Phys.org: Earth science

Thanks to upstream diversions and climate change, Utah's Great Salt Lake has shrunk by 70% since 1989, exposing about 800 square miles of playa and mudflats—along with numerous curiosities. While a potential environmental catastrophe, the lake's dewatering presents numerous research opportunities for University of Utah geoscientists, including several who are looking to characterize the extent, characteristics, chemistry and flow of a mysterious, mostly freshwater aquifer under the playa.

The Amazon rainforest is famous for storing massive amounts of carbon in its trees and soils, helping regulate the global climate. Yet a paper published in New Phytologist shows that one of South America's largest carbon-storing ecosystems exists in an often-overlooked grassy savanna: the Cerrado in Brazil.

Before rain begins to fall, scientists and engineers can predict where a storm might cause flooding thanks to advanced modeling and digital simulations that help guide billion-dollar decisions involving infrastructure design, emergency response, land-use planning, insurance, agriculture, water quality, and public safety.

Artificial intelligence is rapidly transforming weather prediction, enabling forecasts that once required hours of supercomputing time to run in just minutes. But as AI tools play an expanding role in high-stakes hazard modeling, researchers at Rice University say an essential question remains: Do AI-generated storms behave realistically?

Two new studies conclude that stabilizing long-term climate risks will require sustained net-negative carbon dioxide (CO₂) emissions for centuries. Approaching the problem from distinct perspectives—legal and technological feasibility on the one hand, and economic optimization under uncertainty on the other—the research converges on a consistent message: reaching net zero is not enough.

From the rice paddies of South Asia to the wheat fields of northern China, summer monsoon rains sustain the livelihoods of billions. Yet these vital rains fluctuate dramatically from decade to decade—a variability that has long puzzled climate scientists.

Forests were growing on the now-submerged landmass of Doggerland thousands of years earlier than previously believed, according to a major new sedimentary ancient DNA (sedaDNA) study led by the University of Warwick. The findings suggest that Doggerland may have provided a surprisingly hospitable refuge for plants, animals, and potentially humans, thousands of years before forests became widespread across Britain and northern Europe.

The tidal environment of mangrove forests serves as nurseries for many fish species. Researchers at the University of Gothenburg have measured carbon dioxide and oxygen levels in 23 of the world's mangrove areas. The study, published in the journal Geophysical Research Letters, sends out a warning that these ecosystems are increasingly threatened as sea temperatures continue to rise.

A research team led by Professor Jonghun Kam from POSTECH (Pohang University of Science and Technology) has revealed that typhoons are a critical factor in mitigating global droughts by simulating a scenario where typhoon-induced precipitation is removed. The study, published in Geophysical Research Letters, delivers the message that "imagining a world without typhoons is the starting point for understanding future droughts."

Californians have long dealt with wildfire smoke as a seasonal fact of life, but those fires have become more intense and frequent, raising the profile of wildfire smoke as a public health issue. Now, a study led by researchers at UC San Diego's Scripps Institution of Oceanography finds that the time between multi-day smoke events is shrinking—leaving communities with less time to recover before smoke returns.

By 2050, up to half the world's urban population will face water scarcity. A new model of water supply, demand, and policies in a drought-prone city of 7 million in India shows how policies could prevent the poor from bearing the heaviest burden.

An article published recently in Nature Geoscience warns that Antarctica's ice masses have begun to experience a process scientists call "Greenlandification." The term refers to the unprecedented retreat of Greenland's outlet glaciers and longer surface melt seasons.

Brazilian researchers have developed an index that can measure the health of mangrove soils at different stages. When applied to degraded, restored, and preserved areas, the index revealed that healthy mangroves, including recovered ones, provide ecosystem services at nearly maximum capacity. In contrast, deforested mangroves have only a small fraction of this potential.

Alaska's glacial lakes are growing faster than in previous decades. They expanded by more than 150 square kilometers between 2018 and 2024, and could eventually grow to more than four times their current size as glaciers retreat, according to a new study published in the journal PNAS.

A new study led by researchers at the Earth-Life Science Institute (ELSI) at Institute of Science Tokyo challenges a long-standing assumption about Earth's most extreme ice ages. Using numerical geochemical models, the team showed that chemical weathering may have continued beneath thick continental ice sheets during the snowball Earth event, consuming atmospheric carbon dioxide (CO₂) and potentially prolonging global glaciation.

In some parts of the deep ocean, it can look like it's snowing. This "marine snow" is the dust and detritus that organisms slough off as they die and decompose. Marine snow can fall several kilometers to the deepest parts of the ocean, where the particles are buried in the seafloor for millennia.

There is growing interest in the scientific community and private sector in biological approaches to marine carbon dioxide removal—strategies designed to enhance the ocean's natural ability to absorb carbon from the atmosphere. However, a study led by Megan Sullivan, a postdoctoral researcher in the University of Rhode Island's Graduate School of Oceanography (GSO), suggests that some proposals may overlook an important factor.

Changes in the Gulf Stream, a strong ocean current in the Atlantic, could serve as an early warning of the imminent collapse of the Atlantic Meridional Overturning Circulation (AMOC). The AMOC is a massive system of ocean currents that acts as a conveyor belt, moving heat from the tropics to the North Atlantic. The part of this system that flows along the east coast of the United States and then east toward Europe is the Gulf Stream. Scientists are concerned that if the AMOC were to collapse, it could trigger drastic climate shifts, especially in Europe, where temperatures could plummet.

How is carbon metabolized and processed in different ecosystems? In a study published in the journal Communications Earth & Environment, researchers led by Joely Maak, the study's first author and researcher in the Cluster of Excellence "The Ocean Floor—Earth's Uncharted Interface," examined the carbon cycle in a unique marine ecosystem.

When Saharan dust reaches the UK and Europe, as a huge country-sized cloud did over the past few days, it can transform the sky. Tiny particles drifting in the atmosphere scatter blue light while allowing reds and oranges to reach us intact, producing beautiful sunsets.