Phys.org: Earth science

Carbon dioxide levels in the atmosphere vary naturally between ice ages and interglacial periods. A new study by researchers at the University of Gothenburg shows that an unexpectedly large proportion of carbon dioxide emissions after the ice age may have come from thawing permafrost.

Some 14,000 years ago, algal blooms in the Southern Ocean helped to massively reduce the global carbon dioxide content of the atmosphere—as has now been revealed by new analyses of ancient DNA published by a team from the Alfred Wegener Institute (AWI) in the journal Nature Geoscience. In the ocean around the Antarctic continent, these algal blooms had a significant impact on global carbon dynamics. The current and expected future decline in sea ice in this region now poses a serious threat to these algae, which could incur global consequences.

Solid as they are, rocks are not static materials with constant properties. Even small loads are enough to alter their mechanical properties; their reaction to being deformed is a loss of stiffness. Rocks which have been damaged in such a way are then less able to withstand loads, such as gravity or tectonic stresses. This phenomenon is therefore of relevance for understanding the occurrence of material failure, as in landslides or earthquakes.

Materials scientists at the University of California San Diego have performed powerful laser shock experiments on a perovskite mineral to better understand the geophysical processes in Earth's deep interior and the mechanisms behind earthquakes deep within the planet.

About 71% of Earth's surface is covered by the vast oceans. When winds blow over the sea surface, they transfer energy to the water, creating waves. Some of these waves, under the force of strong winds, break and produce tiny airborne droplets that become sea spray aerosols. This process happens across all oceans and is one of the world's largest sources of aerosols. Despite decades of research, scientists still do not fully understand the impact on the planet's climate, especially how much they contribute to particles that form clouds, known as cloud condensation nuclei.

A research team from the Aerospace Information Research Institute of the Chinese Academy of Sciences has developed a new method for evaluating urban sustainability, leveraging high-resolution data from the SDGSAT-1 satellite, according to a study published in Remote Sensing of Environment.

A team of geoscientists has identified a subtle but powerful force driving mountain building and compression of Earth's crust in Japan and neighboring regions. The so-called same-dip double subduction (SDDS) in nearby oceanic trenches has effects reaching hundreds and thousands of kilometers away from the zone of subduction.

Under high-emission scenarios, the Atlantic meridional overturning circulation (AMOC), a key system of ocean currents that also includes the Gulf Stream, could shut down after the year 2100. This is the conclusion of a new study, with contributions by the Potsdam Institute for Climate Impact Research (PIK). The shutdown would cut the ocean's northward heat supply, causing summer drying and severe winter extremes in northwestern Europe and shifts in tropical rainfall belts.

For decades, the Tijuana River has carried millions of gallons of untreated sewage and industrial waste across the U.S.-Mexico border. The river passes through San Diego's South Bay region before emptying into the ocean, recently leading to more than 1,300 consecutive days of beach closures and water quality concerns.

Clouds are important for Earth's energy balance because they interact with radiation in different ways. On one hand, low clouds reflect incoming solar radiation and thus cool Earth through a property known as albedo. On the other hand, clouds mainly at high altitudes prevent thermal radiation from escaping into space, which has a warming effect. Overall, the cooling effect currently dominates.

A more thorough way to estimate how much the world's boreal-Arctic wetlands and lakes contribute to current and future harmful methane emissions has been developed in part by University of Alberta researchers.

Humanity and the environment's adaptation to climate change is dependent on water, but projecting how water resources will be impacted in the future is difficult.

How Earth's atmosphere transformed from oxygen-poor to oxygen-rich over a span of about two billion years has been revealed by an international team of researchers.

An international team of scientists led by microbiologists Marc Mussmann and Alexander Loy from the University of Vienna has discovered a new microbial metabolism: so-called MISO bacteria "breathe" iron minerals by oxidizing toxic sulfide.

Supercell thunderstorms are among the most impactful weather events in Europe. They typically occur in summer and are characterized by a rotating updraft of warm, humid air that brings strong winds, large hail and heavy rain. The impact is significant and often leads to property damage, agricultural losses, traffic chaos and even threats to human safety.

A new study led by researchers from the Aerospace Information Research Institute (AIR) of the Chinese Academy of Sciences has for the first time mapped the long-term, large-scale transport pathways of PM2.5 pollution across China spanning from 2000 to 2021, providing scientific support for refining national air quality management strategies.

When water is below normal levels in Latin America, it's not just farmers and consumers who suffer. A new study finds that air pollution spikes, and thousands of people die prematurely as a result.

On August 5, a cloudburst near the Kheer Ganga river triggered a flash flood that tore through Dharali, a village in the Indian Himalayas. Within minutes, the river swelled with water, mud and debris, sweeping away homes, roads and lives.

Research by the University of Southampton and University of East Anglia (UEA) shows a major shift in South Pacific climate conditions—beginning around 1,000 years ago—that may have pushed people to settle further east and move away from increasingly drier conditions in the west.

Microplastics and nanoplastics are not only polluting our oceans, rivers and fields, but also our forests, according to geoscientists at TU Darmstadt. Their research is published in Communications Earth & Environment.