U.S. Secretary of State Hillary Clinton today announced a new initiative to limit emissions of soot, methane, halocarbons and other short-lived global warming agents as a means to provide an immediate impact to slow the rate of human-caused climate change.
Decades of research by Veerabhadran Ramanathan, a distinguished climate and atmospheric scientist at Scripps Institution of Oceanography, UC San Diego, and colleagues have documented the effects of so-called "short-lived climate forcers" that influence atmospheric warming but only remain in the atmosphere for short periods of time. Work led by Ramanathan, dating back to his identification of chlorofluorobarbons (CFCs) as significant climate change agents in 1975, serves as the scientific underpinning of the initiative.
Five countries besides the United States - Canada, Mexico, Bangladesh, Sweden and Ghana - as well as the United Nations Environment Programme (UNEP) are members of the coalition advancing the intiative.
"This is a significant step towards fighting climate change that the world has been waiting for for such a long time," said Ramanathan, much of whose related research over the years has been funded by the National Science Foundation and NOAA. "It will also have a major impact in reducing air pollution and its negative impacts on health and the food security of developing nations."
In announcing the initiative, Clinton said coalition members will mobilize resources and develop action plans to encourage air pollution control measures in their countries. The United States will contribute $12 million toward a total $15 million investment to launch the effort, she said.
"The range of countries, organizations and industries gathered in this room today reflects the weight of scientific research showing that climate change is one of the most serious and complex problems facing our world," said Clinton at the announcement. "When we discover effective and affordable ways to reduce global warming, not by a little but by a lot, it is a call to action for all of us."
Recently Ramanathan and colleagues had issued a UNEP/World Meteorological Organization report and accompanying article in the journal Science highlighting 14 key air pollution control measures that if implemented could slow the pace of global warming, save millions of lives and boost agricultural production. They found that focusing on these measures could slow global mean warming 0.5 degrees C (0.9 degrees F) by 2050, prevent between 700,000 and 4.7 million premature deaths each year and increase global crop yields by up to 135 million tons per season. While all regions of the world would benefit, countries in Asia and the Middle East would see the biggest health and agricultural gains from emissions reductions.
Ramanathan noted that the immediacy of the benefit could also have the effect of making plain society's ability to manipulate climate in response to arguments that people are not capable of influencing such a large natural system. He and other contributors to the recent UNEP report emphasized that the concentration of resources toward mitigating climate change agents other than CO2 is not meant as a substitute for CO2 mitigation measures. The chief greenhouse gas caused by human activities, CO2 remains in the atmosphere for several centuries before completely breaking down. CO2 concentrations in the atmosphere have risen steadily for the past 100 years from a historical average rarely exceeding 300 parts per million to a level fast approaching 400 parts per million.
Previously scientists had identified a global average temperature increase of 2 degrees C (3.6 degrees F) as a threshold beyond which the world would almost certainly experience dangerous consequences from climate change. Ramanathan has calculated that reducing short-lived climate forcers by 30 to 50 percent could keep the warming below 2 degrees C until the end of the 21st century. He has further noted that technologies to achieve the goal - from establishing air pollution laws in the developing world to capturing methane emissions from landfills and pipelines - are already in existence.
"We've shown that while these emission controls cannot substitute for reductions in carbon dioxide emissions, they can provide societal benefits with economic valuations that usually exceed the cost of the emissions reductions, in many cases several times over," said Drew Shindell of NASA's Goddard Institute for Space Studies (GISS) in New York City, who led the UNEP report and the Science article. "We've provided a list of the most practical and beneficial actions that could be taken, and it's gratifying to see policy-makers respond so quickly to try and bring about these emission reductions."
Clinton added that the initiative complements other Obama Administration efforts to increase the energy efficiency of buildings, improve automotive fuel standards and increase the number of electric vehicles on American roads.
"We believe that today's announcement, if we do everything we want to do and intend to do, will be looked back on in coming years as a real turning point in the fight against the effects of climate change across our globe," she said.