FILE – The January 10, 2009 file photo shows a flock of geese flying past a chimney at the Jeffery Energy Center coal-fired power plant near Emmitt, Kan. A new study says the amount of global warming already baked into the air due to past carbon pollution is enough to exceed internationally agreed climate limits. A study on Monday, January 4, 2021, gives a different view of what is called committed warming, which comes from heat-trapping gases that remain in the atmosphere for more than a century. (AP Photo / Charlie Riedel, File)
FILE – The January 10, 2009 file photo shows a flock of geese flying past a chimney at the Jeffery Energy Center coal-fired power plant near Emmitt, Kan. A new study says the amount of global warming already baked into the air due to past carbon pollution is enough to exceed internationally agreed climate limits. A study on Monday, January 4, 2021, gives a different view of what is called committed warming, which comes from heat-trapping gases that remain in the atmosphere for more than a century. (AP Photo / Charlie Riedel, File)
The amount of ingrained global warming, from carbon pollution already in the air, is enough to blow past internationally agreed targets to mitigate climate change, a new study finds.
But it’s not a game over, because while that amount of warming may be inevitable, it could be delayed for centuries if the world quickly stops emitting additional greenhouse gases from the combustion of coal, oil and natural gas, the study authors say.
Scientists have been talking for decades about so-called “committed warming” or the rise in future temperature based on past carbon dioxide emissions that remain in the atmosphere for more than a century. It is like the distance a speeding car travels after the brakes have been applied.
But Monday’s study in the journal Nature Climate Change calculates that a little differently and now calculates that the carbon pollution that has already stopped in the air will drive global temperatures to about 2.3 degrees Celsius (4.1 degrees Fahrenheit) of warming since pre-industrial times.
Previous estimates, including those accepted by international science panels, were about one degree Celsius (1.8 degrees Fahrenheit) less than that amount of dedicated warming.
International climate agreements set targets to limit warming to 2 degrees Celsius (3.6 degrees Fahrenheit) since pre-industrial times, with the more ambitious goal of limiting it to 1.5 degrees Celsius (2.7 degrees Fahrenheit) added in Paris in 2015. The world has already done this. warmed up about 1.1 degrees Celsius (2 degrees Fahrenheit).
“You have a … sluggishness of global warming that’s going to keep the climate system warming up, and that’s essentially what we’re calculating,” said study co-author Andrew Dessler, a climate scientist at Texas A&M University. ‘Think of the climate system such as the Titanic. It is difficult to turn the ship when you see the icebergs. “
Dessler and his colleagues from the Lawrence Livermore National Lab and Nanjing University in China calculated that global warming has been committed to take into account that the world has warmed at different rates in different places and that places that are not so fast. are warmed up, destined to catch up.
Places like the Southern Ocean around Antarctica are a bit cooler, and that difference creates low-lying clouds that reflect more of the sun away from Earth, keeping these places cooler. But this situation cannot go on indefinitely, because physics dictates that cooler locations will heat up more and when they do, the clouds will decrease and more heating will occur, Dessler said.
Previous studies were based on the cooler spots staying that way, but Dessler and colleagues say that’s not likely.
External experts said the work is based on compelling reasoning, but want more research to show it to be true. Zeke Hausfather, climate scientist at the Breakthrough Institute, said the new work fits climate models better than observational data.
Just because the world will undoubtedly warm more than international targets doesn’t mean all will be lost in the fight against global warming, Dessler said., who warned against what he called “climate doomers.”
If the world hits zero carbon emissions soon, 2 degrees of global warming could be delayed enough that it won’t happen for centuries, giving society time to adapt or even come up with technological solutions, he said.
“If we don’t, we’ll break through (climate goals) in a few decades,” Dessler said. “It is really global warming that makes climate change so terrible. If we were to hit a few degrees in 100,000 years, that wouldn’t be such a big problem. We can deal with that. But a few degrees over 100 is really bad. “
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