GREENHOUSE GAS EMISSIONS

Estimates of future emissions and removals depend in part on assumptions about changes in underlying human activities. For example, the demand for fossil fuels such as gasoline and coal is expected to increase greatly with the predicted growth of the U.S. and global economies.

The Fifth U.S. Climate Action Report concluded, in assessing current trends, that greenhouse gas emissions increased by 17 percent from 1990-2007. Over that same time period, the U.S. GDP increased by 65 percent and population increased by 21 percent. This is a very interesting fact, but also The dominant factor affecting U.S. emissions trends is CO2 emissions from fossil fuel combustion, which increased by 21.8 percent over the 17-year period. The declines in methane emissions are mostly due to increased collection and combustion of landfill gas, as well as improvements in technology and management practices at natural gas plants. The decline in nitrous oxide emissions is largely due to the installation of newer N2O control technologies in motor vehicles throughout the past decade. Fluorinated substances (HFCs, PFCs, and SF6) accounted for 2 percent of total U.S. GHG emissions in 2007. The increasing use of these compounds since 1995 as substitutes for ozone depleting substances has been largely responsible for their upward emissions trends. (Fifth U.S.Climate Action Report, 2010)

Many, but not all, human sources of greenhouse gas emissions are expected to rise in the future. This growth may be reduced by ongoing efforts to increase the use of newer, cleaner technologies and other measures. Additionally, our everyday choices about such things as commuting, housing, electricity use and recycling can influence the amount of greenhouse gases being emitted. If green house gases keep progressively getting worse, then what does this mean for a future on this earth? The place you call home? Only time can tell.