Tuesday, April 03, 2012

EPA Releases Final Report To Congress On Black Carbon

Apr 2: U.S. EPA released its final Report to Congress on Black Carbon which has been in the making for several years. The October 2009 Interior Appropriations bill (P.L. 111-88) required EPA, in consultation with other Federal agencies, to prepare a comprehensive report to Congress on the climate effects of black carbon. Black carbon, or soot, results from incomplete combustion of organic matter such as fossil fuels and biomass. The report to Congress evaluates and synthesizes available information on sources of black carbon, impacts of black carbon on global and regional climate, and the potential utility and cost-effectiveness of mitigation options for reducing climate and public health impacts of black carbon.

    EPA's Office of Air Quality Planning and Standards (OAQPS) submitted a draft report to its Science Advisory Board Advisory, Council on Clean Air Compliance Analysis in March of 2011. EPA
requested that the Council review the draft report to evaluate the report's scientific rigor and technical accuracy. The SAB completed its review in August 2011 [See WIMS 8/15/11].
    The final report indicates that black carbon (BC) emissions have important impacts on public health, the environment, and the Earth's climate. BC is a significant component of particle pollution, which has been linked to adverse health and environmental impacts through decades of scientific research. Recent work indicates that BC also plays an important role in climate change, although there is more uncertainty about its effects on climate than for greenhouse gases (GHG), such as carbon dioxide and methane. BC has been linked to a range of climate impacts, including increased temperatures, accelerated ice and snow melt, and disruptions to precipitation patterns. Importantly, reducing current emissions of BC may help slow the near-term rate of climate change, particularly in sensitive regions such as the Arctic. However, BC reductions cannot substitute for reductions in long-lived GHGs, which are necessary for mitigating climate change in the long run.

    Despite the rapidly expanding body of scientific literature on BC, there is a need for a more comprehensive evaluation of both the magnitude of particular global and regional climate effects due to BC and the impact of emissions mixtures from different source categories. To advance efforts to understand the role of BC in climate change, on October 29, 2009, Congress requested EPA to conduct a BC study as part of H.R. 2996: Department of the Interior, Environment, and Related Agencies Appropriations Act, 2010 (i.e. P.L. 111-88). Specifically, the legislation stated that: "Not later than 18 months after the date of enactment of this Act, the Administrator, in consultation with other Federal agencies, shall carry out and submit to Congress the results of a study on domestic and international black carbon emissions that shall include:

  • "an inventory of the major sources of black carbon,
  • "an assessment of the impacts of black carbon on global and regional climate,
  • "an assessment of potential metrics and approaches for quantifying the climatic effects of black carbon emissions (including its radiative forcing and warming effects) and comparing those effects to the effects of carbon dioxide and other greenhouse gases,
  • "an identification of the most cost-effective approaches to reduce black carbon emissions, and
  • "an analysis of the climatic effects and other environmental and public health benefits of those approaches."

    To fulfill the charge, EPA conducted an intensive effort to compile, assess, and summarize available scientific information on the current and future impacts of BC, and to evaluate the effectiveness of available BC mitigation approaches and technologies for protecting climate, public health, and the environment. As requested by Congress, EPA has consulted with other Federal agencies on key elements of this report, including inventories, health and climate science, and mitigation options. The report draws from recent BC assessments, including work under the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO), the Convention on Long Range Transboundary Air Pollution (CLRTAP), and the Arctic Council. Each of the individual efforts provides important information about particular sectors, regions, or issues. The task outlined for EPA by Congress is broader and more encompassing, requiring a synthesis of currently available information about BC across numerous bodies of scientific inquiry. The results are presented in the Report to Congress on Black Carbon.

    Allen Schaeffer, Executive Director of the Diesel Technology Forum (DTF), issued a statement regarding the U.S. EPA's new Report to Congress and said, "While there may still be some debate about the role of black carbon on the earth's climate, this report assures that there is no doubt about the benefits and importance of clean diesel technology in reducing black carbon emissions in the U.S. Thanks to the switch to ultra-low sulfur diesel fuel coupled with advances in diesel engine design and emissions control technology, fine particulate emissions have been virtually eliminated from new diesel vehicles and equipment in the U.S. Today diesel engines are responsible for less than six percent of all particulate emissions in the U.S. . .

    "In the past decade, emissions from heavy-duty diesel trucks and buses have been reduced by 99 percent for nitrogen oxides (NOx) -- an ozone precursor -- and 98 percent for particulate emissions which include black carbon. Today, clean diesel technology with near zero emissions is standard equipment in nearly all off-road diesel vehicles and equipment such as construction equipment, agricultural vehicles, stationary generators, locomotives and marine vehicles. Not only are the clean diesel engines near zero emissions, they are also achieving important gains in fuel efficiency of anywhere from two to 10 percent, bringing valuable savings to owners and operators of new clean diesel engines.

    "According to the report, the U.S. currently accounts for about eight percent of the global black carbon emissions, with 52 percent of that coming from mobile sources, and 93 percent of the mobile sources attributed to diesel engines. On top of the 32 percent reduction from 1990-2005, EPA projects this percentage will decline by 86 percent by 2030 'largely due to controls on new mobile diesel engines'. As clean diesel technology continues to advance, these improvements may be even more significant.

    "This report also highlights the far greater role of other sources of black carbon in developing countries such as Asia, Latin America and Africa, where residential cooking and biomass burning are the primary sources of black carbon. It also recognizes the challenges in reducing emissions from both mobile and stationary diesel engines in these developing countries since they typically do not have ready access to cleaner low sulfur fuels that are required for most advanced emissions control technologies."   

    A number of environmental groups indicated their support for the report in a joint release. Brooke Suter of the Clean Air Task Force said, "We applaud EPA's comprehensive report, the results of which underscore the need to reduce black carbon, a major component of soot, in order to protect public health and the climate. This information makes clear the need to support measures to reduce black carbon at all levels ‐‐ from funding of the Diesel Emissions Reduction Act in Congress, to Mayors and University presidents acting on climate agreements, to organizations working on climate action plans."
    Erika Rosenthal, an Earthjustice attorney said, "Science tells us that we have a limited window of opportunity to reduce emissions of black carbon and other short‐lived pollutants to slow the rate of warming and melting from the Arctic to the Andes to the Sierra, as well as to have any chance at keeping global temperature rise at 2 degrees C or less. This report give the U.S. a unique opportunity to provide greater leadership to the international community by taking action to reduce emission at home –a win‐win for public health and climate." 
    The groups indicated that internationally, United Nations Environmental Program (UNEP), the Convention on Long‐Range Transboundary Air Pollution (CLRTAP) and the Arctic Council have concluded that black carbon pollution plays a significant role in a range of climate impacts, particularly for sensitive regions such as the Arctic and high elevation mountain ranges both in and outside of the US, including increased temperatures, accelerated ice and snow melt, and disruptions to precipitation patterns.

    Access EPA's Black Carbon website for the report highlights, executive summary and full text (click here). Access the SAB Review Council website for additional background, information and meetings on the draft report (click here). Access the release from DTF (click here). Access the DTF website for more information (click here). Access a release from the environmental groups (click here). [#Air, #Climate]

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