Climate-driven weather extremes will worsen without deep emissions cuts: UN

Human-caused global warming from the emission of fossil fuels is already affecting extreme weather in every region across the world, which will become more frequent and intense with every additional increment of warming, the United Nations said in a new report Monday.

Many changes due to past and future greenhouse gas emissions are irreversible for centuries, especially deep ocean warming, ice sheet melt, and sea-level rise.

But the world is inching closer to reaching a temperature threshold that would lead to even worse consequences unless governments take action in the coming decades to cut emissions deeply.

Since the last report in 2013 by the U.N. Intergovernmental Panel on Climate Change, compiled by the world's leading climate scientists, both greenhouse gas emissions and the average global temperature have continued to climb.

The Earth has already warmed 1.2 degrees Celsius since the Industrial Revolution. Each of the last four decades has been successively warmer.

The latest U.N. report says the world will hit 1.5 degrees of warming in about 12 years if emissions don’t fall. If that happens, it would represent a failure of the Paris Climate Agreement, under which countries pledged to hold total global warming to “well below” 2 degrees and agreed to “pursue efforts” to limit warming to 1.5 degrees.

In 2019, the concentration of carbon in the atmosphere was higher than at any time in at least 2 million years, the report said.

“The ship has kind of sailed on 1.5 degrees,” Zeke Hausfather, a climate scientist at the Breakthrough Institute who contributed to the report, told the Washington Examiner.