Phys.org: Earth science

To reduce air pollution associated with ocean transport, the International Maritime Organization tightened restrictions on sulfur content in ship fuel, resulting in an 80% reduction in emissions by 2020. That shift created an inadvertent real-world experiment in how man-made aerosols influence cloud formation over the ocean.

When most of us look out at the ocean, we see a mostly flat blue surface stretching to the horizon. It's easy to imagine the sea beneath as calm and largely static—a massive, still abyss far removed from everyday experience.

Wetlands make up only about 6% of the land area but contain about 30% of the terrestrial organic carbon pool. Therefore, CO2 emissions from wetlands are central to the global climate balance. In Denmark, the plan is to flood 140,000 hectares of low-lying land such as bogs and meadows as part of the Green Tripartite Agreement. Flooding such areas will slow down the decomposition of organic material in the soil and keep the CO2 in the soil rather than allowing it to be released to the atmosphere and contribute to the greenhouse effect. At least, that has been the rationale until now.

A new study suggests the world's oxygen-depleted seas may have a chance of returning to higher oxygen concentrations in the centuries to come, despite our increasingly warming climate.

A relatively simple statistical analysis method can more accurately predict the risk of landslides caused by heavy rain, according to a study coordinated by Brazilian researchers affiliated with the Institute of Mathematical and Computer Sciences at the University of São Paulo (ICMC-USP) in São Carlos and the National Institute for Space Research (INPE). The researchers have validated their strategy based on a real event.

In a critical advance for climate resilience, researchers from The Hong Kong University of Science and Technology (HKUST) have developed an AI model that can predict dangerous convective storms—including Black Rainstorms, thunderstorms and extreme heavy rainfall like those that have hit Hong Kong—up to four hours before they strike. This world-first technology, developed in collaboration with national meteorological institutions and powered by satellite data and advanced deep diffusion technology, improves forecast accuracy by over 15% at the 48-kilometer spatial scale compared with existing systems. This breakthrough strengthens the overall accuracy of the national weather forecasting system and promises to transform early warning systems for vulnerable communities across Asia.

A team of NASA scientists deployed on an international mission designed to better understand severe winter storms. The North American Upstream Feature-Resolving and Tropopause Uncertainty Reconnaissance Experiment, or NURTURE, is an airborne campaign that uses a suite of remote sensing instruments to collect atmospheric data on winter weather with a goal of improving the models that feed storm forecasts. This combination of instruments will also serve as a proxy to demonstrate the potential to collect similar observations from space.

Deforestation is having a more devastating effect on the Amazon rainforest than earlier data suggested. While cutting down large swaths of trees destroys vital habitats, it also harms the region's ability to generate its own rainfall. According to a new study published in the journal Nature, the Amazon could reach a tipping point and experience major forest dieback (where large areas of the rainforest dry out and turn into a savanna) sooner than previously thought.

The cycling of water within Earth's interior regulates plate tectonics, volcanism, ocean volume, and climate stability, making it central to the planet's long-term evolution and habitability and a key scientific question. While subducting slabs are known to transport water into the mantle, scientists have long assumed that most hydrous minerals dehydrate at high temperatures, releasing fluids as they descend.

Large-scale melting of the Greenland Ice Sheet is irreversible and happening at a rapid rate, and now a new international study is the first to understand why. A University of Waterloo scientist and a team of international collaborators found that airborne mineral dust and other aerosols are directly connected to how much algae grows on the ice. The algae interfere with albedo, or the reflection of the sun's rays, exacerbating melting. The work is published in the journal Environmental Science & Technology.

A new study using Explainable Artificial Intelligence (XAI) has revealed land-use change—particularly deforestation and unplanned agricultural expansion—is dramatically intensifying heat waves across Africa, with findings that carry direct implications for Australia's warm climate. Although the research focused on Africa, the physical mechanisms behind this amplification are universal.

Mangrove forests play an important role in the global carbon cycle, particularly within the marine carbon system. Growing along tropical and subtropical coastlines, these salt-tolerant trees are among nature's most efficient "blue carbon" sinks, capturing and burying vast amounts of carbon dioxide that would otherwise warm Earth's atmosphere. Much of this carbon is stored in thick, waterlogged soils, where it can remain locked away for centuries, making mangroves a major contributor to long-term coastal carbon sequestration.

Researchers at the University of Kansas have shown the National Severe Storms Laboratory's Warn-on-Forecast System (WoFS) has potential to help weather forecasters issue warnings to emergency managers and the general public well before tornado formation. Their study appears in the peer-reviewed journal Weather and Forecasting.

In its natural state, peatland is one of the largest carbon stores in nature. This is because the soil is so waterlogged and low in oxygen that dead plant material breaks down very slowly. The plants do not fully decompose but instead accumulate over thousands of years, forming thick layers of peat. When a peatland is drained for agricultural use, the water level drops and oxygen enters the peat layer. Microorganisms can then break down the old plant material much faster, releasing carbon that has been stored for many years as the greenhouse gas carbon dioxide (CO₂).

The U.S. Geological Survey (USGS) crowdsourcing platform Did You Feel It? (DYFI) rapidly transforms people's earthquake shaking intensity experiences into detailed maps of damage extent. While the tool's reach is global, language and technology barriers prevent participation in certain areas, according to a USGS and University of Michigan Engineering study published in Seismological Research Letters.

Mass extinctions are extremely catastrophic events on Earth. Throughout Earth's evolutionary history, numerous mass extinctions have occurred, with five major mass extinctions being particularly representative. These extinctions have reshaped the course of life's evolution on Earth. In addition to the five major mass extinctions, many frequent, lower-order extinctions have also taken place on Earth, such as the Norian–Rhaetian Extinction during the Triassic. Regarding the triggering mechanisms of extinctions, the five major events have been relatively well studied. However, the triggering mechanisms of the frequent lower-order extinctions remain unclear.

Narrow bands of ocean covering just over one-third of the world's seas are responsible for absorbing nearly three-quarters of the carbon dioxide that oceans pull from the atmosphere, new research shows. The study, published in Nature Climate Change, reveals ocean fronts play a far larger role in regulating Earth's carbon cycle than previously understood.

The Nature Conservancy in Nevada (TNC in Nevada), DRI, and the University of Wisconsin—Madison (UW-Madison) have developed the Nevada GDE Water Needs Explorer Tool. This new online resource helps land and water managers understand how groundwater supports groundwater-dependent ecosystems (GDEs) and how changes in water levels can affect them.

In lush South Florida, trees and bushes grow all year round. And that means yard waste and dead trees never stop piling up. But leaving them in a landfill is a climate-warming issue. Two South Florida governments think they have a new solution—light it on fire, but in a planet-friendly way.

Water is everywhere, from the snowpack in the mountains to the tap in our kitchens. But while we often think about rainfall and snow as the main drivers of our water supply, it turns out that something we rarely see has just as much influence: the underground structure of the landscape itself.