Clean Air Act
The Attorney General has played a leading role in forcing the federal government to regulate greenhouse gas emissions under the federal Clean Air Act. As a result of numerous lawsuits, petitions and comment letters filed by California and other states and environmental groups, the federal government has taken significant steps to deal with climate change.
In April, 2007, in a case brought by Massachusetts, California and other states, the U.S. Supreme Court ruled that greenhouse gases were "air pollutants" and that the U.S. Environmental Protection Agency (EPA) had to determine whether to regulate these emissions from cars and light trucks under the Clean Air Act. Read the Supreme Court’s decision. 
[PDF 354 kb / 66 pg]
Unfortunately, the Bush Administration failed to make the required determination in the next two years, despite repeated requests from California and other states to do so. In July 2008, EPA issued an "Advanced Notice of Public Rulemaking" that discussed various options for regulation under the Clean Air Act, but EPA declined to take any action. In November, 2008, the Attorney General, together with 21 other states, environmental agencies and cities, submitted a letter to EPA urging it to promptly regulate greenhouse gases under the Act. Read the group letter.
[PDF 30 kb / 5 pg] The Attorney General also submitted a more detailed comment letter. Read the Attorney General's letter
[PDF 192 kb / 30 pg] and attachments.
[PDF 966 kb / 48 pg]
In April, 2009, EPA issued a proposed determination finding that global warming is endangering public health and welfare and that emissions from cars and light trucks are contributing to global warming. The Attorney General joined comments
[PDF 4 mb / 7 pg] submitted by other states and also submitted California-specific comments.
[PDF 33 kb / 3 pg] EPA issued a final "endangerment" determination in December, 2009. Numerous groups have filed challenges to this determination; the Attorney General has intervened with 17 other states to defend EPA's determination.
On April 1, 2010, EPA and the Department of Transportation's National Highway Traffic Safety Administration (NHTSA) issued a joint rule under the Clean Air Act and the Energy Policy and Conservation Act to reduce greenhouse gas emissions and improve fuel economy for new cars and trucks. The joint standards will require an average fuel economy standard of 35.5 miles per gallon (mpg) in 2016. The rule implements the national agreement reached by California, the federal government, and the auto industry in 2009 that harmonizes the federal government's standards and California's standards. See Clean Cars. Numerous industry groups filed suit challenging the rule. The Attorney General, along with 13 other states, the Governor, the California Air Resources Board, and New York City, have intervened in the case in support of EPA.
Regulation of Vessels, Aircraft, and Non-Road Vehicles
In 2007 and 2008, the Attorney General filed petitions with EPA requesting that it adopt regulations under the Clean Air Act controlling the greenhouse gas emissions from ocean-going vessels, aircraft, and non-road vehicles and engines (such as construction and farm machinery, mining equipment, lawn and garden equipment and others).
Together, these sources emit as much greenhouse gas as 270 million cars, more than the entire number of registered vehicles in the United States. Ocean-going vessels are responsible for 2-3% of worldwide greenhouse gas emissions. Aircraft contribute 3% of the United States carbon dioxide emissions and 12% of our transportation sector emissions. Non-road vehicles and engines emitted 220 million tons of carbon dioxide in 2007. Read the ocean-going vessel petition. [PDF 1.1 mb / 17 pg] Read the aircraft petition. [PDF 1.4 mb / 22 pg] Read the non-road vehicle petition. [PDF 1.4 mb / 22 pg] Because the Bush Administration
EPA failed to respond to any of these petitions or otherwise take any action to regulate greenhouse gases from any sources, the Attorney General and other states sent a formal notification to EPA that it would sue EPA for unreasonable delay if it did not act on the petitions. Read the notice letter. [PDF 2.1 mb / 13 pg]
Mandatory Reporting Rule
Pursuant to a directive from Congress, in 2009, EPA issued a reporting rule requiring that large sources of greenhouse gas emissions submit annual reports of their emissions to EPA. Numerous industry and other groups filed suit challenging the rule. The Attorney General intervened with ten other states to defend the rule.
Coal-Fired Power Plants and Other Industrial Sources
The Attorney General, along with the attorneys general of several other states, also has sent comment letters about proposed coal-fired power plants. The plants, slated to use traditional coal-burning technology, are projected to each emit millions of tons of carbon dioxide per year. The letters urged the state permitting agencies to examine alternative energy sources and require the plants, if it they receive a permit, to be constructed with more efficient and less polluting Integrated Gasification Combined Cycle (IGCC) technology. Read the letters. In March, 2009, the Attorney General joined seven other state attorneys general in filing comments with EPA's regional office about a massive (1,500 megawatt) coal-fired power plant proposed in New Mexico, which is expected to emit 12-13 million metric tons of carbon dioxide annually. Read the letter.
[PDF 53 kb / 9 pg]
The Attorney General, along with the attorneys general of several other states, submitted comments to the Bush Administration EPA protesting its failure to propose rules under the Clean Air Act regulating carbon dioxide emissions from Portland cement plants. Read the Portland cement plants comment letter. [PDF 42 kb / 8 pg]
On September 9, 2010, EPA finalized the cement plant rule, but did not set new source performance standards for greenhouse gases. Sierra Club and Natural Resources Defense Council petitioned the U.S. Court of Appeals for the District of Columbia Circuit for judicial review. On January 19, 2011, the district court granted the motion of California, Washington, and Oregon to intervene in that challenge, which is currently pending.
The Attorney General, along with the attorneys general of several other states, similarly challenged the failure of the Bush Administration EPA to regulate carbon dioxide emissions from electric power generating units (power plants) – the largest source category of greenhouse gas emissions in the nation. On March 2, 2011, the challengers reached a groundbreaking settlement with EPA. The settlement requires EPA to propose regulations to control carbon dioxide emissions from new power plants, and to issue guidelines for control of carbon dioxide emissions from existing power plants. Pursuant to the settlement, EPA will issue the proposed regulations by the end of July of 2011, will take public comments on the proposed rules, and will adopt final, binding regulations by May 26, 2012. Read the power plant settlement [PDF 479 kb / 21 pg]
The Attorney General also has taken steps to force EPA to require modern pollution control technology (known as "best available control technology") when power plants, refineries and other large industrial sources receive a permit to be constructed or rebuilt. In 2008, the Attorney General joined a friend-of-the court brief ("amicus" brief) filed with EPA’s Environmental Appeals Board by the New York Attorney General and four other states arguing that EPA should require such controls under the Clean Air Act. Read the brief.
[PDF 529 kb / 27 pg] The Appeals Board sustained the challenge and ordered EPA to reconsider its position that it lacked authority to impose such controls. Read the order.
[PDF 622 kb / 69 pg]
In response to the decision, EPA issued a memo taking the position that it could not require controls for industrial sources until emissions limitations for greenhouse gases are enacted under other provisions of the Clean Air Act. EPA since adopted such controls -- greenhouse gas regulations for motor vehicles that take effect in 2011 (noted above) -- and as a result EPA will begin requiring controls for industrial sources at that time.
EPA's "Tailoring Rule"
EPA developed a program for regulating industrial and other stationary sources under the Clean Air Act. As part of this program, EPA has adopted a so-called "tailoring" rule, a regulation that sets forth which facilities will be required to obtain permits and implement pollution controls for greenhouse gas emissions and in what timeframe. The Attorney General filed a comment letter on the draft tailoring rule. Read the letter.
[PDF 45 kb / 6 pg] EPA adopted the final rule in May, 2010. Read the rule. Numerous industry groups filed suit challenging the rule. The California Attorney General joined twelve other states in seeking to intervene in the case to support EPA's rule.