Science word of the day: Autotroph

Pronunciation: AW'-tuh-trohf

What it means: Autotrophs are organisms that can feed themselves with inorganic substances such as light (for plants) or methane (certain microbes). Autotrophs were the first single-celled life-forms to colonize the planet, thriving on chemicals bubbling up from the subsurface at deep-sea vents or figuring out how to harness the sun for energy. Heterotrophs (like you, me and all fungi), arrived on the scene later to feast on these DIY-ers.

How to use it in a sentence: Stromatolites, microbial mats built by cyanobacteria, are autotrophs that thrived in ancient shallow seas.

Can you crack our science word of the day puzzle, Chain Word?

This year's El Niño will almost certainly become the strongest ever recorded, an analysis by a prominent climate researcher has warned. Though other scientists have cautioned that it's still too early to say what it will unleash.

Dynamical models now assign a 90% chance of the 2026-2027 El Niño being an all-time record event, sending temperatures in the Pacific Ocean up to around 3.6 degrees Celsius (6.5 degrees Fahrenheit) above average, according to an analysis by Zeke Hausfather, a research scientist at Berkeley Earth and an author of the Intergovernmental Panel on Climate Change's Seventh Assessment Report.

As the warm phase of a multiyear natural climate pattern, the El Niño could bring unprecedented temperature extremes to an already-warming world. The natural climate pattern is infamous for boosting global temperatures and fueling disruptive weather events such as floods and droughts.

A strong El Niño doesn't guarantee more severe weather impacts. The current El Niño models are also imperfect predictions of what's to come, and we won't know the true nature of this El Niño event until it peaks, likely later this year. However, forecasters have been warning of potentially supercharged El Niño conditions for months, and as more data emerges, there are more reasons to prepare.

According to projections by the World Meteorological Organization, the current El Niño — officially declared on June 11 — is on track to rapidly develop into a "strong" event between July and September. The National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center now predicts a more than 80% likelihood of very strong El Niño conditions taking hold by the end of the year, ranking this El Niño event among the largest in the historical record.

"These are striking forecasts," Emily Black, a professor of terrestrial processes and climate at the University of Reading and a senior scientist at the National Centre for Atmospheric Science in the U.K., told Live Science in an email. "El Niño forecasts always come with uncertainty, but the level of agreement between models at this time of year, combined with the observed warming already underway in the tropical Pacific, means this should be taken very seriously."

"The important point is that a very strong El Niño would substantially shift the odds of damaging weather in many parts of the world, particularly in the Global South — with severe impact on livelihoods," Black added.

The International Rescue Committee, a humanitarian organization, has warned that the intense El Niño conditions threaten to unleash severe flooding and drought across East Africa and Asia, hitting some of the most vulnerable communities, Al Jazeera reported Tuesday (July 14).

During El Niño, warmer waters gather east of the equatorial Pacific, forcing the jet stream south. In the U.S., this typically brings warmer, drier conditions to the Northeast, while the Gulf Coast and Southeast experience an increased risk of flooding. Globally, the net result of the warmer waters is more heat in the atmosphere, on top of the temperature rise from human-driven global warming.

"El Niño is a natural climate phenomenon, but it is now happening against the backdrop of a much warmer planet," Black said. "That matters because a strong El Niño releases heat and energy into an already warmed world."

"This does not mean every impact can be attributed simply to El Niño or simply to climate change," Black added. "The two interact. El Niño can load the dice towards drought in some regions, flooding in others, marine heatwaves, disrupted monsoons and unusually high global temperatures. Climate change makes many heat extremes more severe and can intensify heavy rainfall because a warmer atmosphere can hold more moisture."

The last El Niño event occurred between 2023 and 2024. Both years broke temperature records, with 2024 becoming the hottest on record and the first to breach the 1.5-degree- Celsius (2.7 degrees Fahrenheit) warming limit set by the 2016 Paris Agreement. The current El Niño is forecast to be more intense than the one in 2023 and 2024, with the projected "very strong" status putting it in a different class of severity.

The strongest El Niño in history?

Hausfather's analysis reports that there's around a 90% chance that the current El Niño will be the strongest ever recorded, with data from multimodel forecasts suggesting that it may obliterate the previous record.

"With the July runs now in from 667 ensemble members across 14 different seasonal forecast models, it looks like this year's El Niño is not only very likely to be the strongest event since reliable records began ‪—‬ it may end up the strongest by a truly mind-blowing margin," Hausfather wrote in The Climate Brink Substack post published Monday (July 13).

NOAA recognizes El Niño conditions when the eastern tropical Pacific Ocean is at least 0.5 C (0.9 F) warmer than the historical average, while wind, surface pressure and rainfall in the region are also consistent with El Niño conditions. The El Niño is then categorized as weak, moderate, strong or very strong. A very strong El Niño (above 2 C, or 3.6 F, warmer than the historical average) is often nicknamed a "super" El Niño, though it's not a scientific term.

The July models suggest that temperatures will likely sail past 2 C above average in the coming months and could potentially even exceed 3.5 C (6.3 F) above average by the end of the year. This is based on newly introduced sea surface temperature forecasts that account for rising background temperatures that can inflate El Niño warming figures. In the traditional and most widely used indices, the temperature-anomaly forecasts cluster closer to 4 C (7.2 F), with some even exceeding 4 C.

In The Climate Brink Substack, Hausfather noted that the multimodel median for the event's peak is currently forecast at 3.6 C (6.5 F), or around 0.8 C (1.4 F) hotter than the prior record holder (2.75 C, set in the 2015-2016 El Niño event). Hausfather wrote that around 91% of ensemble members (individual computer models) have this El Niño exceeding the 2015-2016 record at their peak — around 77% likelihood in the newly introduced indices.

However, Black stressed that the models are still estimates, and not guarantees.

"It is certainly plausible that this could become a record-breaking El Niño, and the latest forecasts make that a real possibility rather than a remote one," Black said. "However, I would still be cautious about treating any probability estimate as a certainty."

"There are two reasons for caution," she added. "First, this event has not peaked yet, and El Niño events usually reach their maximum strength later in the year. Second, 'strongest ever recorded' depends on the index, dataset and baseline used."

"Impacts are what matter"

The most severe El Niño events have left a trail of devastation in their wake. For example, the 2015-2016 El Niño saw a record-breaking hurricane season in the central North Pacific, severe drought in the Caribbean and Ethiopia, and, of course, abnormally hot global temperatures, according to NOAA's Climate.gov. If the forecasts pan out, the current El Niño will match or exceed the 2015-2016 event, as well as an even more infamous super El Niño that occurred between 1877 and 1878, long before modern recordkeeping of El Niño began in 1950.

The 1877-1878 event likely fueled an extreme drought that fed into the 1876-1878 global famine, which ultimately killed more than 50 million people — making it among the worst humanitarian crises in history. However, the disaster was far from just an environmental one, with extractive colonial agricultural policies helping to create conditions for a massive humanitarian crisis. Nonetheless, the famine highlights what can happen when environmental and socioeconomic factors converge.

Even though the world has changed a lot since the 19th century, experts have said a super El Niño could still cause severe shocks to our food systems. This is especially true at a time when researchers say food insecurity is not just confined to low-income countries and that climate change is already pushing agricultural systems to the brink.

The El Niño-Southern Oscillation cycle triggers a warm El Niño and then a cold La Niña roughly every two to seven years, with each phase typically lasting around nine to 12 months. Carbon Brief has predicted that 2026 is likely to be the second-warmest year on record, with the intensifying El Niño increasing the likelihood that 2027 will be the warmest year ever recorded.

The strength of an El Niño event does not necessarily correspond to the size of its influence or impact, according to the Climate Prediction Center. More severe events typically, but not always, increase the certainty of expected impacts. Black believes the impact of an El Niño event is more important than where it ranks in the observational record.

"Records are compelling, but impacts are what matter," Black said. "Even if it falls just short of a record, a very strong El Niño can still have serious consequences. Finally, these forecasts are concerning, but they are also useful: they give societies time to anticipate possible impacts and act before the worst effects are felt."

Heaven Lake is a crater lake at the top of Mount Changbaishan (also called Changbai Mountain) — a colossal, dormant volcano on the border between China and North Korea that formed through successive eruptions over the past 2.6 million years.

Known in China as Tianchi, the lake is the highest and largest crater lake in Northeast Asia, according to UNESCO. It is also the deepest lake in China, according to a study published in March. The lake sits at an elevation of around 7,200 feet (2,200 meters), covers roughly 3.6 square miles (9.2 square kilometers), and has a maximum depth of 1,224 feet (373 m), according to the study.

Heaven Lake is surrounded by 16 peaks that belong to Mount Changbaishan. The lake fills a caldera created by past eruptions, the biggest of which was the "millennium eruption" that took place in A.D. 946 and remains one of the largest eruptions in modern history.

Water started to pool on Mount Changbaishan's summit after the prehistoric Tianwenfeng eruption, which scientists dated to between 70,000 and 40,000 years ago. Heaven Lake has periodically emptied and refilled since then due to precipitation, snowmelt, and an active geothermal system beneath the volcano that forces water up through fault lines.

Although hundreds of reports in the early 2000s claimed there was a creature with a head shaped like that of a horse living in the water, scientists have repeatedly said they are skeptical that any large creature could survive in Heaven Lake.

Mount Changbaishan is one of the best-preserved stratovolcanoes from the past several million years, according to UNESCO. Stratovolcanoes, also known as composite volcanoes, are volcanic mountains built from alternating layers of solidified lava, volcanic ash and rocky debris. Mount Changbaishan is an "open-air classroom for volcanism" because it recorded the different stages of multiple eruptions in astounding detail.

In North Korea, Mount Changbaishan is known as Mount Paektu or Paeku Mountain, meaning "white-topped mountain." The volcano's Chinese name means "forever white mountain."

China, North Korea and South Korea have clashed over the volcano in the past, as the mountain holds cultural and geopolitical significance for the three countries. Two border treaties between China and North Korea in 1962 and 1964 divided the volcano and Heaven Lake roughly down the middle, with North Korea securing 54.5% of the lake.

In the 2000s, China moved to develop the region around the volcano, opening the Mount Changbai Airport and the Mount Changbai Eastern Railroad to connect the region with the rest of the country.

A geological park surrounding the Chinese site of the volcano was officially designated a UNESCO Global Geopark in 2024.

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

A large pit discovered by an amateur astronomer on Google Maps in 2024 is actually a 390 million-year-old meteor impact crater, scientists have confirmed.

Joël Lapointe was planning a camping trail through Quebec's Côte-Nord region when he stumbled upon a large indentation in the terrain, CBC reported at the time. The pit, centered around Lake Marsal, was about 25 kilometers (15.5 miles) in diameter and a near-perfect ring — it didn't seem like a normal ditch. Lapointe eventually got in touch with French geophysicist Pierre Rochette, who said that the surrounding topography was "very suggestive" of an impact crater.

Initial testing of samples retrieved from the site contained a mineral called zircon often formed during meteor impacts. However, zircon's presence alone was not enough to prove the crater's extraterrestrial origin story. So a team of scientists had visited the pit in person.

"One of the key things we look for is evidence for shock metamorphism, which can only occur due to the immense pressures created by asteroid or cometary impacts — or nuclear explosions," Gordon Osinski, a professor of planetary geology at Western University, told Live Science in an email. "Most of these features are microscopic, so you can only confirm in the lab with samples."

But there is one feature Osinski said can be seen with the naked eye: grooves or lines in the rock's surface called shatter cones, which are caused by shockwaves passing through the ground.

In October 2025, Osinski and a team of geologists visited the site to investigate whether any of these features were present. "This was one of the most arduous expeditions I’ve ever done — and I’ve done 25 expeditions to the Arctic and 6 continents," he said. "The terrain was incredibly rough and rugged, plus [there were] lots of bugs."

But they eventually found what they were looking for — shatter cones. They also discovered big cliffs of impact melt rock, created by the intense temperatures and pressures produced by a meteor impact. "You can melt literally tens of cubic kilometres of the Earth's crust when you get a big enough asteroid hitting," Osinski told CBC.

Taking samples from the rocks, the team dated the crater at 390 million years old.

Osinski, who runs a website called Impact Earth dedicated to verifying meteor impact sites, is used to getting emails about strange looking satellite images. "I get lots of messages from the public thinking they have found a crater and 99/100 turn out not to be the case," he told Live Science. "This is one of those rare examples that shows this is possible."

So far, we know of roughly 200 impact craters on Earth, 31 of which have been found in Canada. "Typically about 1 or 2 craters are discovered per year, but these are typically less than 5-10 km [3 to 6 miles] in size," Osinski said. "[A crater of this size] is pretty rare."

The last meteor crater confirmed in Canada was in 2010.

After the new investigation confirmed the pit was punched out by a meteor impact, Osinski, Rochette and their team named it Uhaachatik Crater following discussions with the Ekuanitshit Innu council, a council representing the indigenous people in the area. The researchers will present their work at the Annual Meeting of the Meteorological Society in Germany next month.

Speaking to Radio-Canada, Lapointe said that he was very happy to hear his discovery had been confirmed as a genuine meteor crater. "It's not every day that an ordinary citizen finds a 390-million-year-old crater," he said. “I encourage everyone to not ignore intuition or an observation, even if it isn’t part of your field of expertise.”

Osinski and the team will continue their work on the collected samples to learn more about the impact site. "Any crater discovered offers us insight into how craters form and the effects that they can have on Earth’s geology, biology, and climate," he told Live Science.