Moving Beyond the Status Quo [ PDF ]

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United States Regulatory Solutions for Reduction of Black Carbon Emissions

Zahava E. Essig i

The Environmental Protection Agency has the regulatory authority under the Clean Air Act to reduce black carbon emissions in the United States. Black carbon, a key particle of the soot emitted from incomplete combustion of fossil fuels and biomass, warms the atmosphere and is harmful to human health. However, there has been debate in United States courts as to whether Congress intended to address the issue of climate change when it enacted the Clean Air Act. When states, local governments, and environmental organizations petitioned the Environmental Protection Agency (EPA) in 1999 to implement regulation of carbon dioxide (CO2) and other greenhouse gases from new motor vehicles under its authority in the Clean Air Act, the agency denied the petition (ii). EPA maintained that the Act does not give the agency the authority to regulate pollutants to address climate change, and even if they did have such authority, to regulate would be unwise (iii).

Nearly eight years later, the Supreme Court answered in Massachusetts v. EPA with a 5-4 decision stating that the Clean Air Act authorizes the EPA to regulate greenhouse gases in the event the EPA Administrator forms a judgment that greenhouse gas emissions contribute to climate change (iv). The only instance where the EPA could have denied petition is if it found that greenhouse gases did not contribute to climate change (v). However, Appellate Judge Tatel noted the petitioner’s affidavit by climate scientist Michael MacCracken, which “adequately supported the conclusion that EPA's failure to curb greenhouse gas emissions contributed to the sea level rise (vi).” Since the EPA did not dispute whether greenhouse gases contribute to climate change, Justice Stevens ordered the EPA to make an endangerment finding for the climate-warming pollutants (vii).

In recent years, climate scientists have looked into additional causes of climate change. They found that black carbon degrades regional air quality and causes regional warming in and around the areas from where it is emitted (viii). Furthermore, scientists also determined that black carbon is warming the Arctic and Himalayan glaciers (ix). These findings allowed scientists to determine that black carbon is a leading cause of global warming, second only to carbon dioxide (x).

As a response to these findings, scientists commented on the omission of black carbon as a global warming pollutant in the EPA’s proposed endangerment finding for greenhouse gas emissions (xi). The EPA responded to comments posed in 2009 indicating that due to a difference in the nature and composition of black carbon when compared to greenhouse gas emissions, the uncertainty in the radiative forcing data, and the projections of global distribution of black carbon versus that of greenhouse gas emissions, black carbon deserves a separate evaluation from findings related to greenhouse gases (xii).

Although the EPA’s characterization of black carbon is correct, existing scientific data demonstrate that black carbon is warming the earth, and emissions from the United States are a contributing factor (xiii). In a post-Mass. v. EPA United States, the EPA can utilize their authority under the Clean Air Act to propose a similar endangerment finding and enact regulations to reduce black carbon emissions enough to curb its effects on climate change. The EPA can accomplish this in a number of ways:

PM2.5 Standards

Although the EPA and state environmental agencies currently regulate black carbon through the PM2.5 standard, black carbon is not specifically targeted. PM2.5 targets all particulate matter at 2.5 micrometers and less, which includes black carbon as well as other particulates that have varying effects on the environment (xiv).

Currently, EPA regulates PM2.5 at a level to reduce the direct negative health impacts, such as respiratory and cardiovascular diseases, caused by particle pollution (xv). However, the EPA does not regulate PM at a level to protect human health, safety and welfare from any known or anticipated adverse effects of climate change (xvi). The EPA should target black carbon as a global warming pollutant and regulate it at a level that reduces its effects on regional warming, as well as on snow and ice melt.

New and Existing Diesel Vehicles

In January 2001 and in June 2004, EPA issued final regulations requiring the use of ultralow sulfur diesel fuels to be used in newer on- and off-road diesel vehicles (xvii). The new low sulfur standards allow for effective use of particulate filters in diesel vehicles (xviii). Implementation of the regulations for off-road diesel vehicles began in 2007 and slowly phased in from 2008 to 2015 (xix). Particulate matter limits for on-road diesel vehicles went into effect by the 2007 model year (xx).

While the new regulations are estimated to reduce particle pollution by up to 95%, diesel emissions (both on- and off-road) remain the United States’ number one contributor of black carbon, due to continued reliance on older, high emitting diesel vehicles (xxi). In-use diesel vehicles are usually the highest emitters and could remain in use for another 20-30 years before being decommissioned. To fill this gap, the EPA has the authority to implement mandatory retrofit regulations requiring the installation of diesel particulate filters for existing diesel vehicles. A National Research Council study demonstrates that diesel retrofits are more cost effective at reducing particulate pollution than any other transportation pollution reduction strategy (xxii).

Vehicles released before the 1994 model year emit more black carbon than a diesel particulate filter can handle, overloading the filter’s carrying capacity and limiting proper filter performance (xxiii). In this instance, while the EPA cannot force retirement of these vehicles, the agency can provide tax incentives to companies and individuals who trade in their older, high emitting vehicle for a newer, low emitting one.

Agricultural burning

In the United States, agricultural burning contributes only a small fraction of global black carbon. However, agricultural burning is considerably more harmful since the emissions carry into the Arctic during the springtime when the glaciers are most vulnerable to melting (xxiv). Moreover, in the United States, agricultural burning laws vary from state to state. Some states require permits to burn while other states have no permitting process at all (xxv). The EPA can utilize their authority within the Clean Air Act to create regulations requiring states to eliminate springtime burning or eliminate agricultural burning altogether. This can be achieved by requiring states to utilize technologies that reduce crop waste, such as crop-straw gasification and biochar (xxvi).

Although EPA is wary of uncertainties in the global forcing data for black carbon, scientists have nonetheless demonstrated that black carbon has a significant warming effect, especially in regions predominated by snow and ice (xxvii). Additionally, scientists provide that reductions in black carbon emissions will produce near-term climate benefits to complement the longer-term benefits of reducing greenhouse gases. Citizens of the United States should not have to wait for lengthy governmental studies and congressional amendments to existing laws. The Clean Air Act already provides the EPA with sufficient regulatory authority to reduce black carbon emissions, bringing nearly immediate relief from the harmful effects of climate change.

References

i. Law clerk, The Climate Institute. Thanks to John-Michael Cross and Corinne Kisner for their helpful remarks. Any errors are of course mine rather than theirs. This article is a supplement to a more detailed review in a forthcoming article titled The Other Half of the Solution: A Proposal for Regulation of Black Carbon may be Necessary to Mitigate Climate Change.

ii. Massachusetts v. E.P.A., 549 U.S. 497, 513, (Sup. Ct. 2007).

iii. Id.

iv. Id. at 528

v. Id.

vi. Id. at 515.

vii. Id. at 534.

viii. V. Ramanathan and G. Carmichael, Global and regional climate changes due to black carbon, Nature Geoscience, March 23, 2008, at 221. PDF

ix. Id. at 221, 224.

x. Id. at 221.

xi. EPA, Endangerment and Cause or Contribute Findings for GHGs under Section 202(a) of the CAA, 14 May 2010.

xii. EPA, Endangerment and Cause or Contribute Findings for GHGs under Section 202(a) of the CAA: EPA’s Response to Public Comments, Vol. 9: The Endangerment Finding, 9.1.6 Addt’l Substances, 9.1.6.1: Black Carbon Comment 9-20.

xiii. Mark Z. Jacobson, Testimony for USEPA Public Hearing, Proposed Endangerment and Cause to Contribute findings for GHGs under the CAA, (May 19, 2009).

xiv. USEPA, Particulate Matter, 25 February 2010.

xv. EPA, Particulate Matter: Health and Environment, 9 May 2008.

xvi. See Clean Air Act, 42 U.S.C. §108(a)(2) (2004).

xvii. EPA, Fuels and Fuel Additives: Direct Final Rule and Notice of Proposed Rulemaking for Amendments to the Nonroad and Highway Diesel Fuel Regulations, 5 April 2010.

xviii. M. A. Bahner et. al., Use of Black Carbon and Organic Carbon Inventories for Projections and Mitigation Analysis, at 4. PDF.

xix. Id.

xx. Control of Emissions of Air Pollution from Nonroad Diesel Engines and Fuel, 69 Fed. Reg. 38,960 (June 29, 2004) (to be codified at 40 C.F.R. Pts. 9, 69, 80, 86, 89, 94, 1039, 1048, 1051, & 1068).

xxi. Id. at 38,958. See also Control of Air Pollution from new Motor Vehicles; Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements; Final Rule, 60 Fed. Reg. 5002 (Jan. 18, 2001) (to be codified at 40 C.F.R. Parts 69, 80, & 86).

xxii. Diesel Technology Forum, Why Retrofit? (last visited April 19, 2010).

xxiii. WA. St. Univ. Extension Energy Program, Diesel Particulate Filters, at 2. PDF.

xxiv. Ashley Pettus, Agricultural Activities and Arctic Climate Change: A Special CATF Report 26 (May 2009).

xxv. Id.

xxvi. Id. at 4.

xxvii. Clearing the Smoke: Understanding the Impacts of Black Carbon Pollution: Testimonial to the H. Select Comm. of Energy Independence and Global Warming, 111th Cong. (March 16, 2010) (Testimony of V. Ramanathan, Scripps Inst. Of Oceanography).

SPRING 2010 Climate Alert

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