It's the catch-22 of sustainable trade-offs: The chemicals used to replace ozone-destroying chlorofluorocarbons (CFCs) contribute to global warming. But hydrofluorocarbons (HFCs), which replaced CFCs in air-conditioning units and refrigerators, do not trap heat on the same scale as common greenhouse gases, like methane and carbon dioxide. No, HFCs can trap 4,470 times as much heat as carbon dioxide.
It all goes back to the 1970s, when scientists realized that CFCs, also used in foam insulation, were eroding the layer of ozone that protects the earth. HFCs, considered a safe replacement, were phased in during the 1980s and 1990s, and 96% of all ozone-depleting chemicals were replaced, according to the United Nations. The hole in the ozone began to shrink.
While the original compounds, CFCs, had the destructive ability to break up ozone molecules, the replacement, HFCs, have much stronger bonds. Much stronger bonds mean a much greater ability to absorb and retain heat. It's a problem that has only recently been addressed, as last month a group of scientists published a study that suggested emissions of these "super" greenhouse gases could have serious repercussions.
David Fahey, with the National Oceanic and Atmospheric Administration, is concerned that the release of HFCs flies under the radar when people look at greenhouse gases. "Whatever targets you thought you were going to make, it will be undermined by the fact that you have
additional emissions that you hadn't planned on," he said.
Scientists worry that HFCs, which only account for about 2% of the U.S.'s climate-warming power, are strong enough to erase any efforts made at reducing greenhouse gases.
"You have this moment when you could nip this problem in the bud and avoid this very large growth of a dangerous chemical," David Doniger, policy director at the Natural Resources Defense Council's climate center, said. "Now, in the next couple of years, is when you have to do this."
SOURCE: Washington Post