Browner said the administration would like to have comprehensive legislation in hand before a planned U.N. climate conference in Copenhagen in December.
"It is the strong preference of the administration that we secure legislation," Browner said. "Copenhagen and the position we can take will be driven by what we are prepared to do domestically."
Browner made her comments at a forum at the Massachusetts Institute of Technology hosted by Democratic Rep. Edward Markey, chairman of the Select Committee on Energy Independence and Global Warming.
A bill co-authored by Markey is set to come up for a hearing in Congress. The bill would require 25 percent of the nation's electricity come from renewable sources by 2025. It also would create a cap on global warming pollution, push the production of electric cars and require improvements to the nation's electric grid.
Markey said if Congress fails to act, the Environmental Protection Agency may have to set new regulations on greenhouse emissions — a process that he warned would carry "less flexibility" than congressional action.
"Industries across the country will have to gauge how lucky they feel," he said.
Markey also said that during an initial transition period some emission credits would have to be given away to protect energy-intensive industries — in part to prevent sudden spikes in prices — but that in the long run the goal is to auction off all the credits to generate revenue.
Obama has championed a "100 percent auction" of emission credits. He has said the money raised from the auctions could go toward a range of programs, including clean energy projects and helping people cope with higher energy costs.
Browner said renewable energy is not just good for the planet, but could help reinvigorate the nation's economy as it emerges from the current fiscal turmoil. She said the solar and wind energy industry could create 2 million jobs over the next decade.
She said the $65 billion in loan guarantees and other financial incentives for the renewable energy sector included in the federal stimulus package is designed to keep as many of those jobs as possible in the U.S.
John Holdren, director of the White House Office of Science and Technology Policy, said the country needs to have a sense of urgency in the fight against global warming, which could alter the environment, sparking droughts, floods, wildfires and explosions of pests. While there's no way to completely stop climate change, he said, steps can be taken to prevent it from worsening.
Options include constructing millions of wind turbines and hundreds of nuclear power plants, doubling the fuel efficiency of cars to an average 60 miles per gallon, and developing solar panels for homes that "are as cheap as paint."
"It will take more than an Apollo program, more than a Manhattan project," he said.