Phys.org: Earth science

The processes that form continental crust from the denser basaltic rocks of the upper mantle may make the lower lithosphere denser than the underlying mantle. One theory holds that the lower lithosphere splits away and sinks into the mantle in a process called foundering. Conclusive evidence of foundering, however, has been hard to come by.

Carbon dioxide in the atmosphere is increasing at rates that are incompatible with staying below 1.5 degrees Celsius (2.7 degrees Fahrenheit) of global warming, a Met Office study warns.

Extreme climate events endanger groundwater quality and stability when rain water evades natural purification processes in the soil. This was demonstrated in long-term groundwater analyses using new analytical methods, as described in a recent study in Nature Communications. As billions of people rely on sufficient and clean groundwater for drinking, understanding the impacts of climate extremes on future water security is crucial.

Directly measuring soil carbon rather than relying on predictive models can provide hard evidence of how much carbon is being stored, allowing for better assessments of confidence in carbon markets for croplands, according to a study co-authored by Yale School of the Environment scientists and recently published in Environmental Research Letters.

The Arctic is heating up particularly fast as a result of global warming—with serious consequences. The widespread permafrost in this region, where soils currently store twice as much carbon as the atmosphere, is thawing. Scientists are using increasingly detailed climate models to investigate what this means for the global climate and which striking feedbacks need to be taken into account.

A new study finds that climate change may have a range of contrasting effects on coastal forests, both slowing and enabling growth in areas where sea levels are rising and storms are more common.

On the basis of current carbon emissions rates and climate policies, average global temperatures are projected to increase to 2.9°C above preindustrial averages by the end of the century. Such an increase would severely strain global agriculture, making large tracts of current production areas unsuitable for crops and livestock. At the same time, the Food and Agriculture Organization of the United Nations estimates that food production needs to increase by 70% to keep pace with population growth.

In a recently published paper, NASA scientists use nearly 20 years of observations to show that the global water cycle is shifting in unprecedented ways. The majority of those shifts are driven by activities such as agriculture and could have impacts on ecosystems and water management, especially in certain regions.

Research co-led by the University of Maryland reveals that drought and increased temperatures in a CO2-rich climate can dramatically alter how grasslands use and move water.

Increasingly common since 1980, persistent multi-year droughts will continue to advance with the warming climate, warns a study from the Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), with Professor Francesca Pellicciotti from the Institute of Science and Technology Austria (ISTA) participating.

Approximately 66 million years ago, the Chicxulub asteroid, estimated to be 10–15 kilometers in diameter, struck the Yucatán Peninsula (in current-day Mexico), creating a 200-kilometer-wide impact crater. This impact triggered a chain reaction of destructive events, including a rapid climate change that eventually led to the extinction of the non-avian dinosaurs and, in total, about 75% of species on Earth.

Dichlorodiphenyltrichloroethane (DDT) soil pollution is still a major problem in many parts of the world. Researchers at Chalmers University of Technology, Sweden, have developed a new method to manage ecological risks from the toxin by binding it with biochar. When they mixed biochar into contaminated soil at a former tree nursery, DDT uptake by earthworms in the soil was halved. This method may enable the growing of certain crops on land that is currently considered unusable due to environmental risks.

Permafrost thaw poses multiple risks to local Arctic communities, their livelihoods, infrastructure and environment. A transdisciplinary study led by Umeå University and others has identified key risks across four Arctic regions. This allows communities to adapt and make informed decisions.

The synchronization of data from two natural climate archives—a speleothem from the Herbstlabyrinth Cave in Hesse (Germany) and ice cores from Greenland—offers new insights into the chronology of abrupt climate changes in Central Europe.

As climate change drives increasingly severe hurricanes, U.S. coastal communities are bearing the brunt of mounting losses. With regulations failing to curb the damage, homeowners have become the front line of defense—but their efforts often fall short, a recent study reveals.

Ecological warning lights have blinked on across the Arctic over the last 40 years, according to new research, and many of the fastest-changing areas are clustered in Siberia, the Canadian Northwest Territories, and Alaska.

The Little Ice Age was a period of significant cooling from the early 14th to mid-19th centuries, which saw mean temperatures across the northern hemisphere drop by up to 2°C and the advancement of glaciers.

McGill University researchers have discovered that changes in clouds are slightly mitigating global warming. While greenhouse gases continue to cause temperatures to rise, a reduction in low-cloud cover over land has brought about a modest reduction of the amount of heat being trapped close to ground level.

Methane from the destroyed Nord Stream pipelines spread over a large part of the southern Baltic Sea and remained for several months. This is according to a study by researchers from the University of Gothenburg and the Voice of the Ocean research foundation.

With the increase in climate change, global precipitation estimates have become a necessity for predicting water-related disasters like floods and droughts, as well as for managing water resources. The most accurate data that can be used for these predictions are ground rain gauge observations, but it is often challenging due to limited locations and sparse rain gauge data.