It's getting hot in here: Climate change demands action

Greenhouse gases trap solar energy that is reflected by the atmosphere and the earth's surface in the form of heat; major greenhouse gases include carbon dioxide, methane, and nitrous oxide.

The United Nations' Intergovernmental Panel on Climate Change (IPCC), including over 2,000 of the world's climate scientists, says that established emission reduction targets for greenhouse gases are inadequate, and far more radical solutions must be found. IPCC scientists estimate that unless levels in the air are stabilized by mid-century, Earth's average temperature could rise 5.8 degrees by 2100, producing devastating effects, possibly including the stopping of the Gulf Stream, which will freeze the northeast U.S. and western Europe.

The rate of CO2 accumulation is accelerating. Average CO2 levels increased by 2.08 parts per million (ppm) in 2002 and 2.5 ppm in 2003, to an average of 375.6 ppm worldwide-the first recorded example of the average CO2 level jumping more than 2 ppm in two consecutive years. The average increase for the prior 20 years was 1.5 ppm. The current level of CO2 is the highest in at least 420,000 years.

If this rate of increase is maintained all our global warming predictions to the end of this century will have to be recalculated. Just as there is no safe cigarette, there is no safe level of CO2 atmospheric increase.

Where does it all come from? Well, about 200 fossil-fuel power plants operated by five U.S. energy producers emit 646 million tons of CO2 each year. The Sierra Club compiled results of 27 health studies done both in the U.S. and abroad showing strong links between traffic-related air pollution and asthma, cancer, premature and low birth weight babies, heart attacks and generally higher risk of death.

And we are not just choking ourselves. Many other species are also at risk from bad air. A study published in Nature in January 2004 found that over 1 million species, or 24 percent of all species, would eventually become extinct due to climate change projected to occur by 2050. This risk could be significantly reduced by acting soon to reduce emissions of CO2 and other heat-trapping gases.

The articles in this issue explore ways that each of us can make concrete contributions, today and in the near future, to reducing the threat of global warming.

Jan Kidwell is chair of the Chapter's Air Quality, Global Warming and Energy Committee.