Reducing greenhouse gases

Washington state is a national leader in cutting greenhouse gas emissions to prevent climate change. Gov. Jay Inslee and the Washington Legislature have adopted a variety of regulations, programs, and initiatives designed to reduce greenhouse gas emissions. 

Clean Energy Transformation Act 

On May 7, 2019, Gov. Jay Inslee signed the Clean Energy Transformation Act (CETA) (SB 5116). ​The bill requires all electric utilities in Washington to transition to carbon-neutral electricity by 2030 and to 100-percent carbon-free electricity by 2045.​ The Washington Department of Commerce and the Washington Utilities and Transportation Commission (UTC) are leading the implementation efforts. 

We will assist Commerce and UTC by developing requirements for energy transformation projects, and assist utilities in measuring their progress in offsetting greenhouse gas emissions.

Building efficiency 

The energy used to heat, light, and power office buildings and other workspaces is a major source of greenhouse gas emissions. The 2019 Legislature adopted new standards that will increase the efficiency of these buildings and reduce emissions. The Legislature also increased efficiency standards for appliances.


In 2019, legislation was signed (HB 1112) to transition away from the use of hydrofluorocarbons (HFCs) beginning Jan. 1, 2020. 


Vehicle emissions are Washington's largest contributor to greenhouse gases. Under the Clean Car Law, vehicles manufactured after 2005 must meet strict emission standards to be registered, leased, rented, licensed, or sold in Washington.

Washington received $140 million from the Volkswagen federal and state settlements to reduce air pollution from transportation. We are investing these funds with a priority on transforming Washington's transportation system to advance zero-emission vehicles. 

Gov. Jay Inslee signed an executive order in 2019 requiring that 50 percent of all new passenger vehicles purchased for state fleets are electric by 2020. 

Washington state also provides up to $2,500 in sales tax incentives for residents to purchase electric vehicles, and provides funding to expand electric vehicle charging infrastructure

Greenhouse gas emissions 

Certain power plants in Washington are required to meet greenhouse gas emission standards, and offset or mitigate their carbon pollution. Learn more about this regulation on the greenhouse gas emission standard and sequestration page.

The State Agency Climate Leadership Act (RCW 70.235.050 and 060) requires some state agencies to reduce their greenhouse gas emissions. Agencies must reduce carbon pollution below 2005 levels:

  • 15 percent by 2020.
  • 36 percent by 2035.
  • 57.5 percent by 2050, or 70 percent below expected emissions that year.
Read our reports to the Governor and Legislature. 

Petroleum refinery greenhouse gas emission requirements

Oil refineries were required to reduce their greenhouse gas emissions 10 percent by 2015. If they were not able to reduce their emissions, they're required to maintain an above-average energy efficiency rating. Read more on petroleum refinery greenhouse gas emission requirements.

Reducing waste

Twenty percent of national methane emissions come from landfills. In Washington, it is estimated that seventeen percent of all garbage sent to disposal facilities is food waste. 

In 2015, the Environmental Protection Agency (EPA) and the U.S. Department of Agriculture (USDA) announced a national goal of reducing food waste 50 percent by 2030 to help combat climate change.

Washington subsequently passed legislation in 2019 (HB 1114) to reduce food waste in order to fight hunger and reduce environmental impacts.  We are working with the Departments of Agriculture and Health to develop and adopt a plan by Oct. 1, 2020, to reduce the amount of food waste by 50 percent of 2015 levels. 

Learn more about food waste prevention, recovery, and donation.

Clean Air Rule

Ecology adopted the Clean Air Rule in 2016 to address the major sources of greenhouse gases in Washington. The rule would require businesses that are responsible for large amounts of greenhouse gas emissions to cap and reduce their carbon emissions. In March 2018, Thurston County Superior Court ruled that parts of the Clean Air Rule are invalid. This means that compliance with the rule currently is suspended. On May 14, 2018, we filed an appeal with the Washington State Supreme Court.

Under a separate Ecology rule, facilities covered by the Clean Air Rule still are required to report their emissions for the Greenhouse Gas Reporting program.