Timeline of EPA action on climate pollution

Landmarks in EPA's effort to protect human health and the environment

June 23, 2014

Supreme Court rules 7-to-2 that EPA followed the Clean Air Act correctly when they required installation of the best available control technology for large new or rebuilt industrial pollution sources of greenhouse gases that are sources of other major air pollutants.

The Court also rules that EPA must narrow its permit program to avoid applying the permitting program to many smaller sources that EPA itself had concluded would pose serious practical problems and yield relatively small pollution control benefits.

This is now the third decision in which the Supreme Court has affirmed the application of the Clean Air Act to climate pollution.


June 2, 2014

EPA unveils the Clean Power Plan. It would – for the first time – put national limits on climate pollution from power plants.


February 24, 2014

The Supreme Court hears oral arguments on the one narrow question involving the timing and tailoring rules.


October 15, 2013

The Supreme Court lets most of EPA’ s historic climate protections stand, including the Endangerment finding and the Clean Cars Standards. The Court agrees to hear one narrow question involving the timing and tailoring rules.


June 25, 2013

In a speech at Georgetown University, President Obama lays out his Climate Action Plan and outlines a timeline for EPA to regulate climate pollution from new and existing sources.


April 2013

The U.S. Supreme Court received petitions for certiorari to review the D.C. Circuit’s decision from an array of industry groups and some states.


June 26, 2012

United States Court of Appeals for the District of Columbia Circuit rules in favor of clean air protections, denying petitions against the Climate Pollution Endangerment Finding and the Clean Car Standards and dismissing petitions against the Timing and Tailoring Rules.


July 1, 2011

New sources emitting at least 100,000 tons of carbon dioxide equivalent per year and modified sources emitting at least 75,000 tons of additional carbon dioxide per year due to the modification must obtain a permit under EPA's Prevention of Significant Deterioration program and apply the best available control technology to control air pollution emissions.


January 2, 2011

Large industrial sources of greenhouse gas pollution (emitting at least 75,000 tons of carbon dioxide equivalent per year) already subject to EPA's Prevention of Significant Deterioration air permitting program begin addressing greenhouse gas emissions by deploying available, cost-effective pollution controls when applying for air permits.

Cleaner cars available for model year 2012 will save consumers an estimated $3,000 over the life of the vehicle in fuel costs, help break our oil addiction, and reduce dangerous pollution.


December 10, 2010

A D.C. Circuit panel of judges denies motions by a coalition of large emitters and the state of Texas to suspend EPA's greenhouse gas pollution reduction policies while the rules are being challenged in court. The court determines that the movants had not shown that they would be harmed by the challenged rules.


July 6, 2010

The American Chemistry Council challenges long standing EPA rules that govern when facilities must apply for permits and deploy cost-effective emissions control technologies for air pollution.


June 3, 2010

EPA issues the final Tailoring Rule providing for only the largest emitters of greenhouse gas pollution to apply for permits. The rule is challenged in the D.C. Circuit on the same day.


May 7, 2010

EPA finalizes the Vehicle Rule which establishes greenhouse gas emissions standards for new passenger vehicles model years 2012-2016. The standards are supported by the auto manufacturers, United Auto Workers, and a number of states. The standards are challenged in the D.C. Circuit on the same day.


December 15, 2009

EPA publishes the Endangerment Finding determining that six greenhouse gases endanger the public health and welfare of current and future generations. On December 23, 2009 the Endangerment Finding is challenged in the U.S. Court of Appeals in Washington, D.C. ("D.C. Circuit").


July 30, 2008

The Bush EPA issues an Advanced Notice of Proposed Rulemaking requesting public comments on how the agency should address climate pollution under the Clean Air Act.


January 31, 2008

Bush EPA Administrator Stephen Johnson transmits a letter to the President noting that the decision in Massachusetts v. EPA "combined with the latest science of climate change requires the Agency to propose a positive endangerment finding."


April 2, 2007

The U.S. Supreme Court rules in Massachusetts v. EPA that greenhouse gases are pollutants under the Clean Air Act and directs EPA to fulfill its statutory obligation to determine whether climate pollution endangers public health and welfare.


September 8, 2003

EPA reverses the Cannon legal opinion and publishes a notice denying the International Center for Technology Assessment's petition. This decision is challenged and the case moves through the courts.


October 20, 1999

The International Center for Technology Assessment and 18 other organizations file a petition with EPA requesting the agency to take action under the Clean Air Act to reduce CO2 and other climate disrupting pollutants that are released from motor vehicles.


April 10, 1998

EPA General Counsel Jonathan Cannon issues a legal opinion determining that "CO2 [carbon dioxide] emissions are within the scope of EPA's authority to regulate."