People who support aggressive environmentalists usually deny that the philosophical underpinning of the movement has a goal of reducing economic activity and the standard of living of humans. The movement favors coercion to achieve its goals using central planning. Here is an article about the Bill Rees, guy who invented the "ecological footprint" (EF); someone who thinks we should all be living a 19th century lifestyle. It amazes me that the liberals who talk about being "progressive" actually want to go back to an earlier economy and lifestyle. (Occasionally one of them is honest enough to admit that the world has several times too many people for that economical model. Few address how the world should go about reducing population to the proper level.) At the end of this article, note the comments about CO2 absorption in North America. Liberals and environmentalists don't like to talk about that since it undermines their message. (For those that don't know, as air sweeps across North America from West to East, the CO2 concentration in the air actually falls, thus North America is a net CO2 sink rather than a source as the environmentalists like to
pretend.) Here is the article about Bill Rees and his EF concept:

http://www.thehumanspirit.net/New_Essays_8/ecological%20footprint%20and%20CO2%20sequestration.doc