Computer models used to predict climate change could have a major flaw in how they determine the ability of clouds to cool the planet, a new paper published in Science suggests — and, if true, the new research means that making progress against rising temperatures is going to be even more difficult than was long expected.
The new paper looked at "mixed-phase" clouds, which are made up of both cooled water and ice crystals, The New York Times reports. Using data from a satellite monitoring the particles in the atmosphere, mixed-phase clouds appear to scientists to have more water and less ice than was first expected. Because water reflects solar radiation back into the sky, watery clouds help slow warming. But with less ice to begin with, there is naturally less of an ability for water to replace the ice, according to the scientists behind the new research. As a result, more warming occurs than was at first predicted.
If the data proves to be true, it could mean there will be an additional 1.3 degrees Celsius of warming than was modeled previously. Last year's climate talks in Paris had scientists agreeing to keep temperatures from rising more than 1.5 degrees over the Earth's temperature during the preindustrial era. That would have required keeping global temperatures from rising more than 2 degrees Celsius — so if the research on clouds proves to be correct, the range remaining for the Paris goal has shrunk to just 0.2 degree Celsius from 0.7 degrees.
"Every model will react differently: It could be higher, it could be lower [than 1.3 degrees]," the paper's author, Ivy Tan, said. "The point is, it's going to result in a significant amount of warming."