WASHINGTON - Three top U.S. climate scientists stressed on a telephone press conference today the United States must rapidly reduce its global warming emissions to avoid the worst consequences of climate change. The scientists, all of whom have been involved in U.N. Intergovernmental Panel on Climate Change (IPCC) reports, were speaking during a telephone press briefing organized by the Union of Concerned Scientists (UCS).

An environmental activist walks next to a snowman as part of a climate change awareness action in Berlin January 22, 2010. (REUTERS/Fabrizio Bensch) The prospects for federal action on climate are uncertain. Some senators have suggested the Senate may not consider a climate bill this year. Meanwhile Sen. Lisa Murkowski (R-Alaska) has introduced a resolution that would undermine the Environmental Protection Agency's (EPA) authority to regulate heat-trapping emissions under the Clean Air Act.

"Policymakers must understand that unlike a steel tariff, action on climate change is not something that can be postponed a year," said Richard Somerville, a research professor at Scripps Institution of Oceanography and co-author of the Copenhagen Diagnosis, a synthesis of the most policy-relevant climate science since the 2007 IPCC report. "The longer we delay in reducing our emissions, the higher the global temperature increase we lock in."

Reporters on the call asked the scientists for their perspective on the controversy surrounding stolen emails from the University of East Anglia's Climate Research Unit and an error about Himalayan glaciers in an IPCC report.

"It's time for policymakers to pay attention to the atmosphere and not the blogosphere," said Peter Frumhoff, UCS's director of science and policy. "While climate naysayers spout all sorts of excuses for not taking action, heat-trapping emissions continue to accumulate in the atmosphere, making the problem worse."

Robert Corell, a scientist with the Arctic Governance Project and the Global Environment and Technology Foundation, reminded reporters that the science is solid. "The vast body of peer-reviewed literature speaks for itself," Corell said. "Claims that say otherwise are completely unjustified."

Some climate legislation opponents now are calling for a stand-alone energy bill that includes renewable energy and energy efficiency standards without a cap on carbon emissions. This approach would fail to deliver the necessary emissions reductions, said Frumhoff. Scientists have indicated that cuts of at least 80 percent below 2005 levels by 2050 are required. To reach that goal, the government must ensure reductions of at least 20 percent below 2005 levels by 2020.

The energy bill passed by the Senate Energy Committee in July, which could go to the Senate floor, would not reduce emissions enough and therefore should not be seen as a substitute for a comprehensive climate bill, according to UCS. Because of its various loopholes and exemptions, the bill would do less to promote renewable energy sources than state policies already in place.

Conversely, a cap like the one in the House's "American Clean Energy and Security Act," which it passed last June, would put a price on carbon emissions, providing a market incentive for polluters to reduce their emissions and rewarding clean technology innovations.

"Economists agree that a carbon price is a critical, cost-effective way for the United States to reduce its emissions and transition to a clean energy economy," said Rachel Cleetus, an economist at UCS. "A strong cap would encourage investments in clean energy sources and energy efficiency and help ensure that U.S. companies capture a share of the growing global market in clean technologies. Green is the new red, white and blue."

The clean tech industry is the growth industry of the future, she said. The United States must act quickly to secure a leadership role in this industry, rather than ceding it to China and other nations that are rapidly expanding their renewable energy industries.

A cap would not interfere with economic growth, Cleetus added. According to the EPA, Energy Information Administration and Congressional Budget Office, the U.S. economy would continue to grow robustly under the cap in the House "American Clean Energy and Security Act." Costs to households, meanwhile, would be marginal. By contrast, the costs of inaction could be immense, according to a report UCS issued last year. Unchecked climate change will likely impose massive social, environmental and economic losses from rising sea levels, intense coastal storms, erratic weather patterns, drought and flooding, crippled infrastructure, and collapsed ecosystems.

"A bill that creates a cap would generate significant revenues to help in the transition to a clean energy economy," said Cleetus. "Revenues could be used to subsidize weatherization and other improvements in energy efficiency that would save money for low- and middle-income households, as well as to train workers for new clean energy jobs."

Finally, if Congress does not enact an emissions reductions plan sometime in the next few months, it will lower worldwide confidence in the United States' ability to live up to its pledge, to reduce emissions "in the range" of 17 percent below 2005 levels by 2020, in the Copenhagen Accord, said UCS Director of Policy and Strategy Alden Meyer, who has been involved in international climate negotiations for 20 years. "Much would depend on President Obama's ability to lay out a clear path forward for the United States to meet its commitment in the absence of Senate action."