The reports came out at the same time an environmental think tank issued a report outlining climate changes that it attributes to greenhouse gas emissions. The reports also coincided with a report by congressional researchers advising members of the Senate Energy Committee about options for imposing a carbon dioxide cap-and-trade program.

The National Association of Manufacturers issued a white paper March 13 in which it cautioned the Senate Environment Committee against taking any steps toward capping carbon dioxide emissions, stating that such caps would "likely undermine the U.S. economy."

The manufacturing trade association argues that mandatory caps on carbon dioxide emissions would increase the prices of gasoline and diesel fuel by 8 percent to 9 percent by 2010.

"Mandatory caps would be detrimental to manufacturers by driving up the cost of doing business," said Keith McCoy, vice president for energy and resource policy for the manufacturers association.

The association is asking Congress to allow time for provisions in the Energy Policy Act of 2005 to encourage development of advanced energy technologies that would benefit energy conservation and carbon dioxide emissions.

"We should not even consider carbon mandates when the science is uncertain and recent policies addressing carbon intensity haven´t even been implemented yet," McCoy said.

One day later, the U.S. Chamber of Commerce released a statement calling on Congress to consider all alternative approaches before considering any legislative and regulatory action to reduce greenhouse gas emissions.

"We need common-sense solutions to this problem that won´t destroy our economy," said William Kovacs, Chamber vice president for environmental issues. "Any measures that fail to address long-term economic impact and the emergence of technological innovation will miss the mark and ultimately cause more harm than good."

Kovacs´ comments accompanied the release of a Chamber of Commerce report that raised concerns about a paper issued by the Congressional Budget Office on March 13. The Congressional Budget Office report outlined options the Senate would need to consider if it decides to implement a carbon dioxide cap-and-trade program. The report was prepared at the request of Sen. Jeff Bingaman, D-N.M., the ranking member of the Senate Energy and Natural Resources Committee.

The Congressional Budget Office paper raised questions about which parties would be regulated by a carbon dioxide cap-and-trade program and whether parties should be allowed to sell allowances or whether they should be given away.

Also on March 13, the World Resources Institute issued a report that concludes that human-induced climate change is already having quantifiable effects on the environment.

"The world may well have moved past a key physical tipping point," a WRI statement issued with the report states. "The science makes it clear that additional climate impacts will result even if emissions of greenhouse gases are halted immediately."

The WRI concludes that in addition to preventing additional climate change, there is an urgent need for efforts to adapt to the impacts already occurring.

All of the reports are available online. The Congressional Budget Office report is at www.cbo.gov/ftpdocs/70xx/doc7068/03-13-CommentsOnWhitePaper.pdf ; the WRI report is at http://climate.wri.org/climatescience-pub-4175.html ; the NAM report to the Energy Committee is at www.nam.org/s_nam/sec.asp?CID=43&DID=41 ; and the Chamber of Commerce report is at www.uschamber.com/issues/comments/060313climatechange.htm .