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Under the Great Salt Lake playa lies a potentially vast reservoir of pressurized freshwater that has accumulated over thousands of years from mountain-derived snowmelt, according to new research from University of Utah geoscientists. This groundwater occupies the pore spaces in sediments that fill the basin west of the Wasatch Mountains and below a 30-foot-thick salty layer.

For the first time, a study by researchers at Scripps Institution of Oceanography at the University of California, San Diego integrates climate-related damages to the ocean into the social cost of carbon—a measure of economic harm caused by greenhouse gas emissions.

As climate change drives more frequent and severe wildfires across boreal forests in Alaska and northwestern Canada, scientists are asking a critical question: Will these ecosystems continue to store carbon or become a growing source of carbon emissions?

Sometimes to truly study something up close, you have to take a step back. That's what Andrea Donnellan does. An expert in Earth sciences and seismology, she gets much of her data from a bird's-eye view, studying the planet's surface from the air and space, using the data to make discoveries and deepen understanding about earthquakes and other geological processes.

The Indonesian Throughflow carries both warm water and fresh water from the Pacific into the Indian Ocean. As the only low-latitude current that connects the two bodies of water, it plays a key role in ocean circulation and sea surface temperature worldwide.

Publication date: Available online 12 January 2026

Source: Advances in Space Research

Author(s): Zhixi Nie, Zihan Wang, Zhenjie Wang, Ying Xu

Publication date: Available online 12 January 2026

Source: Advances in Space Research

Author(s): Md Sahat Mahmud, Yiping Jiang, Ruirui Liu, Zihong Zhou, Bing Xu

Publication date: Available online 12 January 2026

Source: Advances in Space Research

Author(s): Xingyu Jiang, Peng Shi, Shengping Gong

Publication date: Available online 12 January 2026

Source: Advances in Space Research

Author(s): Hok Sum Fok, Zhongtian Ma

Publication date: Available online 12 January 2026

Source: Advances in Space Research

Author(s): Donghao Song, Hu Ming, Yajing Wang

How much fresh water is in the United States? It's a tough question, since most of the water is underground, accessible at varying depths. In previous decades, it's been answered indirectly from data on rainfall and evaporation. Knowing how much groundwater is available at specific locations is critical to meeting the challenges of water scarcity and contamination.

Global average temperatures in 2025 were the third hottest on record, surpassed only by 2024 and 2023, according to an analysis published by Berkeley Earth, a nonprofit climate research organization.

According to the analysis, last year’s global average temperature was about 1.35°C–1.53°C (2.43°F–2.75°F) greater than the 1850–1900 average. The previous year, 2024, was 1.46°C–1.62°C (2.63°F–2.92°F) above the preindustrial baseline, while 2023 was 1.48°C–1.60°C (2.66°F–2.88°F) above the baseline.

The report’s authors called the exceptional heat of the past 3 years a “warming spike” that may indicate an acceleration in the rate of climate change. “The warming observed from 2023 through 2025 stands out clearly from the long-term trend,” said Robert Rohde, chief scientist at Berkeley Earth, in a statement. 

Such a spike may also indicate that the past warming rate is no longer a reliable predictor of future warming, the authors wrote.

“2023, 2024, and 2025 collectively cause us to rethink” Earth’s warming rate, Rohde said in a press briefing. Whether warming is accelerating or not, Earth’s temperature is rapidly exceeding key thresholds, such as the Paris Agreement limit of 1.5°C (2.7°F), he said.

Scientists say the exceptional warming observed in the past 3 years could be evidence of accelerating warming. Credit: Berkeley Earth, CC BY-NC 4.0

“The overall trends in temperature are very consistent” among international agencies that track global temperature.

The report aligns with an analysis from NOAA’s National Centers for Environmental Information (NCEI) that also concluded that 2025 was the third-hottest year in the global temperature record. NOAA-NCEI calculated that the year was 1.17°C (2.11°F) above the 20th-century global average.

“There are different methodologies for how the global temperature [reports] are created, but the science behind it, the data behind it, by and large, are all shared,” said Karin Gleason, a climate scientist and chief of the monitoring section at NOAA-NCEI.

“The overall trends in temperature are very consistent” among international agencies that track global temperature, she said.

What’s Causing the Spike?

While global average temperatures have been increasing for more than a century, the past 3 years’ warming spike is notably extreme relative to the mostly linear trend of the past 50 years. 

“The magnitude of this recent spike suggests additional factors have amplified recent warming beyond what we would expect from greenhouse gases and natural variability alone.”

“The magnitude of this recent spike suggests additional factors have amplified recent warming beyond what we would expect from greenhouse gases and natural variability alone,” Rohde said.

The report suggested that reductions in cloud cover and changes to atmospheric aerosols, particularly as a result of new regulations on sulfur pollution from ships in 2020, may be partly to blame for the spike. The Hunga Tonga volcanic eruption in 2022 may have also contributed to warming, though further research is needed to fully understand the eruption’s effects, the report stated.

The El Niño-Southern Oscillation (ENSO), a climate phenomenon that affects heat storage in the ocean, contributed to extreme heat in 2023 and 2024 during the El Niño phase, but remained in a weak La Niña condition for much of 2025. Such a condition would typically be expected to slightly cool global temperatures. Without the effect of La Niña, it’s possible 2025 would have been the hottest year ever recorded, Gleason said.

Gleason pointed out that a similar “warming spike” occurred in 2015 and 2016 as a result of a strong El Niño.

Humanity Faces the Heat

According to Berkeley Earth’s report, about 770 million people across the world experienced their local hottest year ever in 2025. The majority of the large population centers affected by this record-breaking heat were in Asia.

No place on Earth recorded the locally coldest year ever.

An estimated 770 million people experienced the locally hottest year ever recorded in 2025. Credit: Berkeley Earth, CC BY-NC 4.0

The report came as estimates from the Rhodium Group, a think tank, showed that the United States’ greenhouse gas emissions increased by 2.4% in 2025 after 2 years of decline. The United States experienced its fourth-hottest year ever recorded in 2025, according to an analysis from Climate Central, a nonprofit climate change research group, and another analysis by NOAA-NCEI. 

The exceptional warming underscores “how essential sustained monitoring is to understanding [climate] changes in real time,” Kristen Sissener, executive director of Berkeley Earth, said in a statement. “Continued investment in high-quality, resilient, and robust open climate data is critical to ensuring that governments, industry, and local communities can respond based on evidence, not assumptions.”

The Berkeley Earth report predicted that global temperature trends in 2026 will be similar to those of 2025, with 2026 expected to be roughly the fourth-warmest year since records began. 

—Grace van Deelen (@gvd.bsky.social), Staff Writer

14 January: This story has been updated to include information from a Berkeley Earth press briefing.

Citation: van Deelen, G. (2026), The past 3 years have been the three hottest on record, Eos, 107, https://doi.org/10.1029/2026EO260031. Published on 14 January 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The storing of the very first heritage cores in Antarctica marks a pivotal moment for the Ice Memory project launched in 2015 by CNRS, IRD, the University of Grenoble-Alpes (France), CNR, Ca' Foscari University of Venice (Italy) and the Paul Scherrer Institute (Switzerland).

In the icy reaches of the Svalbard archipelago, a quiet revolution in marine restoration is underway. Researchers are building a digital twin of the region—an interactive, data-rich simulation designed to help researchers and restoration teams understand how climate change is affecting Arctic coastlines and how its impacts might be reduced.

A study published in Nature shows that many of the world's major river deltas are sinking faster than sea levels are rising, potentially affecting hundreds of millions of people in these regions.

Scientists on Wednesday sealed ancient chunks of glacial ice in a first-of-its-kind sanctuary in Antarctica in the hope of preserving these fast-disappearing records of Earth's past climate for centuries to come.

Lightning has captured people's fascination for millennia. It's embedded in mythology, religion and popular culture. Think of Thor in Norse mythology or Indra in Hinduism.

Devastated by widespread fires, Victoria has declared a state of disaster. More than 500 structures have reportedly been destroyed and 1,000 agricultural properties have been affected. Tragically, there has also been one fatality.

Source: Journal of Geophysical Research: Machine Learning and Computation

The Indonesian Throughflow carries both warm water and fresh water from the Pacific into the Indian Ocean. As the only low-latitude current that connects the two bodies of water, it plays a key role in ocean circulation and sea surface temperature worldwide.

The current is as complex as it is important: The seas surrounding Indonesia are home to deep basins and sills and a hodgepodge of ocean processes that make the Indonesian Throughflow difficult to measure. On-the-ground—or, rather, on-the-sea—observations are scarce as well because such observational systems are expensive and difficult to design and maintain.

Wang et al. combined artificial intelligence (AI) modeling techniques with observing system simulation experiment design concepts. Their method used sea surface height measurements to predict the behavior of this influential current and its individual passages and estimate which strait has the greatest effect on the current’s behavior.

The researchers developed a deep learning model that uses two types of networks to conduct observing system simulation experiments. The first, called a convolutional neural network (CNN), is often used for image classification and, in this case, was used to extract trends from data about the Indonesian Throughflow. The second, called a recurrent neural network (RNN), is most commonly used to sort through sequential data. In this work, the RNN processed the trends identified by the CNN and analyzed their changes over time. The approach proved to be much less computationally costly than running a traditional observing system simulation experiment.

The results recapitulated observed water transport trends and showed that sea surface height is a key predictor of conditions in some of the shallower straits between Indonesian islands. The Maluku Strait emerged as a passage where water conditions have a strong influence on the entire system and thus as a strong candidate for future monitoring efforts, the researchers found. Combining information about the Maluku and Halmahera Straits was even more effective at predicting system-wide conditions. (Journal of Geophysical Research: Machine Learning and Computation, https://doi.org/10.1029/2025JH000808, 2025)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2026), AI sheds light on hard-to-study ocean currents, Eos, 107, https://doi.org/10.1029/2026EO260027. Published on 14 January 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The number of wildland fires burning in the Arctic is on the rise, according to NASA researchers. Moreover, these blazes are burning larger, hotter, and longer than they did in previous decades.