WASHINGTON -- Sen. Barbara Boxer left little doubt that she was having a particularly good time on Wednesday.
Wearing sunglasses, California's junior Democratic senator made her way to a stage on the east lawn of the Capitol, then stood in front of a huge U.S. flag and waved to a throng of supporters as U2's "It's a Beautiful Day" roared through the loudspeakers.
"What a great day!" enthused the senator. "This is like giving birth again!"
Boxer celebrated one of the biggest days of her 17-year Senate career as she teamed up with Massachusetts Democratic Sen. John Kerry to introduce a long-awaited bill that, if approved, could land her in the history books.
The landmark legislation -- called the Clean Energy Jobs and American Power Act -- would force the U.S. to cut greenhouse gas emissions by 20 percent by 2020, setting more ambitious targets than a bill that passed the House this summer. By 2050, greenhouse gas emissions would be reduced by 80 percent from 2005 levels.
Sponsoring a bill, of course, is the easy part. The hard part will come next, as Boxer tries to fend off many Republicans and some Democrats who want to derail the legislation by suggesting it would be far too costly, particularly during tough economic times.
Opponents are ready for battle, saying Boxer and Kerry are out to impose a new national tax on energy.
"The national energy tax was a terrible idea when it passed the House, and it is an even worse idea now," said House Minority Leader John Boehner of Ohio. "Middle-class families and small businesses struggling to make ends meet shouldn't be punished with costly legislation that will increase electricity bills, raise gasoline prices and ship more American jobs overseas."
Environmentalists counter that it's time to hold polluters responsible and to invest in clean-energy projects in the United States.
"For years, we've relinquished control of our energy sector to other countries and to big corporate interests," said Earthjustice president Trip Van Noppen.
While some critics said the bill doesn't go far enough, Kerry said it initially would affect 7,500 facilities that account for nearly 75 percent of U.S. carbon pollution.
"These are big polluters," he said, adding that more than 98 percent of American businesses and all farmers will be exempt.
After laboring over global warming and environmental issues for years, Boxer is better positioned this year to leave her mark on a climate-change bill. She has headed the Senate's environmental committee since 2007, but this year marks the first that she has a Democratic ally in the White House.
The bill would create a system that would create financial incentives for companies to clean up their pollution as soon as possible. Essentially, companies requiring more time to reduce their carbon pollution could pay for the right to keep polluting, while businesses that met their goals quickly would be rewarded.
"No one knows what challenges will face them in their time," Boxer said. "No one chooses their time. But you know what? This is our time. Global warming is our challenge."
President Barack Obama and Republican Gov. Arnold Schwarzenegger were both quick to salute Boxer and Kerry for their leadership.
"With the draft legislation they are announcing today, we are one step closer to putting America in control of our energy future and making America more energy independent," Obama said.
Schwarzenegger said climate change "is real and threatens the health, safety and economic stability of our world."
"I applaud Senators Boxer and Kerry for introducing climate change legislation that builds on many of California's first-in-the-nation policies, including our aggressive cap on global warming pollution, complementary emissions standards, and our innovative plan to reduce emissions by curbing sprawl," he said. "I will work to ensure that the bill preserves our ability to fight global warming pollution and grow clean energy jobs right here in California."
While the White House and Senate leaders insist a global warming bill is firmly on track, its introduction was delayed because of Congress' ongoing battle over revamping the nation's health care system.
Boxer said the climate bill "addresses major challenges of our generation" by seeking to protect children and the Earth from pollution, putting the U.S. back in control of its energy future, creating policies that will lead to up to 1.9 million new jobs and inspiring similar actions from other counties.
And she said it would do much to help the California economy. She cited a report by Pew Charitable Trusts that said 10,000 new clean energy businesses were launched in California from 1998 to 2007. During that period, clean energy investments created more than 125,000 jobs and generated jobs 15 percent faster than the California economy as a whole, Boxer said.
"My state of California is going through hard times right now and it weighs on me every day," she said. "But there is one bright spot. And that is clean energy jobs and businesses."