This is getting ridiculous. It looks like "global warming" is joining President Bush as the root cause of everything.

http://www.foxnews.com/story/0,2933,236120,00.html

It is not clear to me how a very small increase in the amount of carbon dioxide in the atmosphere would cause a reduction in air density 400 miles up. I think carbon dioxide is heavier than oxygen and nitrogen. How would more of it reduce density in space?