Once in a while I see some talk about how increasing carbon dioxide levels in the atmosphere cannot be causing any global warming, because carbon dioxide only absorbs infrared radiation in certain narrow bands, and all the radiation in those bands is already captured by the current level of carbon dioxide. Sounds like good news! But I've always seen this argument buried among numerous other good news arguments, and somehow as I checked out each one and wound up disappointed, I never quite made it down the list to check out the saturation argument.
Until now. Here's a fine summary, and a fine example of the work of Spencer Weart. He is the author of The Discovery of Global Warming: A hypertext history of how scientists came to (partly) understand what people are doing to cause climate change. If you haven't dipped into that website yet, well, I wish you would.
2 weeks ago