In another decisive shift from the Bush administration's environmental policies, the government took a new stance on greenhouse gases that is expected to radically change the landscape of U.S. environmental policy.
The Environmental Protection Agency (EPA) determined that carbon dioxide, and five other greenhouse gases spewing out of tailpipes, "endanger public health and welfare" of the American people. These gases, they said, contribute to climate change, which is causing more heat waves, droughts and flooding, and is threatening food and water supplies.
The EPA's mandate is a critical step toward amending climate change regulations. It gives President Obama the ammunition, under the 40-year-old Clean Air Act, to order emissions reductions and tighten regulations. That could include measures such as requiring more fuel-efficiency in cars and less carbon dioxide emission at plants and industries.
"It's a serious problem for us and for the world," EPA Administrator Lisa Jackson recently told ABC News. "And the impacts of climate change are not just life and death, but they are economic costs that are hard to extrapolate into the future."
Industry insiders say the EPA's decision also is important because it sends a signal to the world that the United States is going to be a partner in solving the problem.
"The EPA's action is the first major step that our government has taken towards regulating global pollution," said Joe Mendelson, director for global warming policy at the National Wildlife Federation. "It is a game changer ... the most significant step that our government has ever taken to deal with the climate change crisis."
Proponents of stricter standards hailed the EPA's decision.
"This is a momentous day, a great moment," said David Doniger, climate policy director for the Natural Resources Defense Council. "We've been trying for more than 10 years to get the government to make the simple statement that this global warming pollution is dangerous. And for the last eight years, it was too hard for the last administration to utter those words.
"Less than 90 days into the new administration, President Obama and his team are moving in global warming in a real way," Doninger added.
But it is also already causing an uproar in the business community. Critics say the administration's actions could cost jobs -- as many as two million -- and drive up energy prices. There also is concern that it will lead to government regulation of office buildings, planes, ships, farms, even cows, which are big methane gas producers.
"If they decide to ... regulate under the Clean Air Act, that literally puts EPA in charge of entire economy," said Bill Kovacs, vice president for the Environment, Technology and Regulatory Affairs Division at the U.S. Chamber of Commerce.
"It would be a disaster," he added. "They're trying to pressure Congress and the business community to do something that they would really rather not do, because they also know that there is a risk that this regulatory cascade will actually go into effect."
Kovacs said any change in clean air laws will first and foremost hurt programs being funded by President Obama's stimulus money. While the projects may have been cleared for pollutants, they have not been cleared for carbon dioxide, Kovacs added.
Despite the landmark decision, it remains unclear how the EPA will use its authority to regulate greenhouse gas emissions.