By Eleanor Revelle (LWVIL and LWVUS Climate Change Task Force Member)

With the demise of cap-and-trade legislation during the 2010 session of Congress, the climate action spotlight has shifted to the Environmental Protection Agency (EPA) and the Clean Air Act (CAA). But efforts are now underway to block EPA regulation of greenhouse gas (GHG) emissions.

Clean Air Act of 1970

In the aftermath of the first Earth Day in April 1970, Congress passed the Clean Air Act and created the EPA to implement the new law. Over the 40 years that the CAA has been in effect, it has yielded dramatic public health and environmental benefits. 

CAA programs have achieved major reductions in dangerous air pollutants that cause smog, acid rain, and lead poisoning. The EPA reports that this has prevented hundreds of thousands of premature deaths, has helped millions avoid developing respiratory ailments and heart disease, and (by banning leaded gasoline) has greatly reduced the incidence of low child IQ.

The benefits of these advances have far exceeded the costs of compliance. An EPA analysis of the CAA's first 20 years found that the dollar value of the human health and environmental benefits amounted to more than 40 times the costs of regulation. For the 1990-2010 period, as requirements have become more stringent, the EPA estimates a benefit-to-cost ratio of four to one.

At the same time, CAA programs spurred significant growth in the U.S. environmental technologies industry. By 2007, the industry was generating $282 billion in revenues, producing $40 billion in exports, and supporting 1.6 million jobs. Innovations include catalytic converters, scrubbers, and low-VOC paints and consumer products.

U.S. Supreme Court Ruling

Despite these achievements, concerns about global warming pollution led Massachusetts and 11 other states to sue the EPA over its failure to regulate GHG emissions from the transportation sector. They charged that human-influenced global climate change was causing adverse effects, such as sea-level rise, to the state of Massachusetts. 

In a 5-4 decision in April 2007, the U.S. Supreme Court ruled that carbon dioxide and other GHGs meet the definition of "air pollutants" under the CAA. The Court directed the EPA to determine whether or not GHG emissions from new motor vehicles (the sector cited in the lawsuit) cause or contribute to air pollution that may endanger the public health or welfare.

In 2009, the EPA responded by conducting an extensive examination of the scientific evidence and, in December 2009, made a determination — the "endangerment finding" — that GHG concentrations in the atmosphere do threaten the public health and welfare of current and future generations. The EPA also found that GHG emissions from new motor vehicles contribute to the atmospheric concentration of these gases and, thus, to the threat from climate change.

Once the EPA had issued its endangerment finding, the agency moved ahead to finalize proposed GHG emissions standards for light-duty motor vehicles.

The Clean Cars Rule

The EPA partnered with the Department of Transportation (DOT) to set increasingly stringent standards for GHG emissions and fuel efficiency for passenger cars and light-duty trucks for model years 2012-2016.

The federal rules mirror California's Clean Car Standards, also adopted by 13 other states, and set a target of 35.5 miles per gallon (mpg) for 2016 model-year vehicles. The auto industry welcomed the uniform national standards.

The new standards surpass the 2007 federal fuel economy law, which required an average fuel economy of 35 mpg in 2020. The EPA estimates that the new rules will cut GHG emissions by 960 million metric tons over the regulated vehicles' lifetime, equivalent to taking 50 million cars and light trucks off the road in 2030. Consumers can expect to save $3,000 over the lifetime of a model-year 2016 vehicle.

The EPA and DOT have since proposed emissions and fuel efficiency standards for heavy-duty trucks and buses, beginning in the 2014 model year, and will also set further standards for light-duty vehicles for model years 2017 and beyond.

Stationary Source Regulations

The EPA is also phasing in regulations for major stationary sources of GHG emissions (e.g., power plants, industrial facilities). As of January 2, 2011, rules requiring new or substantially modified facilities to obtain permits that address their GHG emissions have begun to take effect. These facilities must make use of "best available control technologies" to minimize GHG emissions.

The EPA has taken steps to ensure that the new rules do not affect small stationary sources, such as small businesses and farms, schools, or churches. CAA permitting requirements apply to facilities that emit more than 100-250 tons/year of a regulated pollutant such as lead, sulfur dioxide, and nitrogen dioxide. But GHGs are emitted in much higher volumes than these pollutants.

The EPA, therefore, issued a "tailoring rule" that raises the threshold for GHG emissions so that only the largest sources would be subject to the permitting requirements. The thresholds for GHG emissions are 75,000-100,000 tons/year.

In addition, the EPA has established a timeline for setting limits on GHG emissions for both new and existing power plants and oil refineries. The EPA will propose new rules for power plants in July 2011 and for refineries in December 2011. Final rules for power plants will be issued in May 2012 and for refineries in November 2012. Together, power plants and refineries account for about 40 percent of all U.S. GHG emissions

Challenges to EPA Regulations

Opponents of the new rules are working to block or delay EPA regulation of GHG emissions. Several dozen legal challenges to EPA's recent actions have been filed by a variety of business and industry groups and by several states and members of Congress.

In Congress, bills have been introduced that would, for example, amend the CAA to exclude regulation of GHGs, limit the use of EPA funds, and delay regulation of GHG emissions for two years.

The League of Women Voters strongly opposes efforts such as these to undermine the EPA's ability to establish the urgently needed clean air protections called for by the CAA. It's time for action -- time to reduce dangerous global warming pollution and safeguard "the public health and welfare of current and future generations."

For more details, see the Clean Air Defense section of the LWVUS Toolkit for Climate Action (

Produced by the LWVUS Climate Change Task Force
© 2011 by the League of Women Voters of the United States

voterready_cleanair.pdf25.49 KB