The former vice president, now known internationally as a climate-change guru, told the Senate Foreign Relations Committee that the United States must participate in the United Nations climate talks in Copenhagen later this year with a cap-and-trade system already in place, putting the country in the driver’s seat to negotiate the successor to the Kyoto Treaty.

“If Congress acts right away to pass President Obama’s recovery package and then takes decisive action this year to institute a cap-and-trade system for CO2 emissions…the United States will regain its credibility and enter the Copenhagen treaty talks with a renewed authority to lead the world in shaping a fair and effective treaty,” Gore said.

“And this treaty must be negotiated this year,” he declared. “Not next year – this year.”

The committee chairman, Sen. John Kerry (D-Mass.), warned lawmakers that increasing global warming emissions – which grew four times faster during the Bush administration than in the 1990s – will present a national security catastrophe, complete with more natural disasters and human displacement if an emissions cap is not enacted quickly.

“Frankly, the science is screaming at us,” Kerry said. “Some may argue that we cannot afford to address this issue in the midst of an economic crisis. They have it fundamentally wrong. This is a moment of enormous opportunity.”

Kerry is a member of a climate-change working group that also includes Sens. Joseph I. Lieberman (I-Conn.) and Barbara Boxer, chairwoman of the Senate Environment and Public Works Committee. And both Kerry and Gore are expected to play an integral role in negotiating international consensus on how to tackle the planet’s rising temperatures.

The two men teamed up in 1988 for the Senate’s first-ever climate change hearing and attended United Nations climate talks in Poland last December.

The Senate hearing room filled with murmurs as Gore presented a slide show depicting dramatic increases in melting polar ice caps, eroding shorelines and forecasts that millions of people would be displaced by climate change worldwide in the coming years.

Calling Gore’s testimony “dramatic and remarkable,” Kerry ordered a copy of it distributed to every member of the Senate.

While Obama has committed to an aggressive 80 percent reduction in 1990 level emissions by 2050, he has not clearly stated whether he would attempt to pass legislation this year, even with the increased Democratic majorities in the House and Senate.

Coal state Democrats have voiced concerns about the toll an emissions cap would have on the coal industry in their states – potentially resulting in more job losses in an already tattered economy. So, Sen. John D. Rockefeller IV (D-W.Va.), among others, is pushing a stimulus provision for clean coal research as an environmentally friendly alternative.

But Gore said that technology would be extremely expensive and won’t be available for years, urging that coal industry jobs to be transferred to new job markets.

“The research is one thing, but we must avoid becoming vulnerable to the illusion this technology is near at hand. It is not,” Gore said.

Still, Sen. Bob Corker (R-Tenn.) and other coal state lawmakers may help turn the tide.

“I agree with you that carbon capture and sequestration is a long way off,” Corker said. “My mind has a hard time…understanding how it will be done.”

In order to emerge from Copenhagen with a successful climate-change agreement, Gore said world leaders must agree on strong targets and timetables from industrialized nations, while allowing China, India and other developing nations less stringent standards.

China and India were not included in the original Kyoto policy, but many leaders, including former President George W. Bush argued they should be.

Gore appeared at a warm-up session for treaty talks in Poland in December – a meeting designed to build momentum for this year’s formal negotiations.

But the talks there did little to create a blueprint for Copenhagen, and environmentalists still doubt whether leaders will emerge from this year’s meeting with a deal.

With the chances of passing climate legislation appearing bleak, some environmentalists are urging the new Obama administration to use the Clean Air Act to regulate power plant emissions, which wouldn’t require legislation. And Obama announced earlier this week that he would ask the Environmental Protection Agency to reconsider the applications of 14 states looking to set more aggressive greenhouse gas standards.