Scratch the surface, however, and it becomes apparent that the problem is not just the number of people but their consumption. And we Americans are the worst.
Nobody consumes as much, per capita.
For more on the population question, see Negative Population Growth . At this site they track environmental groups for their position on population growth and immigration. Immigration is a politically difficult idea- although it seems elitist to deny immigration, many immigrants maintain the high fertility rates of their homeland after arriving in the US, meaning their descendants are both numerous and superconsumers. This site also has links to other organizations that promote political activities that will reduce population worldwide, such as empowering women, encouraging family planning, and reducing tax and other incentives to large families. The US census site has US and world population statistics and projections, such as below.