It's been two years since the U.N. Intergovernmental Panel on Climate Change laid out the definitive case that human beings were causing global warming, and two decades since NASA scientist James Hansen first told Congress of the threat of rising CO2 emissions. So, why has it taken this long for the Environmental Protection Agency (EPA) to announce that greenhouse gases endanger human health? Change can be slow in Washington.
On March 20 the EPA sent what is called an "endangerment finding" to the White House, a proposal that means the agency found that there is a scientific case that man-made global warming poses a threat to human welfare. (Reporters found out about the EPA decision the following Monday, after it was posted on a government website.) The finding is a response to an April 2007 Supreme Court decision ordering the EPA to figure out how CO2 from cars should be regulated under the Clean Air Act.
Scientific staff in the George W. Bushera EPA found that CO2 is a pollutant, but then administrator Stephen Johnson rejected the recommendation and delayed the process of regulating it, part of the Bush Administration's general obstructionism on climate change. When Lisa Jackson took over the EPA under the new President, however, she told Congress that one of her first acts would be to reevaluate her predecessor's decision, and she didn't drag her feet. "It's an exercise in leadership that takes the first step in regulating CO2 emissions from automobiles," says John Walke, the clean air director for the Natural Resources Defense Council.
By concluding that greenhouse gases pose a threat to human welfare, the EPA's finding could lay the groundwork for nationwide regulation of CO2 emissions just as the EPA is require to regulate pollutants like smog-causing sulfur dioxide. But regulating CO2 will be immensely more complicated the U.S. emitted over 6 billion metric tons of CO2 in 2007 from countless sources and business groups have raised the specter of a meddlesome EPA using greenhouse gases as an excuse to regulate projects large and small.
While the EPA has so far been silent about how it might actually regulate CO2 and the endangerment finding is only an early step in a process that could take a year or longer environmentalists say it's difficult to imagine that the agency would attempt to control every possible source of greenhouse gas emissions. "People running the EPA have common sense," says Frank O'Donnell, head of the environmental group Clean Air Watch. "They're going to focus the efforts on the biggest sources" like the auto industry and the utility sector.
Of course, if the Obama Administration achieves its stated goal of passing carbon cap and trade legislation, EPA regulations might be superseded and even deep greens generally prefer Congressional action to federal fiat. But with cap and trade looking like it may become a victim of the White House's need to prioritize amidst a sea of crises, the EPA's actions could provide a much-needed nudge to Congress. "This is a strong message," says O'Donnell. "Congress either has to face the reality that something has to be done, or the Obama Administration will just do it itself." What's one more item on the world's longest Presidential to-do list?