We really don't know clouds

Via Making Light, this Discover blog post tells us about NASA's climate-change website, which is pretty damn good -- I wish there were something equally concise and well-organized for natural selection.

The part that made me think of Joni Mitchell was from the "Uncertainties" section:

Clouds have an enormous impact on Earth's climate, reflecting back into space about one third of the total amount of sunlight that hits the Earth's atmosphere. As the atmosphere warms, cloud patterns may change, altering the amount of sunlight absorbed by the Earth. Because clouds are such powerful climate actors, even small changes in average cloud amounts, locations, and type could speed warming, slow it, or even reverse it. Current climate models do not represent cloud physics well, so the Intergovernmental Panel on Climate Change has consistently rated clouds among its highest research priorities. NASA and its research partners in industry, academia, and other nations have a small flotilla of spacecraft and aircraft studying clouds and the closely related phenomenon of aerosols.

Young scientists would be well advised, then, to have their heads in the clouds.