2018 Greenhouse gas inventory

We compile an annual greenhouse gas (GHG) emissions inventory that estimates the combined emissions from all sources in Washington. This estimate is based on data from the Washington Department of Commerce and the U.S. Environmental Protection Agency. 

New greenhouse gas data shows increase in 2018 state emissions

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New data on greenhouse gas emissions in Washington show that emissions rose 1.3% in 2018, reaching 99.57 million metric tons of carbon dioxide equivalent (CO2e). 

Emissions from electricity generation shrank by 2.5% from 2017 to 2018. This decline is due in part to utilities increasing investments in renewable energy, like wind and solar. Under the 2019 Clean Energy Transformation Act, Washington utilities are required to  stop using coal power by 2025, to be almost carbon neutral by 2030, and to use carbon-free, nonemitting sources of electricity by 2045.

In 2018, however, the decrease in emissions from electricity generation was offset by the increase from the transportation sector. Transporation emissions grew 3.3%, reaching 44.73 million metric tons of CO2e.

Sources of Washington greenhouse gases in 2018


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Greenhouse gas reduction limits

Gov. Jay Inslee and the Washington State Legislature have secured new policies to reduce future greenhouse gas emissions. Because our greenhouse gas emissions inventory is based on past emissions, the impact of the new policies aren't reflected in the 2018 data. Examples of steps Washington is taking to cut emissions include:

Despite the forecast for a 25% decline in emissions by 2030, Washington will still need to do more to reach the limits set by the Legislature that went into effect June 11, 2020:

  • 2020 – Emissions fall to 1990 levels of 90.5 million metric tons
  • 2030 – Emissions fall 45% below 1990 levels
  • 2040 – Emissions fall to 70% below 1990 levels
  • 2050 – Emission fall to 95% below 1990 levels – and the remaining 5% is offset.

The limits were based on scientific recommendations on what cuts are necessary to prevent the worst effects of climate change on our state’s coastlines, water supplies, forests, environment and economy.

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History of greenhouse gas emissions in Washington

Greenhouse gas emissions in Washington peaked in the year 2000, at more than 108 million metric tons. Since the Great Recession in 2008, emissions declined sharply for several years, and have since slowly climbed back up. 2018's total emissions of 99.57 million metric tons is the highest level since 2007.