Two small island nations, worried by rising sea levels, proposed drastic global cuts Thursday in the use of hydrofluorocarbons, a class of powerful greenhouse gases commonly used as coolants in refrigerators and air conditioners.
Micronesia and Mauritius urged 195 nations that signed on to the U.N. ozone treaty to reduce consumption of HFCs by 90 percent by 2030.
"Continuing to emit these super greenhouse gases is irresponsible when we have climate and ozone-friendly alternatives available," said Masao Nakayama, Micronesia's ambassador to the U.N.
The two nations said "near-term abrupt climate change threatens our way of life and, in some cases, our very existence."
The treaty encourages using HFCs to replace ozone-depleting chlorofluorocarbons, or CFCs, which have now been virtually eliminated.
A global fund affiliated with the ozone treaty has invested billions in creating new markets for HFCs and other chemicals that do not harm the protective ozone layer above the earth. But HFCs, like CFCs, are powerful climate-warming chemicals – up to 10,000 times more so than carbon dioxide.
HFCs account for only about 2 percent of the globe's climate-warming gases, but scientists say eliminating their use would spare the world an amount of greenhouse gases up to about a third of all CO2 emissions about two to four decades from now.
Two leading U.S. senators wrote President Barack Obama on Thursday to express "strong support" for U.S. backing to use the 21-year-old ozone treaty to phase down HFCs by 85 percent by 2030.
"By phasing down these gases, the global community will be able to achieve significant near-term climate change benefits," wrote Sens. Barbara Boxer of California, who heads the Environment and Public Works Committee, and John Kerry of Massachusetts, head of the Foreign Relations Committee.
The ozone treaty, they said, is "well-equipped to prevent HFC emissions" by regulating their production and consumption and promoting alternatives.
The deadline for proposing an amendment to the ozone treaty is Monday, six months ahead of a scheduled treaty meeting.
The U.S. has been weighing such a proposal.
Officials at the Environmental Protection Agency have called it a preferred option, and the Defense Department already has prepared for phasing down HFCs.
The State Department, too, drew overwhelming support for such a plan from participants at two meetings this year, recalled one participant, Mack McFarland, global environmental manager for Delaware-based DuPont Fluorochemicals.
White House spokesman Benjamin LaBolt said Thursday, however, that "the administration has not developed a position on this."
Manufacturers already have begun to replace HFCs with so-called natural refrigerants such as hydrocarbons, ammonia or carbon dioxide.
McFarland said his company, one of only five in the U.S. that make HFCs, supports a "phase-down" of HFCs to about one-fifth of their current use. He estimated the U.S. market for HFCs is $1 billion, about a third to one-half what it is globally.