Climate Change Regulatory Actions and Initiatives

High Global Warming Chemicals

Hydrofluorocarbons (HFCs) are fluorinated chemicals commonly used as replacements for ozone-depleting substances in applications such as air conditioning, refrigeration, fire suppression, solvents, foam blowing agents, and aerosols. HFCs are highly potent greenhouse gases with global warming potentials that can be hundreds to thousands of times greater than carbon dioxide (CO₂).

The American Innovation and Manufacturing (AIM) Act of 2020 directs EPA to address HFCs by providing new authorities to phase down the production and consumption of listed HFCs, manage these HFCs and their substitutes, and facilitate the transition to next-generation technologies that do not rely on HFCs.

On September 23, 2021, EPA issued a final rule that will phase down the U.S. production and consumption of HFCs by 85% over the next 15 years, as mandated by the AIM Act. A global phasedown of HFCs is expected to avoid up to 0.5°C of global warming by 2100.

• Learn more about HFCs, the AIM Act, and EPA regulations under AIM.

On November 3, 2022, EPA issued a proposed rule to establish the methodology for allocating HFC production and consumption allowances starting with calendar year 2024 allowances. From 2024 to 2028, HFC production and consumption allowances will be capped at 40% below the baseline (i.e., historic levels). 

Transportation/Mobile Sources

Emissions and Fuel Use Standards for New Light-Duty and Heavy-Duty Motor Vehicles

On December 20, 2021, EPA finalized federal greenhouse gas emissions standards for passenger cars and light trucks for Model Years (MY) 2023 through 2026. The final standards leverage advances in clean car technology to unlock $190 billion in net benefits to Americans, including reducing climate pollution, improving public health, and saving drivers money at the pump. These standards are the strongest vehicle emissions standards ever established for the light-duty vehicle sector, and are based on sound science and grounded in a rigorous assessment of current and future technologies. The updated standards will result in avoiding more than 3 billion tons of GHG emissions through 2050. 

These standards set the light-duty vehicle greenhouse gas program on track to provide a strong launch point for the Agency's next phase of standards for MY 2027 and beyond. EPA is planning to initiate a separate rulemaking to establish multi-pollutant emission standards under the Clean Air Act for MY 2027 and later will speed the transition of the light-duty vehicle fleet toward a zero-emissions future consistent with President Biden's Executive Order, "Strengthening American Leadership in Clean Cars and Trucks."

Learn more about the light-duty vehicle final rule.

 EPA also announced plans to reduce greenhouse gas emissions and other harmful air pollutants from heavy-duty trucks. The Agency is working on a series of major rulemakings over the next three years that would set new standards for criteria pollutants and greenhouse gas emissions for heavy-duty vehicles in MY 2027 and beyond. Taken together, these rules would set the United States on a course to achieve significant greenhouse gas and other harmful pollutant emissions reductions from highway transportation over the long term. 

Learn more about the heavy-duty trucks announcement.

Greenhouse Gas Standards for Aircraft

EPA is implementing CO₂ emission standards for airplanes used in commercial aviation and for large business jets. These standards are consistent with international standards set by the United Nations' International Civil Aviation Organization. Learn more about greenhouse gas standards for aircraft.

Renewable Fuel Standard Program

EPA is also responsible for implementing the Renewable Fuels Standard Program, a national policy that requires a certain volume of renewable fuel to replace petroleum-based transportation fuel.

Stationary Sources

Oil and Natural Gas

The oil and natural gas sector is the nation’s largest industrial source of methane, another potent greenhouse gas with a global warming potential that is 28 to 36 times greater than that of CO₂ over the first hundred years after it is emitted. EPA’s Clean Air Act protections for the oil and natural gas industry help combat climate change and reduce emissions of other harmful air pollutants, including volatile organic compounds that contribute to ground-level ozone (“smog”) and hazardous air pollutants such as benzene.

On November 2, 2021, EPA issued a proposed rule that would sharply reduce methane and other harmful air pollution from both new and existing sources in the oil and natural gas industry. The proposal would expand and strengthen emissions reduction requirements that are currently on the books for new, modified and reconstructed oil and natural gas sources, and would require states to reduce methane emissions from hundreds of thousands of existing sources nationwide for the first time.

On November 11, 2022, EPA proposed to update, strengthen, and expand the November 2021 proposal. The Agency issued a supplemental proposal that would achieve more comprehensive emissions reductions from oil and natural gas operations by improving standards in the 2021 proposal and adding proposed requirements for sources not previously covered. EPA plans to issue a final rule this year. 

Power Plants

EPA implements several health protections that affect power plants and reduce conventional air pollutants through the Acid Rain Program (ARP), the interstate air pollution transport programs, and the Mercury and Air Toxics Standards (MATS). As a result of these programs, fossil fuel-fired electric generating units reduce emissions of sulfur dioxide (SO₂), nitrogen oxides (NO_x), and hazardous air pollutants, including mercury (Hg), to protect human health and the environment—and in doing so often adopt measures that reduce CO₂ emissions as well.

Despite significant progress in reducing greenhouse gas pollution from fossil fuel-fired power plants over the last decade, the power sector is by far the largest category of stationary sources of greenhouse gases in the United States.

Carbon Pollution Standards for New and Existing Fossil Fuel-Fired Power Plans

In 2015, EPA issued a final rule establishing emission standards for greenhouse gas emissions from new fossil fuel-fired utility boilers and natural gas-fired stationary combustion turbines. Those emission limits remain in place today.

In May 2023, EPA proposed Clean Air Act emission limits and guidelines for carbon dioxide (CO₂) from fossil fuel-fired power plants based on cost-effective and available control technologies. The proposals would set limits for new gas-fired combustion turbines, existing coal, oil and gas-fired steam generating units, and certain existing gas-fired combustion turbines. 

New and Existing Municipal Solid Waste Landfills

Methane is a potent greenhouse gas. In 2016, EPA finalized two rules updating both the 1996 New Source Performance Standards (NSPS) for new and modified landfills and the 1996 guidelines for existing landfills to reduce emissions of methane-rich landfill gas. EPA issued a Federal Plan implementing the 2016 emission guidelines in May 2021. 

Greenhouse Gas Reporting

Greenhouse Gas Reporting Program

The Greenhouse Gas Reporting Program collects greenhouse gas data from large emission sources across a range of industry sectors, as well as suppliers of products that would emit greenhouse gases if released or combusted. Under the Clean Air Act (40 CFR Part 98), facilities that meet reporting thresholds must report greenhouse gas emissions to the program annually. Greenhouse gas data are available through a number of portals, including the Facility Level Information on GreenHouse gases Tool (FLIGHT).

On June 21, 2022, EPA proposed amendments to specific provisions of the GHGRP to improve the quality of the data collected under the program by addressing changes in industry practices; adopting improved calculation and monitoring methods; and collecting new data to understand new source categories or new emissions sources for specific sectors. The proposal also requested comment on potential future revisions that would expand the GHGRP to several new source categories. The comment period for these proposed amendments closed on October 6, 2022. 

Power Sector CO₂ Emissions

EPA collects detailed CO₂ emissions data and other information from power plants across the country as part of the Acid Rain Program (ARP) and the interstate air pollution transport programs. Summary-level data are updated every quarter and available on the Power Plant Emission Trends page. Power Sector Programs Progress Reports provide annual summaries of emissions and environmental impacts. More detailed emissions data are available in the Clean Air Markets Program Data (CAMPD).

Greenhouse Gas Endangerment and Cause or Contribute Findings

On December 7, 2009, EPA issued a final action under Section 202(a) of the Clean Air Act finding that six key well-mixed greenhouse gases constitute a threat to public health and welfare, and that the combined emissions from motor vehicles cause or contribute to climate change. On July 25, 2016, EPA issued a final action under Section 231(a) of the Clean Air Act finding that emissions of the six well-mixed greenhouse gases from certain classes of engines used in aircraft also constitute a threat to public health and welfare and contribute to climate change.