(AP) -- The Obama administration called hydrofluorocarbons widely used in refrigerators and air conditioners "a very significant" threat to climate change Monday, and expressed a preference for drastically reducing HFCs that are promoted under the U.N.'s ozone treaty rather than phasing them out entirely.
But a senior State Department official stopped short of endorsing a formal proposal last week by the two small island nations of Micronesia and Mauritius to alter the ozone treaty known as the Montreal Protocol by cutting HFCs by 90 percent by 2030.
The treaty promotes the use of HFCs, a class of powerful greenhouse gases, to replace ozone-depleting chlorofluorocarbons, or CFCs, that have now been virtually eliminated. But while HFCs do not harm the ozone layer, they are especially potent greenhouse gases - up to 10,000 times more so than carbon dioxide.
Micronesia and Mauritius wanted to include an HFCs phase-out in the ozone treaty discussions planned for November, calling it a dire matter of survival for their island inhabitants as sea levels rise.
The deadline for making such a proposal was this week.
0fficials at the State Department, the Environmental Protection Agency and the Defense Department had all backed a reduction of HFCs, but the idea ran into some resistance in the White House during a year when the administration is considering all its negotiating chips for the successor to the Kyoto climate treaty that expires in 2012.
The United States ran out of time "to complete the analysis needed to understand the potential impacts of such an approach or to consider how amending the Montreal Protocol to address HFCs would affect negotiations ... with respect to the post-2012 period," Daniel Reifsnyder, a deputy assistant secretary for environment and sustainable development, wrote in a letter to U.N. Ozone Secretariat Marco Gonzalez.
"We plan to continue actively studying and analyzing this issue," he wrote.
Proponents of the idea were disappointed.
"We cannot hesitate as a third of our future global warming emissions hang in the balance. We need action - and U.S. leadership - this year," said Alexander von Bismarck, executive director of the Environmental Investigation Agency, a nonprofit watchdog group in Washington that first pitched the idea two years ago.
Only about 2 percent of the globe's climate-warming gases are currently HFCs, but those are expected to grow to up to about a third of all greenhouse gases about two to four decades from now because of their promotion for a host of household goods that once used CFCs.
Some manufacturers, however, have already begun to replace HFCs with so-called natural refrigerants such as hydrocarbons, ammonia or carbon dioxide. Companies like Delaware-based DuPont Fluorochemicals, one of only five U.S. manufacturers of HFCs, say they support a global "phase-down" of HFCs to about one-fifth of their current use.
The U.S. market for HFCs is estimated at $1 billion, about a third to one-half what it is globally.
Senate Foreign Relations Chairman John Kerry said Monday that "HFCs are significantly more powerful greenhouse gases than carbon dioxide, and the damage is only going to grow if we don't act in the short term."
He said in reaction to the administration's letter that President Barack Obama now "clearly recognizes the impact of HFCs, and I'm confident he'll work with Congress to find a way to address this growing challenge in the best and quickest way possible."
Last week, Kerry had joined with another leading Democrat, Senate Environment Chairwoman Barbara Boxer, in urging Obama to express strong support for using the ozone treaty to phase down HFCs by 85 percent by 2030.
In contrast to the proposed phase-down, Reifsnyder noted that a preliminary EPA analysis is based on "stepwise reductions" which would reduce HFCs by 85 by 2039. Legislation before the House already calls for U.S. reductions in HFCs.
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