Global Climate Change Greenhouse Gases

Mankind s impact on the global climate and whether pollution from modern energy use is indeed warming the Earth have become important issues for national and international policy makers. Political pressure and public sentiment are based on complex data sets that, alone, cannot tell the whole story. The ultimate question is whether our climate is becoming warmer because of the slow build-up in atmospheric greenhouse gas concentrations (1). The answer is not clear, because much of what we know about global climate change is inferred from historical evidence of uncertain quality. 

In Eq. (LL), A// is the heat of vaporization of water and R is the gas constant. Thus the vapor pressure of water has an exponential dependence on temperature. This suggests that there may be a water vapor feedback associated with global climate change. If the atmosphere warms, for example due to increased greenhouse gases such as C02, increased concentrations of gaseous water are expected in accordance with Eq. (LL). The increased water vapor traps more thermal infrared radiation, warming the atmosphere further (e.g., Raval and Ramanathan, 1989 Stenchikov and Robock, 1995). 

Greene, D.L. Schafer, A. Reducing Greenhouse Gas Emissions from US. Transportation, Pew Center on Global Climate Change Arlington, VA, 2003 1-80. 

In his cover letter to President Clinton, John Gibbons, director of the White House Office of Science and Technology and PCAST s co-chairman, said the country needed to improve its R D effort, especially in relation to the challenge of responding responsibly and cost-effectively to the risk of global climate change from society s greenhouse gas emissions, in particular, carbon dioxide from combustion of fossil fuels. ... 

Because huge quantities of methane are buried in the seafloor, mainly as gas hydrates, there are concerns about potential climate effects, especially because methane has a greater greenhouse effect than C02. The concentration of atmospheric methane is also presently increasing at a more rapid rate than that of C02 (IPCC, 2001). Therefore, the abundance, distribution (in space and time) and the stability of methane hydrates have important implications for future and past global climate changes. 

Margolick, M. and Russell, D. (2001). Corporate Greenhouse Gas Reduction Targets, Pew Center on Global Climate Change Washington, DC. 

---