Methane, black carbon, tropospheric ozone growing climate change threats; Clean Air Task Force advocates for SLCF mitigation strategies to complement CO2 reductions

On Tuesday, June 14 the United Nations Environment Program (UNEP) released the full text of its long-awaited report: “The Integrated Assessment of Black Carbon and Tropospheric Ozone,” following the distribution in February of the report’s Summary for Decision Makers.

Key findings of the report include:

  • The global climate is changing now, warming most rapidly in polar and high-altitude regions, where black carbon’s role in darkening of snow and ice exacerbates already dangerous climate trends.
  • Black carbon (BC) can disturb tropical rainfall and regional circulation patterns such as the Asian monsoon, affecting millions of people on the subcontinent. Ozone can also reduce crop yields, and together these pollutants lead to many premature deaths worldwide.
  • In the U.S. and Europe, older diesel engines are responsible for about 60% of black carbon emissions, and are the fastest-growing source of black carbon emissions in developing countries.
  • Implementing aggressive emission reductions of black carbon, and contributors to tropospheric ozone, including methane, could cut projected climate warming by as much as 0.5 degrees Celsius, or about 0.9 degrees Fahrenheit, by 2070. Such cuts could be made with existing technology and through current political structures, and would have immediate and multiple benefits for human health and that of the planet.

Mitigation strategies for reducing SLCFs can be implemented quickly, and positive results can be expected over a shorter time frame, according to Clean Air Task Force climate scientist Ellen Baum.

For instance, in the U.S., local, state and federal efforts are underway to reduce the black carbon component of diesel pollution, said Brooke Suter, National Diesel Clean-up Campaign Director, and the Clean Construction Act of 2011 was introduced federally in May 2011 to incorporate clean construction principles in the federal Transportation Reauthorization bill due out this month.

Watch the UNEP website for supporting materials.