NOVA on PBS ~ Top Science Stories of 2021 ~ Climate & Weather

Extinction is real ... Recovery is problematic!

Scientific advancements helped humans push through both the pandemic and the atmosphere this year, and a long-awaited visit from some underground insects set the country abuzz.

Climate change and extreme whether

In August, the Intergovernmental Panel on Climate Change (IPCC) released its sixth climate assessment report, detailing the changes necessary to stop global temperatures from rising to levels that would cause undue environmental harm as well as potential steps to keep greenhouse gas emissions low enough to prevent widespread climate-related disasters.

There were temporary declines in carbon emissions in 2020 as a result of pandemic shutdowns, but the switch to remote work for many office-goers was not exactly friendlier for the environment. The IPCC’s conclusion? Yes—humans are warming the planet. It’s warmed to 1.09℃ since preindustrial times, and many of the changes as a result of this are irreversible.

If global warming stays below 1.5℃, particular damages, such as marine heatwaves and sea level rise, may reduce in frequency in the coming years. But if it exceeds 1.5℃ or even 2℃, the planet will see a significant and harmful shift in the frequency and progression of these and other climate damages.

Extreme weather has become more frequent and intense since 1950, the IPCC also reported, a shift perhaps exemplified this year by sandstorms, hurricanes, and typhoons.

On December 13, in a virtual press briefing at the annual meeting of the American Geophysical Union, researchers warned that Antarctica’s Thwaites glacier could collapse within three years. Nicknamed the “doomsday glacier,” Thwaites is the size of Florida and could cause sea levels to rise as much as two feet.

As of 2020, the gradual melting of Thwaites already accounts for 4% of global sea level rise on an ongoing basis. The amount of ice flowing from it and its glacial neighbors has almost doubled in the last 30 years. According to the latest reports, “Warming ocean water is not just melting Thwaites from below; it’s also loosening the glacier’s grip on the submerged seamount below, making it even more unstable,” Mindy Weisberger writes for Space.com.

Current mathematical models illustrate that if the Thwaites glacier were to collapse, much of western Antarctica’s remaining ice would become unstable.

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See also ~ NOVA | PBS — Rise of the Mammals ~ 53 minute video.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe. But we know little about how their successors, the mammals, recovered and took over the world. Now, hidden inside ordinary-looking rocks, an astonishing trove of fossils reveals a dramatic new picture of how rat-sized creatures ballooned in size and began to evolve into the vast array of species — from cheetahs to bats to whales to humans — that rule our planet today.