No good news here: Key IPCC findings on climate change
— Read on phys.org/news/2021-08-good-news-key-ipcc-climate.html

The UN Intergovernmental Panel on Climate Change’s first major scientific assessment since 2014, released Monday, shows unequivocally that global warming is unfolding more quickly than feared and that humanity is almost entirely to blame.

Here is a rundown of some of its key findings from the IPCC Working Group 1 report on physical science:

Goodbye 1.5C, hello overshoot

Earth’s average surface temperature is projected to hit 1.5 or 1.6 degrees Celsius above preindustrial levels around 2030 in all five of the greenhouse gas emissions scenarios —ranging from highly optimistic to reckless—considered by the report. That’s a full decade earlier than the IPCC predicted just three years ago.

By mid-century, the 1.5C threshold will have been breached across the board, by a tenth of a degree along the most ambitious pathway, and by nearly a full degree at the opposite extreme.

There is a silver lining: in the most ambitious if-we-do-everything-right scenario, global temperatures—after “overshooting” the 1.5C target—fall back to 1.4C by 2100.