EPA: Green House Gas Emissions Fell in 2006
The EPA’s national greenhouse gas inventory has found that overall emissions decreased in 2006 by 1.1 percent from 2005. Those emissions include CO2, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride.
The biggest reduction was in CO2 emissions from fuel and electricity consumption, the EPA says. This was the result of several factors including: a warmer winter in 2006 that reduced heating needs, a decline in fuel consumption as fuel prices rose and more use of natural gas and renewable energy for electricity. Read the entire EPA inventory report here.
While this is good news, climate scientists like Richard Somerville, professor at University of California San Diego’s Scripps Institution of Oceanography, aren’t exactly jumping for joy. That’s because the 2006 U.S. reduction makes a tiny dent in world emissions. Somerville explained in an email why he focuses his attention on global atmospheric greenhouse gas concentrations:
[W]hat matters to climate is global atmospheric greenhouse gas amounts (concentrations), and these continue to increase, year after year. Also, global greenhouse gas emissions continue to increase year after year. Preventing climate damage requires stabilizing global greenhouse gas amounts, which in turn requires very large greenhouse gas emissions reductions globally.
Quantitatively, the position that I favor is expressed by the 2007 Bali climate declaration by scientists…which was signed by more than 200 expert climate scientists from more than 20 countries, each scientist signing simply as an individual, not on behalf of any organization.
Somerville pointed to the IPCC finding that global greenhouse gas concentrations need to ultimately get down to well below 450 parts per million. This is from the Bali declaration:
The 2007 IPCC report, compiled by several hundred climate scientists, has unequivocally concluded that our climate is warming rapidly, and that we are now at least 90% certain that this is mostly due to human activities. The amount of carbon dioxide in our atmosphere now far exceeds the natural range of the past 650,000 years, and it is rising very quickly due to human activity. If this trend is not halted soon, many millions of people will be at risk from extreme events such as heat waves, drought, floods and storms, our coasts and cities will be threatened by rising sea levels, and many ecosystems, plants and animal species will be in serious danger of extinction.
The next round of focused negotiations for a new global climate treaty (within the 1992 UNFCCC process) needs to begin in December 2007 and be completed by 2009. The prime goal of this new regime must be to limit global warming to no more than 2 ºC above the pre-industrial temperature, a limit that has already been formally adopted by the European Union and a number of other countries.
Based on current scientific understanding, this requires that global greenhouse gas emissions need to be reduced by at least 50% below their 1990 levels by the year 2050. In the long run, greenhouse gas concentrations need to be stabilised at a level well below 450 ppm (parts per million; measured in CO2-equivalent concentration). In order to stay below 2 ºC, global emissions must peak and decline in the next 10 to 15 years, so there is no time to lose.