Although most of the focus in Copenhagen is on reducing emissions of carbon dioxide, negotiators are also looking at other greenhouse gases, reports Jim Tankersley in the Los Angeles Times. Methane, which is produced by livestock and landfills, has 23 times the global warming potential of CO2. Hydrofluorocarbons are used in refrigeration and cooling, and came into wide use after the Montreal Protocol slashed the use of CFCs because they damage the ozone layer; that agreement’s structure could now help speed the phase-out of HFCs.
While not actually a gas, black carbon is also a major contributor to climate change – by one estimate, it’s responsible for 18% of the world’s warming. These particles of soot come from biomass-burning cookstoves and some ships, and retain the sun’s heat rather than allowing it to be reflected back up into the atmosphere. Black carbon deposited on snow and ice can speed melting, which contributes to sea level rise and water-supply problems.
Tankersley notes that addressing these less-high-profile contributors is potentially easier than tackling CO2 emission:
Many scientists and environmentalists say reducing the “forgotten 50%” of pollutants will be faster, easier and substantially cheaper than cutting carbon dioxide, and could buy the world time in its climate clock race.
“We can eliminate — not just cut — one of the six greenhouse gases this week,” said Durwood Zaelke, a longtime environmental lawyer who is president of the Institute for Governance and Sustainable Development. “This can buy us more than a decade of delay” against the worst effects of climate change, he said.
Action on black carbon and hydrofluorocarbons is a particularly appealing goal for island nations concerned that the world may be nearing “tipping points” of global warming, in which increased greenhouse gas concentrations in the atmosphere start a chain reaction of temperature rise that would lead to their nations being swallowed by rising seawater.
The island nations are desperate for measures that will reduce warming in the short term. Black carbon is an ideal target because it stays in the atmosphere for only a few weeks, compared with 100 years for carbon dioxide, meaning that if black carbon emissions were eliminated, atmospheric heat-trapping would drop quickly.
This doesn’t let us off the hook when it comes to cutting CO2 emissions, and shouldn’t distract from that important task, either. The ability to pursue multiple solutions simultaneously is essential for saving the planet.