Elevated atmospheric CO2 and deserts: Will increasing CO2 alter deserts and the desertification process?

The human species has had a tremendous impact on the earth\u27s environment. One of the most significant effects of anthropogenic activities is that on the composition of the earth\u27s atmosphere through increases in atmospheric content of carbon dioxide (CO2) and other trace gases (Vitousek et al. 1997). Except for human land use, no type of global change has been documented to be more substantial and rapid than the increase in atmospheric CO2 content. From the beginning of the industrial age (ca. 1850) until today, atmospheric CO2 concentration has risen from approximately 280 to 360 ppm (Keeling and Whorf 1990), a 30% rise in just the last 140 years. This rise is continuing, with a doubling of current-day CO2 concentration projected to occur by the middle of this century. Increased CO2 represents the most important human enhancement to the greenhouse effect. The consensus of the climate research community is that it has already had a detectable influence on the earth\u27s climate (Stott et al. 2000; Levitus et al. 2001), and will further drive substantial climate change during the 21st century (Schneider 1992)