For more than seven decades, phosphorus has represented one of the great paradoxes in the study of the origin of life. This element, indispensable for the existence of living beings as we know them, forms the structural backbone of DNA and RNA, allows cells to store and transfer energy through the molecule adenosine triphosphate (ATP), […]
From the rim of Jezero Crater, Earth is only a bright point in the sky. On July 2, NASA’s Perseverance rover watched that point vanish behind Phobos, Mars’ larger moon, and recorded the event with its Mastcam-Z camera. The sequence is the first time humanity has observed Earth disappearing behind an object from the surface […]
What's in the photo? The lava-stained slopes and ash cone of a highly active volcano
Who took the photo? An unnamed astronaut on board the International Space Station
When was it taken? Oct. 6, 2020
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.
Lake Natron, near Ol Doinyo Lengai, hosts large flamingo populations. (Image credit: TONY KARUMBA/AFP via Getty Images)
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.
A 2020 astronaut photo shows three uniquely colored lakes — Tahoe, Walker and Mono — straddling contrasting biomes on either side of the California-Nevada border.
More than 140 million miles away from Earth, a rare event recently occurred in the twilight skies above Mars, and it was all captured on camera by NASA’s Perseverance rover.
Imagery of a celestial alignment, featuring Earth as it briefly vanished behind the Martian moon Phobos, was revealed in composite photos captured by Perseverance’s Mastcam-Z instrument in early July as the intrepid rover embarked on its 1,907th Martian day, or sol, on the Red Planet.
The rover’s Mastcam-Z camera system, developed by Arizona State University in collaboration with Malin Space Science Systems, was built for capturing high-resolution panoramic zoom imagery of the Martian landscape. Although its main objectives involve its investigations of Jezero Crater and ancient geological features preserved there for eons, which may even include evidence of past microbial life, cases like the recent celestial alignment showcase how the rover’s cameras can also provide unique insights into astronomical events.
A sequence of composite images (after color correction) reveals the irregularly-shaped Martian moon Phobos with Earth, appearing as a tiny point of light, disappearing behind it (Image Credit: NASA/JPL-Caltech/ASU/MSSS/SSI)
A Robot on Mars Captures an Occultation
Captured against fading twilight, our Earthly home appears as little more than a tiny, bright speck of light as it slowly passes behind the irregularly shaped Martian moon, in what astronomers refer to as an occultation.
NASA applied processing to the rare images, which helped to filter out some of the background light, revealing the brief celestial pairing in greater detail. The resulting imagery offers a glimpse of a dark backdrop that now better highlights the motion of Earth and Phobos in their treks through the Martian sky.
A Sunset Unlike Any Other
The image was obtained roughly 40 minutes after the Martian sunset, as the natural orbital path Phobos follows causes it to appear to drift upward in the new sequence of images, while Earth moves diagonally downward, then slips out of view behind the oddly shaped Martian companion.
Imagery with enhanced inset of the Martian moon Phobos with Earth visible behind it (Image Credit: NASA/JPL-Caltech/ASU/MSSS/SSI)
In an annotated version released by NASA, timestamps spanning just 40 seconds illustrate the progression of the event in single frames, offering a look at a sunset unlike any ever seen on Earth.
That isn’t to say that the same effect can’t be seen from our planet, but in reverse: a lunar occultation where Mars passes behind the Moon can also be observed here, under the right conditions.
Occultations are frequently used by astronomers to help study the positions and motions of various celestial bodies in this way. However, seeing one from the surface of another planet is a rare treat, offering a view of Earth as a distant point of light.
In the past, Perseverance has also captured images of a lunar eclipse from its position on the Martian surface, as Phobos was seen passing in front of the Sun. Past imagery collected by NASA’s robotic explorer has also documented appearances of the Martian moon Deimos in the Red Planet’s early morning skies.
Colors of Change on a Red Planet
Although Mars’ characteristic rusty hues are ever-present, the recent imagery also offers a glimpse of other subtle colors seen in the Martian environment, particularly at twilight. With subtle bluish grays that gradually transition to redder tones, the new images offer a more nuanced and colorful look at the Red Planet.
Close up of the original composite images before color adjustments, where Phobos can be faintly seen against the Martian twilight, with Earth appearing as a speck of light behind it (Image Credit: NASA/JPL-Caltech/ASU/MSSS/SSI).
Perseverance has now spent more than five years exploring Mars, and its ongoing discoveries have added a wealth of new information to the growing body of knowledge scientists have collected about our nearby planetary neighbor.
As for the recent imagery the rover captured, such a unique view requires careful timing, along with a bit of good fortune, according to Mark Lemmon, a Mastcam-Z co-investigator at the Space Science Institute in Boulder, Colorado.
“Phobos crosses the Martian sky three times a day, and Earth is visible for months at a stretch,” Lemmon said in a statement, adding that “catching one directly behind the other takes planning and a little luck.”
Additional details provided by NASA about the new imagery can be found here and here.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached atmicah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.
The economist John Maynard Keynes once remarked, “In the long run we are all dead.” From an astronomical standpoint, this is true for the Earth itself. In roughly 5 billion years, the Sun will exhaust the hydrogen at its core and enter the next phase of its life as a Red Giant, where it will swell up large enough to engulf and destroy the Earth.
Currently, the Sun is still in its main-sequence phase, where it fuses hydrogen into helium in its core. Although it remains relatively stable during this phase, it will gradually grow brighter with time. As the Sun shines brighter, the increased heat and radiation will raise Earth’s surface temperature, potentially pushing it past the threshold for life to survive.
One of Earth’s geological processes that helps regulate its surface temperature is the carbon cycle. Over millions of years, carbon moves from the Earth’s interior into the atmosphere as carbon dioxide or CO2, where it functions as a greenhouse gas that traps heat. Plants take in this CO2 through photosynthesis and move carbon through the biosphere.
Meanwhile, rain and rock weathering draw carbon into the oceans and rocks. By pulling CO2 out of the atmosphere, the carbon cycle could mitigate Earth’s warming as the Sun brightens over time. Today, human activities are increasing atmospheric CO2 and warming the planet. However, over billions of years, the carbon cycle could gradually remove enough CO2 from the atmosphere that eventually too little would remain to support photosynthesis.
With these challenges to life on Earth in mind, the researchers Jacob Haqq‐Misra and Eric Wolf investigated how long Earth’s biosphere could last in the distant future. The team used computer models to calculate the balance of energy that Earth would receive and emit over time, accounting for the effects of increasing sunlight and changing atmospheric CO2 concentrations. They followed this up with calculations using the ExoCAM model to determine the temperature and atmospheric conditions of future Earth across different latitudes. They related these conditions to a habitability metric to determine their impact on the biosphere.
To estimate the biosphere’s maximum possible lifespan, the team conducted 29 simulations representing the planet’s conditions over the next 2 billion years. In one set of simulations, the Earth’s carbon cycle contributed little to regulating surface temperature, with the atmosphere’s CO2 concentration fixed at approximately modern levels of 400 parts per million (ppm) and surface temperatures continuing to increase. In another, the carbon cycle worked to keep Earth’s average surface temperature fixed at the modern average of approximately 59℉ (15℃), no matter how much it had to reduce CO2 in the atmosphere.
In the scenario with a fixed CO2 concentration, the team found that in 1.7 billion years, Earth’s surface reached an average of 122°F (50°C), which is too hot for most land plants. After 1.9 billion years, it reached 149°F (65°), becoming too hot for all land plants to survive as temperatures continued to rise.
They also found that in the fixed average surface temperature scenario, atmospheric CO2 dropped below the 150 ppm level that most plants require for photosynthesis within 500 million years. After 1.4 billion years, CO2 levels fell below 10 ppm, leaving only a few land photosynthesizers and aquatic plants alive. After about 1.8 billion years, atmospheric CO2 dropped to 1 ppm, leaving only microbes capable of photosynthesis.
The researchers’ findings generally extend the estimated lifetime of Earth’s future biosphere compared with earlier, simpler models that suggested maximum lifespans of 100 million to 1.5 billion years. However, they clarified that other scientists should verify their results by running tests with other models, especially under extreme conditions of high incoming solar radiation and low atmospheric CO2.
Lastly, Haqq‐Misra and Wolf noted that their model did not account for major evolutionary changes that could help life adapt to future conditions. Over time, plants could evolve to tolerate higher temperatures or lower atmospheric CO2 levels. Future humans or another intelligent species might also engage in large-scale geoengineering projects to prevent the end of life on Earth. If life on Earth proves adaptable enough, the biosphere may endure until a Red Giant fills the daytime sky.
Concentrations of chlorophyll in the equatorial Pacific deviate from normal during El Niño events. These maps depict monthly average chlorophyll concentrations for June 2025 (left), under neutral conditions, and June 2026 (right), as El Niño was strengthening. Data come from the OCI (Ocean Color Instrument) on NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite and are based on measurements of green and blue light from the ocean reflected back to the sensor. NASA Earth Observatory images by Michala Garrison.
As of June 2026, El Niño has officially arrived. This naturally recurring phenomenon is characterized by warmer-than-normal water temperatures in parts of the equatorial Pacific along with changes to atmospheric and oceanic circulation patterns. Its regional effects range from desert floods to delayed monsoons to shifts in where tropical cyclones are more likely to form.
NOAA’s Climate Prediction Center expects the current El Niño to continue to strengthen through the end of 2026, with a 97 percent chance of lasting through early Northern Hemisphere spring 2027. Even during El Niño’s early stages, satellites have observed characteristic changes along the equatorial Pacific, such as warmer-than-normal sea surface temperatures and higher-than-normal sea surface height.
Among the first ecological downstream effects are changes to the marine food web. The maps above show chlorophyll-a concentrations—the pigment present in most phytoplankton—as observed by the OCI (Ocean Color Instrument) on NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite. In June 2025 (left), conditions were neutral, while in June 2026 (right), El Niño was strengthening.
The most noticeable difference appears in the central Pacific, around the equator due north of New Zealand: chlorophyll concentrations, an indication of phytoplankton abundance, are substantially lower in 2026. This change is expected, said Matthew Kehrli and Graham Trolley, oceanographers in the Ocean Ecology Laboratory at NASA’s Goddard Space Flight Center. That’s because during an El Niño, easterly equatorial trade winds weaken, the warm surface layer of the ocean extends deeper, and the upwelling of cool, nutrient-rich water that typically fuels phytoplankton growth is suppressed.
As the El Niño progresses, the scientists anticipate the differences in the central Pacific will become more pronounced. “This may manifest as a greater difference in values across the current region, as a broadening region of reduced surface chlorophyll-a concentration, or both, depending on the behavior of the equatorial trade winds,” they said.
Reductions in phytoplankton have ripple effects through the marine food web, including in coastal regions. Less food is available for zooplankton, as well as for fish, seabirds, and marine mammals. Peru’s anchovy fisheries have seen profound declines in catch during past El Niños, driven similarly by warmer surface waters, reduced upwelling, and lower phytoplankton abundance. In 2026, Peru’s Ministry of Production repeatedly suspended the fishery to safeguard the country’s main fishing resource. Pelicans have been seen venturing into Peruvian ports and urban areas in search of food.
Although the disruptions to marine life can be severe, a post-El Niño “chlorophyll rebound,” with higher-than-normal concentrations in the equatorial Pacific, can occur. Research suggests that higher iron concentrations delivered in ocean currents, as well as dust arriving from drier land in parts of Central and South America, help fuel the resurgence—a rebound that doesn’t require a follow-on La Niña. La Niña, which often follows El Niño events, can also produce elevated chlorophyll concentrations. A strong La Niña in 1998–1999 set off a large phytoplankton bloom in the eastern Pacific and a dramatic increase in fish populations.
Scientists have new tools available for studying this sort of variability. The PACE mission launched in February 2024, making this the first complete El Niño event for which the satellite will gather global, near-daily hyperspectral measurements. “The scientific community will be able to observe the 2026 El Niño with data across more wavelengths of light than ever before,” Kehrli and Trolley said.
To better understand effects on life in the ocean, researchers hope to use PACE data to gauge the responses of specific phytoplankton communities to El Niño. And the possibilities extend beyond the marine realm, the scientists note. PACE’s sensors can measure plant pigment composition on land and clouds and aerosols in the atmosphere, all of which are influenced by El Niño.
Satellites designed to provide internet service are now serving an unexpected second purpose: helping scientists map the nearly invisible atmosphere at the edge of space. Researchers at Kyoto University have used orbital changes from about 1,200 Starlink satellites to map Earth’s thermosphere, a thin and difficult-to-observe region of the upper atmosphere. Their analysis produced the [...]
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.
Shallow groundwater storage in February 2003 and February 2025, as compared to the average from 1948 to 2012. (Image credit: NASA / Adapted by Yale Environment 360)
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 streets of the Keurs Massar area in Dakar are flooded on Sept. 7, 2020 after a monsoon in Senegal. (Image credit: SEYLLOU via Getty Images)
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.
Dead trees in an arm of Lake Chad near Kiskawa, Chad, that was recently flooded. (Image credit: JORIS BOLOMEY via Getty Images)
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.
Antarctic guides walked away from their dream jobs after tourism’s environmental damage became impossible to ignore. “You’d see massive glacier calvings, and you’d just want to cry. But all the guests would be cheering. And you’d be like … ‘Can you not put two and two together?’” Those are the words of a former Antarctic [...]
A new study is challenging one of the most persistent assumptions in space manufacturing: that building advanced composite structures beyond Earth is simply a matter of moving terrestrial production methods into orbit. Research published in npj Advanced Manufacturing examines how two defining features of the space environment—reduced gravity and reduced atmospheric pressure—can alter the manufacture of carbon-fiber-reinforced structures, materials widely regarded as essential for future spacecraft, habitats and large orbital infrastructure.
Carbon-fiber-reinforced polymers, commonly known as CFRPs, combine strong, lightweight carbon fibers with a polymer resin that binds the fibers into a rigid composite. Their exceptional strength-to-weight ratio makes them attractive for launch vehicles and spacecraft, where every kilogram matters. Yet manufacturing these materials is a delicate process. Fibers must be positioned accurately, resin must penetrate the reinforcement evenly, and gases or trapped voids must be removed before the material cures. On Earth, gravity and atmospheric pressure quietly assist—or complicate—each of these steps.
In space, those familiar forces change dramatically. Reduced gravity can alter how liquid resin flows through a carbon-fiber structure, while low pressure can encourage dissolved gases and volatile compounds to expand or escape. Together, these effects may influence impregnation, consolidation, curing and the final mechanical performance of a composite part. The new work by R. Strecker, T. Rieger, A. Tabelander and colleagues focuses on understanding these interactions before manufacturers attempt to produce increasingly complex structures in orbit.
The central issue is void formation. A composite that appears solid can contain microscopic pockets of air or vapor between its fibers. These voids interrupt the transfer of stress through the material and can reduce strength, stiffness and fatigue resistance. During conventional manufacturing on Earth, pressure is often applied to compress the layers and drive out unwanted gases while resin fills the spaces between fibers. In a reduced-gravity environment, however, buoyancy-driven movement is weakened, and the pathways through which bubbles travel may change. A bubble that would rise and escape during terrestrial processing could remain trapped inside the structure.
Pressure reduction introduces another layer of complexity. Lower ambient pressure can help remove volatile substances and trapped gases, but it can also cause dissolved gases in the resin to expand. If the resin is not sufficiently mobile, expanding bubbles may become locked in place as the material cures. The balance between degassing and bubble growth therefore becomes a critical manufacturing parameter. The study’s importance lies in treating pressure and gravity not as isolated variables, but as environmental conditions that can interact throughout the production cycle.
Resin flow is equally important. Carbon-fiber reinforcements are made from tightly packed filaments, creating narrow channels through which resin must travel. On Earth, gravity can influence resin distribution, especially in vertically oriented or large components. In reduced gravity, capillary forces and surface tension become relatively more significant. These forces can help draw resin into small spaces, but they may also create uneven wetting patterns depending on the fiber architecture, resin viscosity and processing orientation. Such changes could affect whether a component cures uniformly from its surface to its interior.
The findings carry implications far beyond laboratory samples. Future space manufacturers may seek to fabricate beams, pressure-vessel elements, antenna supports, solar-array components and repair patches directly in orbit. Producing these parts where they are needed could reduce the need to launch bulky finished structures from Earth. It could also enable designs too large to fit inside a rocket fairing, including trusses and habitation modules assembled gradually in space. But the economic and engineering promise of this approach depends on reliable quality control. A component that looks flawless may still fail if its internal fiber alignment, resin distribution or void content is inconsistent.
The research also highlights why manufacturing hardware designed for Earth cannot automatically be considered space-ready. Pumps, heaters, vacuum systems, molds and curing chambers must all operate under conditions in which heat transfer, fluid movement and gas removal behave differently. Temperature control is particularly important because resin viscosity changes strongly with temperature. A resin that flows readily during terrestrial processing might move more slowly or unevenly in orbit, while excessive heating could accelerate curing before impregnation is complete. Space-based production systems will therefore need carefully coordinated control of pressure, temperature, resin chemistry and processing time.
For engineers, the study provides a foundation for developing manufacturing protocols tailored to reduced-gravity environments. Instead of copying Earth-based workflows, future systems may need staged pressure changes, specialized fiber preforms, modified resin formulations or active bubble-management techniques. Sensors could monitor pressure, temperature and resin flow in real time, allowing automated systems to detect defects before a part is finished. Non-destructive inspection, including imaging and ultrasonic testing, will also be essential for verifying the integrity of components that cannot easily be returned to Earth for analysis.
The broader message is that space manufacturing is not merely an extension of industrial production—it is a new manufacturing regime governed by different physics. Understanding how gravity and pressure reshape the behavior of fluids, gases and composite materials could determine whether orbital fabrication remains a promising experiment or becomes a practical industrial capability. By examining the production of carbon-fiber-reinforced structures under space-relevant conditions, Strecker, Rieger, Tabelander and their colleagues are helping identify the hidden variables that will decide how safely and efficiently humanity can build beyond Earth.
Subject of Research: Effects of reduced gravity and reduced atmospheric pressure on the in-space manufacturing of carbon-fiber-reinforced structures
Article Title: Effects of reduced gravity and reduced atmospheric pressure on in-space manufacturing of carbon-fiber-reinforced structures
Article References: Strecker, R., Rieger, T., Tabelander, A. et al. Effects of reduced gravity and reduced atmospheric pressure on in-space manufacturing of carbon-fiber-reinforced structures. npj Adv. Manuf.3, 26 (2026). https://doi.org/10.1038/s44334-026-00104-w
The Dallas Business Journal reported Monday that the U.S. multinational paper goods company Kimberly-Clark announced "that its researchers identified and advanced patented technology transforming fibers from hesperaloe, a low-water-use plant with pointy leaves that thrives in the southwest region of the country, into material for paper towels." Discovering an alternative to conventional wood fiber "could reshape how the company, and the industry at large, manufactures products," according to article.
And the move comes "amid growing pressure on manufacturers regarding their reliance on wood fibre from freshly felled trees," reports The Telegraph. "Campaigners claim that more than one million trees are cut down every day..."
Unlike trees, hesperaloe can be grown on dry, low-quality farmland unsuitable for most food crops and harvested much more quickly. Kimberly-Clark said it had tested more than 70 potential materials before settling on hesperaloe. Earlier candidates included wheat straw, corn waste, seaweed, algae and chicken feathers. The US consumer goods giant will now develop the fibre at a pilot factory in Yuma, Arizona, working with local growers to determine whether the crop can be cultivated for commercial use in its tissue products. "This represents an exciting moonshot for Kimberly-Clark and the culmination of more than two decades of materials and plant science expertise," said Craig Slavtcheff, who is helping develop the new toilet paper.
However, the company said products made from hesperaloe remained years away from supermarket shelves, with further research needed before the fibre could be produced at the scale required for global manufacturing. The US-based company has invested about $250m (£190m) in the project and filed more than 30 patents linked to the technology.
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."
The "garnet yam" is actually a sweet potato. (Image credit: Sarawuth123 via Getty Images)
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.
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.
A woman sells yams in the market in Abobo in the Ivory Coast on April 22, 2020. (Image credit: ISSOUF SANOGO via Getty Images)
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.
A purple yam, known as ube, from the Philippines. (Image credit: Ezra Acayan / Stringer via Getty Images)
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.
Researchers used quartz from fossilized wood to trace how Europe developed. A polished piece of fossilized wood may look like little more than a decorative stone, yet the quartz inside it can preserve the history of an entire region for hundreds of millions of years. Geologist Dr. Steffen Trümper of the University of Münster and [...]
An international research team has uncovered how LUCA, the last common ancestor of all life on Earth, split into the first two branches of organisms—bacteria and archaea—allowinglife to thrive innew conditions and spread to other biomes.
Scientists from the Institute of Molecular Evolution at Heinrich Heine University Düsseldorf (HHU) led the research, revealing their findings in a recent paper published in Science Advances, investigating these early cells’ metabolisms.
The team discovered that the chemical reactions and energy sources behind these two types of cells told unique stories of separate evolutions, in new work that sheds light on the primordial processes that gave rise to some of Earth’s first free-living cells.
Life on Earth Begins
Roughly four billion years ago, life on Earth emerged as the first cells formed, most likely at hydrothermal vents, before evolving to explore new biomes.
“We would see two very different kinds of cells emerging, pioneer bacteria and pioneer archaea, making their first attempts at life outside the confines of a hydrothermal vent,” said lead author Natalia Mrnjavac, a biologist at the University of Düsseldorf.
The new study investigated protein structures, chemical reactions, and genomes involved in the evolution of these early free-living cells.
“These comparisons are giving us unprecedented insights into the phase of evolution when metabolism catalysed by enzymes was arising from spontaneous reactions catalysed by metals in the Earth’s crust,” said senior author William Martin, a Düsseldorf biologist.
Metabolism and Evolution
Among the new work’s major findings is a consideration of the entire set of 420 chemical reactions involved in metabolism that produce amino acids, RNA bases, and vitamins from the raw materials of hydrogen, ammonia, and carbon dioxide.
These reactions are preserved for modern researchers inside the genetic code, allowing the team to make a surprising discovery: about half of LUCA’s reactions were catalyzed by environmental metals instead of enzymes produced by the organism itself.
“Metals that naturally occur in hydrothermal vents can replace a surprisingly large number of enzymes in metabolism,” said co-author Harun Tüysüz, an inorganic chemist from the Max-Planck-Institut für Kohlenforschung and the IMDEA Materials Institute in Madrid.
In this study, the team reconstructed catalysis evolution from metal-only to a metal-enzyme hybrid present in LUCA, and finally to the divergence of the bacterial and archaeal lineages. This evolution helped life move on from the hydrothermal vents inhabited by the first cells by replacing the inorganic catalysts provided by that environment with new enzymes.
“We can see cases where the ancestors of bacteria and archaea independently evolved structurally distinct enzymes to catalyse the same essential metabolic reaction,” Mrnjavac explained, adding that “such parallel inventions could have paved the way to the independent emergence of free-living bacteria and archaea.”
The Energy for Life on Earth
A primary question involves what supplied the energy driving metabolic reactions in early life on Earth. A compound named ATP is the primary metabolic driver in most organisms today, but it comes from enzymes and is not present in hydrothermal vents. The researchers identified a new energy source in palladium, a natural catalyst used by chemists and also plentiful in hydrothermal vents.
“When we react phosphite, a form of phosphorus that naturally occurs in hydrothermal vents, with organic compounds, we get metabolic phosphorylation reactions overnight in water. Phosphite and palladium replace ATP and enzymes; it’s amazing, and it makes early evolution a lot easier to grasp,” Schlikker said.
Understanding the interconnection between so many reactions presents a significant mathematical challenge. For this reason, the team included not just biologists, but network scientists tasked with ordering the reactions by their complexity, which the researchers hoped would indicate the sequence in which they evolved. Using a machine learning algorithm, the team discovered that a clear order did appear to exist.
“The new data leave only one conclusion,” Martin concluded. “The bacteria and archaeal lineages made the transition to the free-living state independently. Only free-living cells are alive.”
“Let’s call it by name,” Martin added. “We are looking at one origin of the genetic code, but two origins of life.”
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org.
Why it's incredible: The park hosts prehistoric-fossil-bearing rock formations and overlies one of the world's biggest aquifers.
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' remainswere conserved in mudwhen they died.
Uberaba Geopark preserved extinct crocodile relatives among other fossils. (Image credit: Pulsar Imagens via Alamy)
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.]
Opened in 1952, the Volga-Don Canal connects the Volga, which flows into the Caspian Sea, and the Don, which empties into the Sea of Azov (a northern extension of the Black Sea). (Image credit: Gaika102 via Getty Images)
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.
The Volga River supplies roughly 80% of the Caspian Sea's inflow, but huge water demands have decreased its flow. (Image credit: ESA, CC BY-SA 3.0 IGO )
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.
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