On Thursday, two senators introduced a bipartisan proposal to address climate change. Sens. Chris Murphy (D-CT) and Susan Collins’ (R-ME) Super Pollutants Act of 2014 will reduce short-lived climate pollutants. These pollutants are responsible for around 40 percent of global warming, making them the second-largest contributor after carbon dioxide, which is accounts for about 55 percent of the global “greenhouse effect.”
Known as “super pollutants,” because they are much more potent than carbon dioxide, short-lived climate pollutants (SLCPs) stay in the atmosphere for much less time. Experts say reducing super pollutants now will reduce temperatures and air pollution in the near term, and protect public health and strengthen food security.
“Short-lived climate pollutants are the problem too few people are talking about, but are doing some of the worst damage to the atmosphere,” Murphy said in a statement. “As we work to combat threats to our climate, we can’t leave short-lived pollutants out of the equation.”
The act targets three specific super pollutants: hydrofluorocarbons (HFCs), black carbon, and methane.
HFCs, used in air conditioning and refrigeration, are hundreds to tens of thousands of times more potent than CO2 but only stay in the atmosphere for about 15 years. Black carbon — a major element of soot from wildfires, cook stoves, and natural-gas-fueled power generators — is the largest contributor to global warming after carbon dioxide. It is far more potent than carbon dioxide, but has an atmospheric lifespan of only days or weeks.
And finally, methane, emitted in large quantities by the natural gas, petroleum, and agriculture industries, is 20 times as potent as CO2 and has an atmospheric lifespan of about 12 years.
The Super Pollutants Act of 2014 builds on a similar act introduced by Rep. Scott Peters (CA-52) in the House last year. The Senate act, like the House act, calls for the establishment of a task force to produce best policy practices for reducing U.S. and international consumption of super pollutants and provide recommendations to Congress for plans to lower emissions and utilize clean alternatives.
The Senate bill also introduces additional actions, including initiatives to reduce black carbon through the International Maritime Organization, the Arctic Council, the Climate and Clean Air Coalition, U.S. Agency for International Development, and the Department of State — in part building off of U.S. efforts to limit emissions from diesel.
It also extends the Clean Air Act’s regulations on servicing and disposal of equipment using ozone-depleting substances to HFCs; developing energy efficient and cleaner alternatives; and supporting a joint US-Canada-Mexico proposal for a global phasedown of HFCs.
The bill calls for studying ways to reduce the venting and leakage of methane emissions from venting and flaring, gas drilling, landfills, coal mining, and agriculture, both in the U.S. and internationally. As natural gas production booms domestically, methane leakage from those operations is becoming a serious concern.
In addition to temperature decrease, actions to limit super pollutants yield significant health and agricultural benefits. Action on super pollutants could reduce warming by half a degree Celsius, prevent 0.7 million to 4.7 million annual deaths, and increase annual crop yields 35 million to 130 million metric tons due to ozone reductions in 2030 and beyond.
International leaders and scientists have long maintained that in order to avoid the worst impacts of climate change, global warming must be held to a 2° Celsius temperature increase. Currently, the world is on track for at least a 4° Celsius (7.2° Farenheit) rise in temperature by the end of the century.
Any plan to slow the rate of climate change and stay below the 2° C limit must include reductions in carbon emissions, but even if the U.S. makes drastic cuts in CO2 production today, the benefits will not be evident for decades, making action on super pollutants critical for mitigating the effects of climate change in the short term.
Eliza Dach is an intern with the Center for American Progress studying at Yale University. Rebecca Lefton is a Senior Policy Analyst specializing in International Sustainable Development at the Center for American Progress.