Climate

This year may already be on track to be the second hottest on record, after 2024. Floods and tornadoes are wracking wide swathes of the United States. And more wild weather is expected to be on the horizon.

But the federal government’s ability — and long-standing charge — to warn the nation about the future impacts of climate change is in jeopardy. On April 28, the Trump administration abruptly dismissed the hundreds of U.S. scientists working on the sixth National Climate Assessment, a congressionally mandated interagency report. The latest report was expected to be released in 2028, but now its future is in doubt. And that could greatly hobble the nation’s ability to prepare for future climate-related extreme events. More

Warming temperatures may cause methane emissions from wetlands to rise — by helping methane-producing bacteria thrive. Higher temperatures favor the activity of wetland soil microbes that produce the potent greenhouse gas, at the expense of other microbes that can consume it, researchers report April 23 in Science Advances.

The scientists, led by microbiologist Jaehyun Lee of the Korea Institute of Science and Technology in Seoul, conducted a summer field study in coastal wetlands near the Chesapeake Bay, analyzing soil conditions in a set of marshy plots with differing environmental conditions. The findings may offer clues to a puzzling and worrisome spike in wetland emissions of methane over the last decade. More

Earth’s landmasses are holding onto a lot less water than they used to — and this loss is not just due to melting ice sheets. Terrestrial water storage, which includes water in underground aquifers, lakes, rivers and the tiny pore spaces within soil, declined by trillions of metric tons in the early 21st century, researchers report in the March 28 Science.

This sharp decrease in freshwater stores is driven by rising temperatures on land and in the oceans, which in turn are linked to an increased global incidence of drought. And given the projected warming of the planet, this trend isn’t likely to change any time soon, say geophysicist Ki-Weon Seo of Seoul National University and colleagues. More

Beneath the great, white expanse of the Antarctic Ice Sheet, a mysterious realm of streams and lakes lies out of sight. Much about this hidden water world remains poorly understood. But a new study suggests that if scientists continue to overlook it, they might greatly underestimate global sea level rise.

Factoring this subglacial water into computer simulations could boost projections of sea level rise over the next two centuries by about two meters, researchers report April 7 in Nature Communications. For context, scientists estimate that climate warming has raised sea levels by about 0.2 meters over the last century. More

The Arabian Desert, today the largest expanse of windswept sand dunes on Earth, experienced recurring periods of humidity millions of years ago, researchers report April 9 in Nature. The study may explain how mammals at that time survived the trek across what is now a vast and barren landscape.

The findings come from mineral formations deep inside caves beneath the Arabian Peninsula. These speleothems — stalagmites and stalactites, formed by dripping rainwater — provide evidence that the region underwent repeated humid periods stretching back nearly 8 million years. The scientists used uranium dating to precisely determine the ages of speleothem samples, offering one of the oldest climate records for the region. More

Earth’s average temperature is continuing to tick inexorably upward as the world’s nations stall at reducing their atmosphere-warming emissions. In the face of that grim future, strategies to try to turn down the planet’s thermostat are gaining traction. One strategy in particular — solar geoengineering, which aims to cool the planet by reflecting solar radiation back into space — may be having a moment in the sun.

Depending on whom you ask, it’s potentially highly dangerous, highly promising or highly uncertain. There aren’t any real guidelines. But, with the future of emissions restrictions also highly uncertain, some researchers say solar geoengineering needs to be on the table. More

A new cement-making process could shift production from being a carbon source to a carbon sink, creating a carbon-negative version of the building material, researchers report March 18 in Advanced Sustainable Systems. This process might also be adaptable to producing a variety of carbon-stashing products such as paint, plaster and concrete.

Cement production is a huge contributor to global carbon dioxide emissions, responsible for about 8 percent of total CO2 emissions, making it the fourth-largest emitter in the world. Much of that carbon comes from mining for the raw materials for concrete in mountains, riverbeds and the ocean floor. More