Tracking greenhouse gases
Washington has science-based limits on greenhouse gas emissions to help prevent the worst effects of climate change on our environment and economy. By law, we must reduce the state’s total emissions through 2050:
- 2020 – reduce to 1990 levels
- 2030 – 45% below 1990 levels
- 2040 – 70% below 1990 levels
- 2050 – 95% below 1990 levels/net zero emissions
Lawmakers enacted a suite of policies to achieve these limits, and Ecology tracks statewide emissions to measure our progress using two tools:
- The greenhouse gas inventory – an annual report that estimates Washington’s total emissions using many different datasets
- Large emitter data – annual greenhouse gas data directly from Washington’s largest emitters
The inventory vs. Large emitter data
The greenhouse gas inventory compiles many different datasets from every sector of the economy into a single statewide total. It’s our official tool for gauging whether we’re meeting our climate limits.
In anticipation of the state’s major climate policies taking effect, Ecology also began collecting data directly from all of Washington’s largest greenhouse gas emitters in 2022. This data accounts for the majority of Washington’s emissions, so it’s a valuable leading indicator of the statewide total in our inventories.
Because it requires many different data sources that become available on different schedules, the inventory lags more than the large emitter data. Washington’s most recent greenhouse gas inventory goes through 2022, and our large emitter data goes through 2024.
What does the data tell us about Washington’s emissions?
Our state’s total emissions peaked more than a quarter-century ago in 2000. Since then, the state’s emissions have been trending downward, despite fluctuating over the years. Between 2000 and 2022, Washington’s emissions fell 12.4%. In that same time, the state's population grew by a third and gross domestic product nearly doubled.
The most recent inventory shows the state’s total emissions declined 0.5% from 2021 to 2022 due to declines in coal- and natural gas-based power generation, higher wind and solar production, and more hydropower generation.
Data from large emitters shows the downward trend may have continued through at least 2024. Washington’s largest emitters posted a 0.45% decrease from 2023 to 2024 that was also driven by clean electricity. The official totals for 2023 and 2024 will be confirmed in future inventories.
Greenhouse gas emissions from large emitters, including covered emissions from CCA-covered entities
To learn more about statewide emissions, including sector-level trends, visit our inventory webpage.
To learn more about the data we collect from large emitters, visit our mandatory greenhouse gas reporting for large emitters page.