SOURCE: AP
DATE: January 4, 2020
SNIP: The amount of baked-in global warming, from carbon pollution already in the air, is enough to blow past international agreed upon goals to limit climate change, a new study finds.
For decades, scientists have talked about so-called “committed warming” or the increase in future temperature based on past carbon dioxide emissions that stay in the atmosphere for well over a century. It’s like the distance a speeding car travels after the brakes are applied.
But Monday’s study in the journal Nature Climate Change calculates that a bit differently and now figures the carbon pollution already put in the air will push 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 a degree Celsius (1.8 degrees Fahrenheit) less than that amount of committed warming.
International climate agreements set goals of limiting 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 warmed about 1.1 degrees Celsius (2 degrees Fahrenheit).
“You’ve got some … global warming inertia that’s going to cause the climate system to keep warming, and that’s essentially what we’re calculating,” said study co-author Andrew Dessler, a climate scientist at Texas A&M University. “Think about the climate system like the Titanic. It’s hard to turn the ship when you see the icebergs.”
Dessler and colleagues at the Lawrence Livermore National Lab and Nanjing University in China calculated committed warming to take into account that the world has warmed at different rates in different places and that places that haven’t warmed as fast are destined to catch up.