Phys.org: Earth science

La Niña—a climate phenomenon characterized by unusually cool sea surface temperatures in the central and eastern tropical Pacific Ocean—can persist for multiple years, exerting significant climate impacts worldwide. In recent decades, such prolonged La Niña events have grown more frequent. However, the mechanisms that sustain these multiyear cooling episodes have remained unclear.

A 66 million-year-old mystery behind how our planet transformed from a tropical greenhouse to the ice-capped world of today has been unraveled by scientists. Their new study has revealed that Earth's massive drop in temperature after the dinosaurs went extinct could have been caused by a large decrease in calcium levels in the ocean.

The asteroid that struck the Earth 66 million years ago devastated life across the planet, wiping out the dinosaurs and other organisms in a hail of fire and catastrophic climate change. But new research shows that it also set the stage for life to rebound astonishingly quickly.

Global average temperature increases could pass the 1.5 degrees Celsius threshold outlined in the Paris Agreement by the end of the decade, according to the EU's Copernicus Climate Change Service, putting the world at greater risk of never-seen-before extreme weather events.