Jackson has indicated the agency could implement new guidelines under the Clean Air Act, but the Obama administration would rather have Congress pass comprehensive energy and climate legislation, including a "cap-and-trade" program to reduce carbon emissions.
"The way to really tackle the problem is through legislation," Jackson said. "And we're hopeful that ... legislation will include 'cap-and-trade' and literally create, change the landscape of our energy economy."
The country may not yet see any direct action on environment laws, but today's EPA ruling gives President Obama the "climate stick" to use in an effort to get what he wants in an energy and climate bill from Congress.
"I think what he is saying to Congress is, 'Better for you to do it in a comprehensive way, but I've got the authority to move us down that path if you can't do it,'" said John Podesta, president and chief executive of the Center for American Progress. "I don't think it's a threat. I think it's a commitment to change the way the country produces and uses energy."
Some lawmakers have already expressed their support for the ruling. Rep. Henry Waxman, D-Calif., and Sen. Barbara Boxer, D-Calif., both issued statements commending the EPA's "endangerment findings." In concurrence with Obama, both Californians stressed that they favor using a more flexible legislative approach -- rather than EPA regulation -- to combat greenhouse gas emissions.
Obama repeatedly has stressed that his administration will focus on green jobs and creating a more comprehensive environmental policy.
President Obama affirmed his commitment in a speech in Mexico City, where the president met with President Calderon and other leaders to discuss trade and the economy.
"Together, we're establishing a new bilateral framework on clean energy and climate change that will focus on creating green jobs, promoting renewable energy, and enhancing energy efficiency," he said at a press conference on Thursday.
The framework will establish a mechanism for "political and technical cooperation and information exchange" to spur shared efforts between the two countries in developing clean energy economics.
The president echoed similar sentiment in February, when he visited Canada on his first international trip as commander-in-chief.
In March, the president said $59 billion in the Recovery Act and in tax incentives will go toward promoting clean energy. He announced $1.2 billion investment for research though the Department of Energy national labs.
"We know that enhancing America's competitiveness will require reducing our dependence on foreign oil and building a clean-energy economy," he said at a town hall meeting in California last month. "[The budget] makes clean energy the profitable kind of energy and invests in technologies like wind power and solar power, and fuel-efficient cars and trucks, and high-speed rail -- powered by batteries like the one I saw in Pomona earlier today -- all of which will help us combat climate change. That's got to be a priority."
Obama also can count on help from political allies in his environmental push. Former vice president Al Gore's group, the Alliance for Climate Protection, plans to launch a national campaign to get a climate change bill passed this year. The high-profile and well-funded campaign is expected to grab the attention of lawmakers, but question remains on what the administration's next steps will be.
For the time being, environmental activists are popping open champagne bottles and rejoicing in their victory, which they say comes after eight years of stagnation.
"For the last several years, we've been on the sidelines not playing," Mendelson said. "It's sort of a proud moment -- almost a being-a-papa moment."