Figures on population growth are no doubt daunting. Consider:
Between 1850 and 1970, the world's population tripled, while energy consumption increased 12-fold.
By 2002, the number of people grew by 68 percent and fossil fuel consumption grew by another 73 percent.
Population will increase by another 41 percent by 2050, to 8.9 billion people, according to the United Nation's population division. Ninety-nine percent of that growth will occur in developing countries.
However, growing numbers of people cannot be considered without also thinking about the consumption habits of those people, according to experts at the Worldwatch Institute. For example, there are about 3 million additional Americans each year and about 16 million additional Indians. The 3 million Americans, however, will add 15.7 million tons of carbon pollution to the world. All 16 million additional Indians, though, will add 4.9 million tons of carbon pollution.
Distribution of population is another important factor. In the United States, 53 percent of the population lives on just 17 percent of the land -- concentrated in coastal areas. For the overburdened coastal areas, that translates into more waste, higher water and energy demands, and the loss of wetland habitats for wildlife.