A coalition of 38 nations and several international groups have launched the Global Methane Initiative , accelerating shared efforts to cut pollution of a gas that accounts for about one-fifth of the warming potential of all greenhouse gases. And the climate benefits of cutting emissions of methane are more immediate: It persists in the atmosphere for a decade or so, while CO2 lasts for hundreds of years. Methane is also a more potent warmer.
Scientists and advocates mostly lamented the failure in Copenhagen to create a global, comprehensive, and mandatory deal on greenhouse emissions. But there's growing recognition that agreements like the methane initiative can chip away at the problem without requiring arduous political steps. "Countries can work together to reduce greenhouse gas emissions today. This shows you can make progress while you work on the most difficult issues," Environmental Protection Agency official Dina Kruger told ScienceInsider.
"It's a good step forward, showing how the technology can work in the real world," says climate scientist Drew Shindell of NASA in New York City. Last year Shindell showed that complex atmospheric chemistry  allows methane to indirectly expand the warming capacity of stratospheric water vapor, aerosols, nitrates and sulfates. "Methane has been undervalued."
This pact expands and renames the global Methane to Markets Partnership, created in 2004.
The U.S. led efforts to create the Partnership, which runs cooperative projects, emphasizes work that does not require new inventions to reduce pollution from the gas. From that organization's 2009 status report:
For many of the major emission sources, significant reductions are possible using currently available, cost-effective technologies. Many of the available reduction options involve the recovery and use of methane as a fuel for electricity generation, on-site uses, or off -site gas sales. These actions represent key opportunities for reducing emissions from animal waste management, coal mines, landfills, and natural gas and oil systems.
The new initiative expands the partnership by adding waste water, a sector thought to be responsible for 9% of anthropogenic methane emissions. It also will move the focus of nations from simply collecting methane that is emitted to preventing it from being created. That could be done, said Kruger, for example by reducing the amount of yard waste put in landfills, where it is broken down in a way that creates methane.
The effort, begun with 14 nations, has funded roughly 300 projects that have led to the removal of the equivalent, in warming terms, of 40 million tons of CO2.
In many cases methane collection projects can eventually pay for themselves, since the gas can be removed from landfills, agricultural waste containers, or fossil fuel facilities and sold as natural gas. (When methane is burned it creates the less potent greenhouse gas CO2.) Shindell says it's useful for U.S. facilities, like wastewater treatment plants, to share their technological know-how on collecting and selling the gas or burning it for cheap power. (That's how methane projects can make cleaner water "more affordable," says Kruger. Shindell says, however, that "substantial" economic or other barriers in the developing world require "things like financing or additional incentives"—not part of the new initiative.
Advocates hope that work to reduce emissions of potent, short-lived pollutants including methane, black carbon, and some refrigerants could reduce warming on the short term. That, in turn, could protect the Arctic  as its temperature rises dramatically. Towards that end the eight nations that make up the Arctic Council agreed  last year to accelerate research and deployment of various programs to cut methane pollution.
But Shindell warns that cutting non-CO2 gasses is not a way to "buy time" if CO2 emissions continue unabated. "This is no substitute to dealing with CO2 if we want to avert serious warming on the long run," he says.