Henry David Thoreau once wrote that “it is better to have your head in the clouds, and know where you are… than to breathe the clearer atmosphere below them, and think that you are in paradise.” Climate scientists may well agree with this sentiment, as they endeavor to understand the complex role of clouds in our climate system.
Clouds continue to contribute the largest uncertainty to estimates and interpretations of the Earth’s changing energy budget, according the the 4th Assessment Report of the IPCC.
A new paper supported by NOAA’s Climate Variability and Predictability (CVP) program describes where we are in understanding whether subtropical clouds (and the atmosphere above and below them) will act as a positive or negative feedback to global warming.
In this Geophysical Research Letters article, Myers and Norris reduce this uncertainty using an observationally constrained formulation of the response of subtropical clouds to greenhouse forcing.” According to the paper’s abstract, “The observed interannual sensitivity of cloud solar reflection to varying meteorological conditions suggests that increasing sea-surface temperature and atmospheric stability in the future climate will have largely cancelling effects on subtropical cloudiness, overall leading to a weak positive shortwave cloud feedback.”
“The uncertainty of this observationally based approximation of the cloud feedback is narrower than the inter-model spread of the feedback produced by climate models,” the paper continued. “Subtropical cloud changes will therefore complement positive cloud feedbacks identified by previous work, suggesting that future global cloud changes will amplify global warming.”
To access a copy of this paper, visit: dx.doi.org/10.1002/2015GL067416