A full 75% of the loss of global forests occurred in the 20th century and there are signs that this rapid deforestation is continuing. Not only has the rising population created a greater total demand for forest products but the per capita global use of paper and paperboard has nearly tripled since 1961. The loss of forest areas reduces habitat for wildlife and carbon storage which is key to regulating climate. Moreover, the loss of forest areas compromises erosion control, the provision of water across rainy and dry seasons and the regulation of rainfall.
Climate change is much on the minds of many scientists. Over the last half century, carbon emissions from fossil-fuel burning expanded at nearly twice the rate of population growth, boosting atmospheric concentrations of carbon dioxide, the principal greenhouse gas, by 30% over pre-industrial periods. Emissions from developing countries will nearly quadruple over the next half century, while those from industrial nations will increase by 30%. Former Senator and Democrat Presidential candidate Al Gore’s excellent fact-filled presentation on the subject of global warming runs entirely counter to any idea that population is not a problem. The UN estimates conservatively that America produces 20 metric tons of pollutants per capita annually. If America's population increases by 300 million by the end of this century, an additional six billion tons of pollutants will be produced per year at the present rate. Even if by some technological miracle we were to be able to cut our per capita output in half to that of Mexico, we would have made no progress on reducing the present unacceptable total output.