Here, I added the link to this new article in SCIENCE without the corresponding article in NATURE GEOSCIENCE. It is included in this article itself.
That NATURE GEOSCIENCE article makes a prediction of a second, far more extensive Climate Crisis in the next Century, based on Climate Models where cloud cover is poorly understood, and long past the time that Humanity will have either: (1) dealt with the present Climate Crisis, (2) adapted to it, or (3) become extinct.
Thus, it is of little current in the present debate on how Humanity should stop emissions, and resolve the present Climate Crisis. In other word, one crisis at a time.
“Could the sheets of gray clouds that hang low over the ocean disappear suddenly in a warming world? Yes, if you believe a study published yesterday in Nature Geoscience—and the amplifying media coverage of it. If atmospheric carbon dioxide (CO2) levels triple—an unlikely, but not implausible scenario given past rates of human emissions—these stratocumulus clouds could vanish in a frightening feedback loop. Fewer of the cooling clouds would mean a warmer Earth, which in turn would mean fewer clouds, leading to an 8°C jump in warming—a staggering, world-altering change.
“But many climate scientists who research clouds are pushing back against the study, arguing that its analysis of one small patch of atmosphere does not apply to the entire globe. It’s a “simple model [that] essentially has a knob with two settings,” says Joel Norris, a cloud scientist at the Scripps Institution of Oceanography in San Diego, California. “But it is very likely that the Earth has more knobs than that.”
“As sophisticated as they are, climate models have a hard time dealing with clouds. Condensing moisture and turbulent air form clouds at scales smaller than models can directly simulate, so instead they use approximations for this behavior. To understand clouds better, scientists have instead developed high-resolution eddy simulations, which re-create the life of small parcels of the atmosphere, including key physics of cloud formation that climate models can’t handle directly.
“Several years ago, a project comparing six leading eddy simulations looked at how just a 2°C temperature rise influenced low ocean clouds. Two dynamics emerged that caused the clouds to thin, exacerbating warming. First, higher temperatures allowed more dry air to penetrate thin clouds from above, preventing them from thickening and reflecting more of the sun’s energy. Second, increased CO2 levels trapped heat near the cloud tops, preventing their cooling. Because such cooling drives the turbulence that forms clouds, the effect could impede cloud formation, fueling further warming. If emissions continued, it seemed plausible that these low clouds would melt away.
“The frustration with how poorly global models handle clouds was a primary reason that Tapio Schneider, a climate dynamicist at the California Institute of Technology (Caltech) in Pasadena and the new study’s lead author, began construction of a new climate model last year. Dubbed the Climate Machine, it would use artificial intelligence to learn from eddy simulations and satellite observations to improve its rendering of clouds. Doing so first meant building, with his team, their own eddy simulation, one that could dynamically interact, or couple, with the ocean, allowing the simulated clouds to spur warming and vice versa.
“The new study, which uses this eddy simulation, shows the same feedbacks that others had previously identified. But Schneider ran it for much higher CO2 concentrations than most had done. As levels reached 1200 parts per million—three times what they are today, and a number that could be reached next century if no effort is made to stop climate change—the low cloud decks rapidly withered away…”