Short-lived Air Pollutants and Climate Change
IIASA’s GAINS model is effectively reframing the international climate debate, demonstrating that air pollution is no longer just an ancillary benefit of reducing greenhouse gas (GHG) emissions, but a key means of reducing GHGs in the shorter term.
In 2011 research conducted by IIASA’s Mitigation of Air Pollution and Greenhouse Gases Program (MAG) using GAINS demonstrated a compelling way of promoting climate change mitigation in the shorter term through reduction of short-lived air pollutants.
In some countries, climate change mitigation ranks low on the policy agenda. Thus, implementing long-term measures against carbon dioxide and other GHGs that remain in the atmosphere for decades can seem irrelevant, despite the powerful arguments in favor of “intergenerational” responsibility.
In common with GHGs, most air pollutants act as climate forcers, although on a
shorter time scale (carbon dioxide, c. 100 years; methane, 12 years; soot, a few weeks). Mitigating air pollution thus not only reduces temperature increase in the near term but also has short-term tangible benefits that are highly relevant for local policy agendas: better human health and well-being, improved local environment, better food and energy security, and lower water demand.
Of the 2,000 options available in GAINS for improving air quality, MAG researchers
identified 16 that, together, could reduce the global warming potential of short-lived
air pollutants by up to 60%. These range from extended recovery of coal mine gas to
mandatory installation of particle filters on diesel engines. The IIASA findings were the
focus of a joint United Nations Environment Program–World Meteorological Organization
research project “Integrated Assessment of Black Carbon and Tropospheric Ozone,”
published in February 2011.
NASA’s Goddard Institute for Space Studies then modeled the 16 GAINS measures
to identify those with the greatest climate benefits—14 in total. The results were
widely reported, including in the 13 January 2012 edition of Science. Moreover,
a new global climate initiative based on the 14 GAINS measures has just been
announced by U.S. Secretary of State, Hillary Rodham Clinton.
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