The US Environmental Protection Agency (EPA) shifted course Friday by deeming carbon dioxide and other greenhouse gases a health risk, in a landmark turnaround that could impact climate change regulation.
"After a thorough scientific review ordered in 2007 by the US Supreme Court, the Environmental Protection Agency issued a proposed finding ... that greenhouse gases contribute to air pollution that may endanger public health or welfare," said an EPA statement posted on the agency website.
The move, which could open the door to stronger regulation on greenhouse gas emissions, marks a significant shift on climate change from the previous presidency of George W. Bush, which failed to heed EPA warnings on the possibly devastating consequences of inaction.
"This finding confirms that greenhouse gas pollution is a serious problem now and for future generations. Fortunately, it follows President (Barack) Obama's call for a low carbon economy and strong leadership in Congress on clean energy and climate legislation," said EPA Administrator Lisa Jackson.
"This pollution problem has a solution -- one that will create millions of green jobs and end our country's dependence on foreign oil.
"As the proposed endangerment finding states, 'In both magnitude and probability, climate change is an enormous problem. The greenhouse gases that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act,'" she added.
Five out of the nine Supreme Court justices ruled in April 2007 that carbon dioxide was a pollutant under the Clean Air Act, in place since 1970.
They ordered the EPA to decide if the greenhouse gas endangered public health and welfare and said that if a so-called endangerment finding was made, the agency must draft rules to reduce vehicle emissions of carbon dioxide.
In December 2007, the EPA sent a draft finding to the Bush White House, presenting evidence that CO2 did endanger public welfare.
But the Bush administration failed to acknowledge the report and spent the remainder of its tenure resisting the Supreme Court decision.
Many environmental groups have criticized Bush's refusal for eight years to take action over the crisis and have accused his administration of manipulating or ignoring science to pursue inaction at any cost.
The EPA's action "is a wake-up call for national policy solutions that secure our economic and environmental future," said Vickie Patton, deputy general counsel at the Environmental Defense Fund, which called the agency's move an "historic step."
The Union of Concerned Scientists, a leading non-profit group on climate issues, said the EPA has acknowledged the "massive body of scientific research that shows that climate change is harming our health and environment."
Heat waves, the spread of tropical diseases and worsening air quality are all threats the EPA can help address, said the organization.
Opposing the EPA's endangerment findings, however, the fossil fuel-reliant industry representative Electric Reliability Coordinating Council (ERCC) said the development could have considerable, negative impacts on traditional industries throughout the United States.
"If reliance upon coal-fired generation were to diminish by a third as a result of EPA regulatory programs, GDP would be reduced by about 166 billion dollars, household incomes by 64 billion dollars, and employment by 1.2 million jobs," said ERCC director Scott Segal.
"To the extent green jobs are created, they would come only after severe trauma to the economy and would likely be lower-paying than the manufacturing jobs they displace."
Earlier this month in Prague, Obama vowed that the United States was "now ready to lead" on climate change.
The US Congress is examining a draft bill for clean energy development that aims to cut carbon emissions by 20 percent from their 2005 levels by 2020 and boost reliance on renewable sources of energy.
But although the US targets were unheard of before Obama took over from Bush, they were given an extremely cautious welcome in Europe because the base year for comparisons is 15 years after that of the EU.
The new US goals, though welcome, represent just a five to six percent reduction using the EU's baseline of 1990, EU Environment Commissioner Stavros Dimas said earlier this month. German Environment Minister Sigmar Gabriel described them as "not enough."