in the center of the cone, making it look like a crown.

Ol Doinyo Lengai is located in the East African Rift System, a roughly 2,000-mile long (3,500 kilometers) area surrounding a divergent fault line where the African Plate is splitting into the Somali and Nubian plates.

This region has been tectonically active for more than 25 million years and has created some of the continent's most interesting topographic features, including Mount Kilimanjaro and Mount Kenya, which are located on each side of Ol Doinyo Lengai, according to the Earth Observatory.

The godly mountain is around 10 miles (16 km) south of Lake Natron, a red salt lake that's famed for its large flamingo populations. The geographical features are often photographed alongside one another.

See more Earth from space

This article was originally published by Yale Environment 360.

Near-extinct oryx are returning. Farms are prospering as irrigation water reaches fields for the first time in decades. Farmers are even nurturing new trees on their land. Once a byword for drought and famine, the African Sahel region on the southern flank of the Sahara Desert now has more water than it has for decades. Wells are filling as water tables have risen by 13 feet or more in places. Lake Chad, which was one of Africa's largest expanses of water before shriveling during the droughts, is recovering.

Over years of drought in the late 20th century, the sun hard baked the soils of the Sahel. Now, erratic but extreme rains are returning to this semi-arid region, causing lethal floods but also replenishing rivers, filling desert depressions, restoring water to dried riverbeds known as wadis, and sluicing rainwater off impermeable soils directly into aquifers. The process began in the 1990s but has accelerated in the past five years.

"Across the Sahel, from Ethiopia to Senegal, we have evidence of increased terrestrial water storage," says Richard Taylor, a hydrogeologist at University College London who has led ground teams investigating the relationships between climate, land use, and groundwater recharge in the region.

But increased rainfall since the drought years of the 1970s and 1980s explains only some of the rewetting of the Sahel. It cannot fully account for the transformation, say researchers. Also driving the rewetting, they posit, are changes to the land surface, ranging from the internationally funded Great Green Wall project to the revival of traditional water harvesting methods and the chaos caused by jihadist militants, which has led to the abandonment of irrigation projects that once emptied rivers of their flows.

Much remains unclear in these remote lands on the edge of the Sahara Desert, but the trend seems set to be long-term, with climate scientists saying more — and more extreme — rainfall is on the way in the 21st century. As underground water reserves revive, some are forecasting an agricultural renaissance.

The Sahel is a band of semi-arid land around 500 miles wide that stretches across North Africa, from Senegal in the west to Ethiopia in the east, with a fast-growing population above 150 million. It is a transition zone between the Sahara Desert in the north and savanna grasslands and coastal forests to the south. Water is everything in the Sahel. Its rains are critical to human survival, but they have been sporadic and unpredictable since the close of a humid era around 5,000 years ago.

How much rain the Sahel gets depends on the West African monsoon, a wet wind that sweeps north from the Gulf of Guinea between June and September, and on how far the monsoon penetrates into the interior. Whether it reaches the 15th parallel north of the equator or stalls at the 10th parallel make the difference between a good year and a failed harvest, say hydrologists.

During the droughts of the late 20th century, as the monsoon repeatedly fell short, up to a million people died of hunger and disease. But now, with a strengthening monsoon, there is talk among scientists of the Sahel being on the verge of a new humid era.

That is good news for wildlife. With wadi systems reviving in Chad's Ouadi Rimé-Ouadi Achim nature reserve, conservationists are documenting resurgent numbers of aardvarks, porcupines, badgers, and foxes, and the successful reintroduction of the scimitar-horned oryx, which was once declared extinct in the wild but now numbers more than 600 individuals. Elsewhere, West African giraffes are browsing on verdant vegetation in areas from which they had disappeared.

As the rains return, farmers have boosted crop yields by nurturing the natural regrowth of some 200 million trees on formerly treeless fields in southern Niger, according to former World Resources Institute geographer Chris Reij. And, supported by new aid programs such as the World Bank's regional recovery program PROLAC, they are re-establishing small-scale irrigation systems by tapping groundwater around resurgent oases in Chad, Niger, and Cameroon.

"In the past … there was not enough water to irrigate crops, and our harvests were meager. Now our lives have changed," Achta, a farmer in Chad, said last year. She now has water to plant on four times as much land and has doubled her onion crop. The Bank says her story "reflects a broader transformation across the Lake Chad basin."

Most places in the Sahel are seeing more rainfall. And that rain has become concentrated in extreme downpours from clusters of violent thunderstorms, known to meteorologists as Mesoscale Convective Systems, that occasionally bubble up during the monsoon season. Sahelian storm clusters are now rated as some of the most powerful on the planet, and they deliver most of the region's rainfall. There has been a threefold increase in the frequency of extreme storms since the 1980s, according to a recent analysis.

Why the revival of the rains? An assessment published in 2021 by the U.N.'s Intergovernmental Panel on Climate Change found "high confidence" among climate scientists that it is a result of strong warming in the North Atlantic, caused by a combination of global heating and a reduction, in Europe and North America, of sulphate aerosols from coal burning, which once created a thin haze that cooled the ocean. That cooling prevented the northward migration of the West African monsoon into the Sahel, resulting in drought. But the clean-up has warmed the ocean and pulled the monsoon back into the Sahel, strengthening its ability to produce deluges.

The effects of these mega-storms are especially challenging in a region more used to disasters caused by the absence of rain. Niger, one of the world’s 10 poorest countries, saw tens of thousands die from famine during the late 20th century droughts. Now, it sees more deaths from floods than droughts. Fierce storms during the 2024 monsoon season inundated the capital, Niamey, and in rural areas washed away more than 150,000 mud-brick homes.

Sudden downpours are initially destructive, but they are a boon to underground water reserves. Falling onto compacted ground, the water does not initially infiltrate the soil but rushes into rivers and dry wadis, which speed the water's flow into aquifers.

Hydrologists say that this indirect infiltration is most intense after heavy storms. "In some locations, rainfall intensity is more important than the annual rainfall amount in determining the magnitude of groundwater recharge," says Taylor. This intensity, he says, is a major cause of the rapid rising of water tables — especially since, in the Sahel, most water drains not to the ocean but inland to depressions and lakes.

Not only are new ponds forming across the formerly arid lands; ancient networks of wadis are being restored. And Taylor's network of researchers has found wells across the region refilling. Mean water tables in much of Niger have risen by some 13 feet, indicating a 15 percent increase in aquifer reserves.

This local data is now being corroborated by analysis from satellites that measure changes in land mass by tracking subtle changes in gravitational force from the land below. NASA's Gravity Recovery and Climate Experiment mission has found a sharp increase in gravitational force across the Sahel in the past two decades that hydrologists attribute to growing terrestrial water storage.

But rainfall and its intensity are only part of the story. Events on land also play a part.

Environmentalists have long held that the encroachment of agriculture into the Sahel during the 20th century caused "desertification" by removing natural vegetation, destroying soils, and allowing the advance of desert sands. But hydrologically, the effect may be the opposite because some crops can actually help the land retain water.

All vegetation absorbs moisture from the soil before transpiring it into the air. But shallow-rooted African grain crops such as millet and sorghum transpire less moisture than the deeper-rooted grasses they replace, leaving more moisture in the soil.

An amplifying factor is the drought-driven crusting of soils, which has increased runoff by around 50 percent in the central Sahel in recent decades. Analysis by Christophe Peugeot, a hydrologist at the HydroSciences laboratory at the University of Montpellier in France, found that the droughts "have permanently transformed the region's soils… fueling today's floods."

Much of this runoff ends up in Lake Chad, on the border between Nigeria, Cameroon, Chad, and Niger, which drains an area almost six times the size of California. The lake's dramatic demise became a totemic image of the late 20th century hydrological decline of the Sahel. But less well known is that the lake is now recovering, as water inflows increase. Hydrogeologists at the University of N'Djamena in Chad report that in 2024 it swelled to a peak of more than 9,000 square miles, almost as big as in the 1960s and 10 times its size in the mid-1980s.

This growth is partly masked by large areas of saturated vegetation in the lake that do not show up in satellite images, say hydrologists. But as the lake grows, the aquifer beneath is also refilling.

Some researchers argue that deliberate efforts to capture rain in soils can also help explain the rising groundwaters across the region. One such effort is the Great Green Wall. Originally planned as a barrier of planted trees to prevent the advance of the Sahara, it has morphed into more grassroots efforts to control soil erosion by capturing rainfall and improving soil moisture, all of which can improve infiltration underground.

Many such projects revive traditional water-harvesting techniques, including the placement of stones along hill contours, digging small holes known as "zai pits" amid crops, and forming crescent-shaped mounds around trees.

Alpha Lo of the Climate Water Project, who highlighted the restored Sahelian groundwaters in a recent online analysis, argues that such techniques are "the primary reason." But most researchers believe that, while locally effective in nurturing trees or crops, they are not happening at sufficient scale to explain the region-wide resurgence.

A final suggestion is that humans are extracting less water from rivers, leaving more to eventually infiltrate into aquifers. One driver of this trend is the decline of big irrigation projects that were constructed during the drought years to boost food production. For instance, Cameroon once largely emptied the River Logone, historically the biggest single source of water flowing into Lake Chad, to grow rice. But the SEMRY irrigation project reportedly diverts much less water now, due to poor management, aging infrastructure, and the outmigration of farmers.

In areas around Lake Chad, farmers have also abandoned their irrigated fields because of Boko Haram, a militant jihadist group that continues to terrorize communities. Timmo Gaasbeek, food security policy officer at the Netherlands Ministry of Foreign Affairs, says the chaos in northern Nigeria "means that the water in the rivers is not caught upstream, and continues to flow into Lake Chad, where it contributes to higher water levels and more groundwater recharge."

Most climate models predict a further increase in annual rainfall in the coming decades, due to global heating and the banishing of cooling aerosols from the North Atlantic. Taylor predicts that "the Sahel will experience particularly marked increases in extreme rain" that will "serve to increase groundwater recharge."

Peugeot says that "the increased availability of water in valley bottoms could promote the development of irrigation, offering new prospects in several Sahelian regions." Buoyed by such predictions, Nigeria is looking to restore the 165,000-acre South Chad Irrigation Project on the former shores of Lake Chad, which has long been abandoned for want of water.

But the road ahead will not be straightforward. Sahel rains will continue to be erratic on all timescales. Most immediately, climatologists are predicting that this year's strong El Niño event could deliver drought in the eastern Sahel, but bumper rains and more floods further west.

Yams and sweet potatoes are often confused, and the names are sometimes used interchangeably in the U.S. However, they're two different crops. So what sets them apart?

The differences lie mainly in these vegetables' classifications, plant growth, and nutritional profiles, experts told Live Science.

Despite both growing underground and appearing somewhat similar, "Botanically, sweet potatoes and yams are not closely related, as they belong to different plant families," said Phillip Wadl, a research geneticist at the U.S. Vegetable Laboratory in Charleston, South Carolina. Sweet potatoes (Ipomoea batatas) are in the morning glory family (Convolvulaceae). Yams (Dioscorea), by contrast, belong to the Dioscoreaceae family, and there are 11 yam species cultivated for food and income, Wadl told Live Science in an email.

Yams and sweet potatoes also belong to different plant groups, or "cotyledon types," said Jeffrey Cole Denis Gregorie, a sweet potato specialist at the Sweet Potato Research Station in Chase, Louisiana. Yams are monocots, plants whose embryo has only one cotyledon, or seed leaf, like grasses and lilies. Sweet potatoes are dicots, plants with two embryonic seed leaves, which include many fruits and vegetables, such as grapes, squash, strawberries and tomatoes.

In addition, yams and sweet potatoes store food in different parts of the plant. "Sweet potatoes form storage roots which are enlarged parts of the root system," Wadl explained, "whereas yams form tubers, which are enlarged underground stems for nutrient storage."

A single sweet potato plant typically produces about four to 10 sweet potatoes, while a yam plant yields about one to five yams. Sweet potatoes generally take about three to five months to mature, compared with about six months to a full year for yams, according to Craig Yencho, a professor of horticultural science and a sweet potato and potato researcher with North Carolina State University.

How do you tell sweet potatoes and yams apart?

Visually, sweet potatoes and yams are easy to tell apart when you know what to look for. Sweet potatoes tend to be shorter and blockier, with tapered ends. Yams are usually long and cylindrical, sometimes with "toes," or branching shapes.

Sweet potatoes come in various flesh colors, including orange ‪—‬ the most common color in the U.S. ‪—‬ as well as yellow, purple and white. Their skin is typically thin and smooth, whereas "yams often have a rough, bark-like skin and their flesh can be white, purple or reddish," Wadl said. One well-known purple yam, known as ube (Dioscorea alata), is a popular ingredient in treats such as ice cream, cookies and pound cake.

Sweet potatoes and yams also have noticeable differences in their culinary and nutritional profiles, Wadl said. "Sweet potatoes are generally sweeter and have a moist, creamy texture when cooked, although dry types are available," he explained. "Yams, on the other hand, tend to be starchier, drier, and have a more earthy, sometimes less sweet, flavor compared to sweet potatoes. Their texture can be more like a regular potato."

Nutritionally, the two crops are quite different, too. Sweet potatoes, particularly the orange-fleshed varieties, are an excellent source of beta-carotene (a precursor to vitamin A), vitamin C, dietary fiber, potassium and some B vitamins. "While nutritious, [yams] typically contain less beta-carotene than orange sweet potatoes," Wadl noted. Instead, yams are a good source of potassium, vitamin C, manganese and dietary fiber.

Sweet potatoes are generally considered safe to eat both raw and cooked, Wadl said. By contrast, many wild varieties of true yams, especially those not cultivated for commercial consumption, contain compounds like dioscorine that could make them toxic to humans if eaten raw. "These must be thoroughly cooked to remove the toxins and make them safe for consumption," Wadl said.

Thanksgiving confusion around yams and sweet potatoes

If yams and sweet potatoes are so different, why do so many Americans call sweet potatoes "yams"?

Part of the answer lies in history. The yam was a key provision on voyages of enslaved people from West Africa to the Americas, "used to feed captives a familiar food," said Judith Carney, a professor of geography at UCLA. "In mainland plantation societies of North America where the African yam could not be grown, the sweet potato served as a substitute dietary staple." Because the two crops shared some characteristics, "the word 'yam' came to refer vernacularly to both tubers in mainland America, as we see in the U.S. today," Carney told Live Science in an email.

The U.S. sweet potato industry also leaned into the confusion, adopting the term "yam" for marketing reasons, Gregorie told Live Science in an email. "In the United States, many orange-fleshed, moist varieties of sweet potatoes are often mislabeled as "yams" to distinguish them from the drier, white-fleshed sweet potato varieties," Wadl explained.

As a result, the "yams" at most U.S. supermarkets are probably sweet potatoes. "Garnet yams" and "jewel yams" aren't actually yams, despite those labels; instead, they're softer, sweeter varieties of sweet potatoes, according to the University of California, Davis.

Although genuine yams are sold in many international markets in the U.S, "if you're buying a "yam" in a typical U.S. supermarket, you're almost certainly purchasing a sweet potato," Wadl said.

Do you know where pumpkins and blueberries come from? Find out with our fruits and vegetables quiz!

Nestled within Brazil's Cerrado tropical savanna — the second-largest biome in South America, after the Amazon rainforest — Uberaba Geopark is a time capsule from the Late Cretaceous period (100.5 million to 66 million years ago).

The geopark boasts abundant, well-preserved fossils from the last chapters of the nonavian-dinosaur era, according to UNESCO, earning it the nickname the "Land of the Giants," or "Terra dos Gigantes" in Portuguese. Paleontologists have discovered more than 10,000 fossils belonging to dinosaurs, prehistoric crocodyliforms (a group encompassing living crocodiles, alligators, caimans and gharials, as well as their extinct relatives), turtles and other ancient creatures within the park's boundaries.

One of the best-known discoveries is the fossil of Uberabatitan ribeiroi, a titanosaur measuring 89 feet (27 meters) long and 33 feet (10 m) tall, according to UNESCO.

The finds were clustered in impressive geological features, including the Serra da Galga formation and Serra Geral mountain range. These structures formed from ancient basalt flows, which came from giant volcanic eruptions that predate the breakup of the Gondwana supercontinent 180 million years ago.

The park has the ideal conditions to preserve fossils because it alternated between shallow lagoons and river systems when the dinosaurs roamed the region, meaning the animals' remains were conserved in mud when they died.

Serra da Galga and Serra Geral also overlie one of the world's largest freshwater reservoirs, the Guarani aquifer, which supplies drinking water for more than 100 cities in Brazil, Argentina, Paraguay and Uruguay.

The Cerrado savanna, which houses the entire park, is a critical-yet-underprotected carbon sink that hosts more than 12,000 plant species and diverse animal life.

The "Land of the Giants" was added to UNESCO's list of geoparks in 2024 in recognition of the region's geological and natural heritage.

What is now the Uberaba Geopark was the birthplace of Brazil's modern livestock market, which is one of the biggest in the world. Farmers in the 19th century introduced zebu (Bos indicus) cattle from India because they are better suited to the climate in Brazil and require less food than common domesticated cattle (Bos taurus). Zebu cattle also produce lower greenhouse gas emissions than common domesticated cattle do, according to UNESCO.

Uberaba Geopark is open to visitors. There are several museums and trails to explore, including one that leads to the Vale Encantado, or "Enchanted Valley," which contains forests, waterfalls and prehistoric rock formations, according to the BBC.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

The Caspian Sea, the world's largest inland body of water, is in major trouble. Since the mid-1990s, this saline lake, located between Europe and Asia, has lost an area nearly the size of Sicily. But until now, it wasn't clear why.

Researchers finally provided answers in a study published June 5 in the journal Earth's Future. Using ground- and satellite-based observations, they connected falling water levels to a drastic drop in river inputs from Iran, Turkmenistan, Azerbaijan, Kazakhstan and Russia, all of which border the Caspian Sea.

The team particularly highlighted losses from Russia's Volga River, the longest river in Europe, which supplies roughly 80% of the Caspian's inflow.

To find out why the Volga is discharging less water into the Caspian Sea now than it did 30 years ago, we spoke with Amir AghaKouchak, a co-author of the study and professor of civil and environmental engineering at the University of California, Irvine.

AghaKouchak, who directs UC Irvine's Center for Hydrometeorology and Remote Sensing, explained why river inputs have dropped and how decades of water withdrawals have put the Caspian Sea on a path to collapse. He also touched on a solution to this crisis — and revealed why Russia's hunger for ammunition to attack Ukraine is making it harder to save the Caspian Sea.

Sascha Pare: Falling water levels in the Caspian Sea have been attributed to natural variability, and more recently, there's been a focus on climate change and increased evaporation due to rising temperatures. But what did the results of your study show?

Amir AghaKouchak: People quickly jump to conclusions about climate change. Of course, that is important, but it cannot explain the change that we have observed. Over the last 30 years, water levels in the Caspian Sea have shrunk by around 2 meters [6.5 feet] or so. Just to put things in perspective, this translates to about 24,000 square kilometers [9,300 square miles] of sea area loss — about 5%. When we look at drivers, we notice that rainfall hasn't changed significantly over the lake and upstream, so the decline cannot be explained simply by changes in rain.

Evaporation has increased, so it explains maybe about one-third of the change. There is less water in the lake, and that indicates there's probably some water lost along the way. We don't have a lot of human-related data ‪—‬ for example, water withdrawal for irrigation or groundwater wells. That area is very difficult; the countries are not open to sharing data. A lot of our results are based on looking at proxies. Our interpretation is that temperature caused about 30% of the change and the rest is probably because of human activities.

SP: Which human activities does your research suggest are responsible for the Caspian Sea's decline?

AA: Several of the countries on the Caspian Sea have built large dams — Russia, for example. They are all desperate for hydropower. All of the countries around the lake [have also built infrastructure to supply agriculture], and one reason is that they want to create jobs and improve the local economy. Water demand is increasing in all those countries around the Caspian Sea. It's not surprising to see lakes drying or groundwater levels falling.

It's hard to find data about how much water countries are using; they keep data very private, especially places like Russia. We don't have detailed information, but the Volga-Don Canal in Russia is one of the projects that is contributing to this crisis. [Editor's note: The Volga-Don Canal is a ship canal that connects the Volga and Don rivers at their closest points.]

But we cannot blame this whole thing on that. We have to be careful with our language; we can't say one project is responsible. Most likely, this is the collective impact of many different small withdrawals from here and there, overall contributing to a significant decline in the Volga River outflow into the lake. In the paper, we have different rivers, but the Volga dominates because it's the largest river. The Volga has a higher impact than all the other rivers combined. There are lots of demands along that river basin.

SP: Did you expect human activities to play such a big role, or were you surprised?

AA: We did not have any expectations at the beginning. In fact, when we started this project, I reached out to a lot of colleagues from neighboring countries around the Caspian Sea. We didn't want to do it on our own, sitting in California, looking at another area of the world, without having local people involved. If you look at the co-authors, you see people from Azerbaijan, Iran, Kazakhstan — so, we have local experts. We thought this was really important to have those perspectives. I didn't want to reflect the opinions of only one research group. What we have here is the collective opinion of people who have not met in person; we only exchanged emails to look at the results, and then we came up with those conclusions.

We do have a Russian involved, but not from an official Russian institution. I thought this was really important, because there's more back-and-forth [with a large group of people]. If two people have to convince themselves of an idea, it's much easier than with 20. Also, we brought in people from other countries who had projects in the area; for example, there is one group from Finland and another group from Germany. We tried to come up with something that this large group of people could agree on. It was not easy, but it worked out.

SP: What is the worst-case future scenario for the Caspian Sea if shoreline countries fail to decrease their water demands?

AA: My concern is that, in the same general area, we have the Aral Sea, which is now about 5% to 10% of what it used to be, and Lake Urmia, in northwest Iran, that has also shrunk really fast and is now very small, with low levels of ecological activity. So we have two smaller lakes in a very similar climate that, from an ecological perspective, are dead. Because we have seen those degrade, we have to consider that this is the worst-case scenario for the Caspian Sea, too.

The Caspian Sea is much, much bigger. I hope it doesn't happen, but it's on the same path. Again, it's much larger, so it would probably take 100 years [to shrink as much as the Aral Sea and Lake Urmia], even with the current trend. But because we have seen those lakes shrink really fast, it deserves attention. Due to the size of this lake, the potential impacts will be huge. Even if 20% of the Caspian Sea dries out, the consequences will be very significant. It would be a disaster.

SP: You mentioned that drying lakes can become ecologically "dead." What other impacts could the Caspian Sea's falling water levels have on the surrounding landscape and people?

AA: The lake's retreat will expose the lake bed, and because it's saline, you have all kinds of minerals that will be exposed. With the next strong wind, they will go into the air. The health impacts include respiratory diseases, and even eye diseases, that are linked to salt minerals in the atmosphere. Those are the immediate consequences. Additionally, those minerals can travel long distances. In general, salt deposition on agricultural land reduces productivity. It takes a while, but if those lands are exposed for a long time, this will have an impact on the agricultural sector in those areas, which means potential food security issues. We don't exactly know what those materials are on the lake bed, so it's hard to know precisely what the consequences will be.

There is also serious shipping happening in this region. Right now, most of the shrinking is happening in the Caspian Sea's northern part, which is shallower [than the rest of the lake]. The drop in water levels is about 2 meters, and you can imagine that if you have a port and water levels drop more, you won't be able to operate. You'll need to extend your shipping routes southward; you'll need to invest and spend a lot of money to use other ports and docking sites. We have evidence of that around the Aral Sea and also Lake Urmia. There used to be these docking sites and ports, but those are now far away from the water.

SP: What must bordering countries do to save the Caspian Sea and prevent these negative effects?

AA: Demand management is absolutely critical. Demand management doesn't get a lot of attention, because unlike big projects that make the news, management means you have to cut things and do things that people don't notice. Some people argue that politicians don't show a lot of interest in demand management, but it's something that we have control over. The technological opportunities are there.

But when you look at that area, there is a big war ‪—‬ so probably it's not the priority to invest in management. There are a lot of things that we don't talk about in the paper that are relevant. I recently learned through discussions with people from the region — this is something that came to us from co-authors and collaborators — that many countries in that area grow cotton, which uses a lot of water. It has a lot of applications, but apparently, one of them is military. Cotton is used to produce ammunition. Russia needs a lot of ammunition, so not only are they growing it themselves, but they also bought neighboring reserves from Uzbekistan and Kazakhstan. So now, even those countries have an incentive to grow more cotton. This is driving more irrigation, more groundwater extraction, more surface water depletion, and probably more impacts on the Caspian Sea.

This interview has been condensed and edited lightly for clarity.

Each year, tons of soil, silt and rocks flow into reservoirs in the U.S. and get stuck there, creating a "ticking time bomb" that threatens lives and livelihoods. According to a new study, around a fifth of the world's reservoirs are currently at high risk of filling with sediment, and by 2060, half could be inoperable as a result.

The sediment takes up space meant for water, putting additional pressure on structures that were not built to contain large quantities of sand and sludge. As the reservoir fills with the material instead of water, sediment-filled reservoirs pose a serious threat to water security and the safety of people living near or downstream of them — and as the climate changes, scientists expect the problem to worsen.

"We are losing storage space in our reservoirs faster from sediment accumulation than we gain space from new dam construction," Amy East, a geologist at the U.S. Geological Survey, told Live Science.

What is dam sedimentation?

Dam sedimentation is not a uniquely U.S. problem. Rain pulls sediment down slopes into waterways. Normally, this sediment would travel through the river system, shaping the water flow, creating habitats, and fortifying coastal wetlands and estuaries against erosion. In many parts of the world, this sediment is also a vital natural fertilizer for crops. But after a river is dammed, this sediment can collect in the reservoir.

A 2023 study published in the journal Science found that sediment buildup was the greatest threat to global water storage in existing reservoirs — even more than drought.

New research, which includes smaller reservoirs, has offered a more nuanced and concerning picture. In the study, published June 5 in the journal Nature Sustainability, researchers assessed the state of reservoir sedimentation globally. They looked at more than 550,000 reservoirs, most of which spanned less than 0.4 square miles (1 square kilometre). They found that almost 1 in 5 of reservoirs globally are at high risk of filling up with sediment.

The researchers found that sedimentation is eating into global reservoir storage capacity at about 7.3% every decade. There are 16 global hotspots that are at high risk of reservoir sedimentation, threatening water supplies to more than 2 billion people and impacting more than a quarter of global irrigated land. One of these hotspots includes the western U.S.

The authors found that sedimentation risk was especially pronounced in regions with dense small-reservoir networks supporting key crop systems.

"Without intervention, we project that, by 2060, more than half of all reservoirs could become functionally inoperable," the authors wrote. This includes more than half of all small reservoirs and more than a third of large reservoirs globally.

Where is it a problem in the U.S.?

North America has the second largest number of reservoirs, after Asia, according to the global survey. And at 7.8%, its sedimentation rate is higher than the global average, ranking it third after Oceania (9.9%) and South America (8.1%),

The U.S. is home to many small dams, said Matthias Kondolf, a geomorphologist at the University of California, Berkeley who wasn't involved in the study. "All the focus tends to be on the big dams, and these many, many small ones have been neglected," he told Live Science.

From the 1940s to 1970s, there was a big push by the U.S. government to build "farm ponds," he said. In western Oklahoma, for example, "all these dams are now filling up with sediment, and there's nothing in place to assess the safety of these features, which have now become threats."

Some of these dams have already failed, following large storms as the ageing dams were not able to cope with the volume of water. A 2018 study found that since 1980, there have been on average 24 dam failures a year in the U.S.

Reservoirs in some regions are more at risk than others. The western U.S. is a natural hotspot because it has a steeper topography, meaning more sediment naturally ends up in watersheds, East, who wasn't involved in the new research, said.

And in areas where human activities like farming or logging disrupt the landscape, rainfall is likely to drag even more sediment into reservoirs, East said. "Those types of land use can create sediment-producing hotspots almost anywhere."

In California, for example, more than half of small reservoirs in maize-growing areas are filling up with sediment at a rate of more than 10% a year, which threatens local maize production.

The threat to water security will be particularly acute in places struggling with wildfires, such as the western U.S. After fires, rain washes the debris and sediment into watersheds. A 2024 study in California found that most of this post-fire sediment erosion occurred upstream of reservoirs, rather than in places where sediment would move downstream directly to the ocean.

The dam-sedimentation situation is likely to get worse as the climate changes, researchers said. As the climate changes, there will be more extreme weather events, such as droughts and wildfires, adding more sediment to watersheds. Dams are designed to cope with the pressure of water, not sediment which exerts more force on dam walls. Moreover, in seismically active areas, the sediment vibrates at a different frequency than the concrete of the dam, which creates further impact against the structure. Additionally, the dams are just getting older.

"What do we do 50 or 100 years from now when we have all these reservoirs across the landscape filled with sediment, sitting there as ticking time bombs?" Kondolf said.

What can be done about it?

For a reservoir to be sustainable long-term, the amount of sediment entering it and leaving it should be the same.

"A big part of preventing reservoir sedimentation problems is upstream soil conservation in the watershed," East said. Interventions include ensuring that land use, such as agriculture or timber harvesting, follow best practice to reduce the amount of sediment washing off the landscapes.

If sediment is already in the dam, it can be difficult to manage and expensive to remediate, Kondolf said. Some dams, such as Fall Creek Dam in Oregon, have mechanisms that enable engineers to release sediment. But in the past, reservoirs were not designed to manage sediment and little thought was given to how to decommission them.

"This is one of those issues that falls in the cracks between different agencies and responsibilities," Kondolf said. Some larger facilities fall under the remit of the federal government. Other dams fall under state governments. California, for example, recently launched a state-sponsored program to future-proof the state's dams.

But smaller dams often get overlooked, Kondolf said.

One option is to remove the dams entirely. For example, sediment-related concerns contributed to the decision to remove the Elwha and Glines Canyon dams in Washington. The Elwha River later carried most of the sediment to its river mouth.

For smaller dams with a relatively small amount of sediment, "you just blow up the dam and let the sediment work its way downstream", Kondolf said.

There are other technological solutions, but they are expensive, such as retrofitting dams to enable them to pass sediment; creating a bypass to route sediment-heavy water around the dam; and mechanical dredging.

Another option is to empty the reservoir of water and let the river cut a channel through the sediment, Kondolf said.

However, released dam sediment brings its own risks. If not managed carefully, sediment can flood the river system and disrupt downstream ecosystems.

"The economics of managing reservoir sediment long-term were not generally incorporated into dam design and planning in the last century when many western-U.S. water projects began," East said. This has "pushed the cost burden on future generations."

But the reality is that reservoirs around the country are filling with sediment. It is reducing their ability to store water and potentially endangering the communities living downstream of them — and unless addressed, the problem will only get worse.

Scientists have confirmed that a flowering plant native to the mountains in southwest China is carnivorous, supporting a prediction made by Charles Darwin more than 150 years ago.

The species, Saxifraga candelabrum, grows at elevations above 8,200 feet (2,500 meters) in the Hengduan Mountains, which connect the southeast portions of the Tibetan Plateau to the Yunnan-Guizhou Plateau.

The plant has stems and branches covered in sticky hairs that can trap small insects, predominantly nonbiting midges. However, scientists were unsure if these insects were being ingested by the plant. In a new study, researchers showed that S. candelabrum can digest and absorb nutrients from insects after capturing them, proving that the plant is carnivorous. The scientists published their findings Tuesday (Aug. 4) in the journal Nature Communications.

This is the first demonstrated case of carnivory in the saxifrage plant group, said study co-author Douglas Soltis, a distinguished professor of biology at the Florida Museum of Natural History.

Other carnivorous plants typically grow in moist, boggy soils, but S. candelabrum is found in dry alpine areas, Soltis told Live Science in an email. "These are all nitrate poor soils — that's why this carnivorous habit has evolved a number of times" to supplement the plants in vital nutrients, he said.

In 1875, Darwin theorized that two species closely related to S. candelabrum that also have sticky hairs — S. rotundifolia and S. umbrosa — may be carnivorous, based on their ability to catch insects. But the 19th-century naturalist couldn't show that the plants digested their prey or reused the nutrients in insect tissues — two conditions that are key to confirming carnivory in plants. Without these conditions, a species is considered simply "protocarnivorous," meaning it catches and kills insects or other small animals but doesn't digest or absorb them, according to the study.

"Although untested at the time, Darwin’s hypothesis provided an important inspiration for our study," study co-author Hang Sun, a researcher in the Chinese Academy of Sciences' Kunming Institute of Botany, told Live Science in an email.

The researchers conducted field observations and herbarium surveys of S. candelabrum, which revealed that mature plants with more numerous and longer branches had an average of 71 trapped insects on them. In the herbarium surveys, the team found that 43 out of 45 specimens had caught insects, suggesting that insect-trapping is a widespread phenomenon in this species.

Next, the study's authors showed that S. candelabrum possesses phosphatase, a digestive enzyme commonly found in carnivorous plants. They did this by labeling the phosphatase enzymes with fluorescent molecules to visualize them under a specialized microscope, a technique known as fluorescence tagging.

To determine if S. candelabrum digests and absorbs nutrients from insects, the researchers labeled fruit flies with a stable form of nitrogen before feeding them to the plants. This led to a marked rise in stable nitrogen in S. candelabrum and in a different, known carnivorous species, which the team used as a control group. By contrast, a non-carnivorous plant that formed a second control group did not show an increase in stable nitrogen, indicating that S. candelabrum is carnivorous.

Finally, the researchers performed a genetic analysis, which revealed that S. candelabrum has genes in common with known carnivorous plants that are linked to prey attraction, digestion and nutrient absorption. Together, the results showed that S. candelabrum evolved carnivorous traits to cope with its nutrient-poor environment, adapting its hairs — which were initially used for herbivore defense — into insect traps, according to the study.

Larger insects, which S. candelabrum requires for pollination, rarely get stuck to the hairs, the researchers noted in the study, suggesting that the species has perfectly balanced its needs through evolution.

Other Saxifraga species and plants belonging to the same lineage could turn out to be carnivorous, too.

"Many members of the Saxifragaceae, which includes genera other than Saxifraga, have sticky glandular hairs and are often covered with insects," Soltis said. "I would not be surprised if other members of the family are also carnivorous — as Darwin predicted."

The study broadens the scope of carnivorous plant research, Sun said. "Carnivory may therefore be far more widespread among flowering plants than previously recognized," he said.

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