Today United Intergovernmental Council of Nations on Climate Change published an alarming new report on the state of the climate: 14,000 scientific literature synthesized by hundreds of experts. It’s a full statement of what scientists know about how humanity set the planet on fire: how hot it is and how hot it will become, how much the polar ice is melting, how droughts and storms are getting worse, how scary the road ahead is – unless we take drastic action and immediate steps to stop the carbon load on the atmosphere.
“We’ve known the world is warming for decades, but this report tells us that recent climate change is widespread, rapid, and intensifying – unprecedented in thousands of years,” said Ko Barrett, IPCC vice president and senior climate adviser at the National oceans and atmosphere, at a news conference Sunday where the report was released. “The conclusion is that unless there is an immediate, rapid and comprehensive reduction in greenhouse gas emissions, a heating limit of 1.5 degrees C or 2.7 degrees Celsius will be unattainable.”
That limit is an optimistic goal Paris Climate Agreement: maintain global average temperatures at 1.5 degrees Celsius above pre-industrial levels and avoid warming of 2 degrees. The new report notes that the temperature has already risen by 1.1 degrees, and is on track to reach 1.5 sometime in the early to mid-2030s if things don’t change.
This is a significant update by a previous IPCC report which predicted the planet would reach 1.5 milestones around 2040, says Zeke Hausfather, a climatologist and director of climate and energy at the Breakthrough Institute, who was not included in the report. “Similarly, we pass 2 degrees somewhere between the early 2040s and early 2050s as the most likely estimate in higher-emission scenarios,” he says, referring to one of the five outcomes modeled in the new report.
Why is half a degree so important? “There is a big difference between 1.5 and 2,” in terms of deterioration drought,, heat waves,, storms,, floods,, melting ice, i rising sea levels, says Janos Pasztor, executive director of the Carnegie Climate Governance Initiative and former UN Assistant Secretary-General for Climate Change, who was not included in the report. “Two are getting much worse. And that above 2 got a a lot a lot worse. And there are chances, of course, that we will go in that direction. ”
The report makes projections of what would happen in five different greenhouse gas emission scenarios: They envision a future in which humanity produces different levels of carbon, from very low to very high. (In the lowest scenario, emissions fall to zero around 2050 and continue to fall. In the highest, they double by that year.) In other words, the climate is predicted to look dependent on the rate at which our civilization decarbonizes.
The accompanying color-coded graph in the report also shows what would happen to global temperatures and rainfall depending on how much the climate warms, and states how many regions of the world have experienced an increase in extreme heat, rainfall and drought. (Tip: That’s almost all of them.)