Contraception is the cheapest solution to global warming...

...so says a report commissioned by the Optimum Population Trust, carried out by the London School of Economics. Link to the news release here:

http://www.optimumpopulation.org/releases/opt.release09Sep09.htm

Here's a link to another article mentioned on the OPT site about carbon legacy of individuals:

http://blog.oregonlive.com/environment_impact/2009/07/carbon%20legacy.pdf