How can atmospheric CO2 be stabilized?
Global atmospheric concentrations of carbon dioxide (CO2) have increased significantly since the dawn of the Industrial Age around 1750, when the world’s atmospheric concentration of CO2 stood at about 280 parts per million (ppm). Writing in the August 13, 2004, issue of Science magazine, Princeton University professors S. Pacala and R. Socolow noted that proposals to limit atmospheric CO2 levels to a concentration that would prevent the most severe levels of climate change have focused on a goal of 500 ±50 ppm. As of July 2007, the global CO2 concentration was about 383 ppm. If we take no action to curb CO2 emissions, energy demand growth and other factors are likely to cause CO2 atmospheric concentrations to more than double in the next 50 years — the so-called “business-as-usual” scenario that some believe will usher in catastrophic climate change. According to Pacala and Socolow, stabilization of CO2 levels at 500 ppm requires that emissions be held near the current level of 7 bill
