Washington's greenhouse gas inventory

The greenhouse gas inventory is the historical record of Washington’s contribution to global climate change. It estimates statewide emissions and measures emissions reductions compared to a 1990 baseline. This helps policymakers track progress toward meeting our state's emission reduction limits.

As required by law, we publish an inventory report every two years. The next inventory will be published by December 2024 and include emissions through 2021. Our inventories are mostly based on data from the Environmental Protection Agency (EPA), and we expect shorter lag times in the future as we develop the ability to collect these data ourselves.

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Greenhouse gas inventories

Ecology data shows that Washington's greenhouse gas emissions increased the past three years:

2019 total emissions — 102.1 million metric tons
2018 total emissions — 95.5 million metric tons
2017 total emissions — 95.3 million metric tons

Current inventory
Past inventories

Washington State Greenhouse Gas Emissions Inventory: 1990–2019

2019 Washington greenhouse gases: 25% heating, 39% transportation, 21% electricity, 14% other — **2019 greenhouse gas sources, by sector**

Greenhouse gas emissions for 2018 – 2019

New data on Washington's greenhouse gas emissions show emissions rose almost 7% in 2019 from 2018, reaching 102.1 million metric tons (MMT) of carbon dioxide equivalent (CO₂e).

Transportation remains the largest contributor of greenhouse gas emissions in Washington showing a slight increase from 2018 to 2019 of less than 3%, or 4.8 MMT, reaching 40.3 MMT of CO₂e. Overall, transportation's share of statewide emissions dropped from 44.9% in 2018 to 39% in 2019 while the share from the electricity sector increased.

Emissions from electricity generation grew almost 33% from 2018 to 2019. The greatest contributor to the 2018–2019 emissions increase is the mix of fuels used in the electricity sector. This sector’s emissions rose from 16.5 MMT CO₂e in 2018 to 21.9 MMT CO₂e in 2019, an increase of 5.4 MMT CO₂e.

This year’s rise is in response to reduced availability of hydropower generation and a corresponding increase in fossil fuel generation to meet demand. However, 2020 data is available for the electricity sector. It shows that 2020 emissions in this sector fell 35% to 14.2 MMT CO₂e. This is 16% below the 1990 level (16.9 MMT CO₂e) for this sector.

Sources of Washington greenhouse gases in 2019

Transportation was the largest category of greenhouse gas emissions in Washington during 2019. This category includes emissions from on-road gasoline and diesel vehicles, marine vessels, jet fuel and aviation gasoline, railroads, and natural gas used in transportation. Emissions from on-road gasoline — personal cars and trucks — make up over half of total emissions in this category.

• 39.5% of total Washington emissions
• 40.3 million metric tons of emissions

Learn more about how we’re helping reduce greenhouse gases from transportation.

Emissions in this sector come from burning fuels for heating homes and workplaces, and energy used by industries. This category includes heat generated from coal, natural gas, and oil.

• 25% of total Washington emissions
• 25.3 million metric tons of emissions

Learn more about how we’re helping reduce greenhouse gases from residential, commercial, and industrial heating.

Worldwide, electricity generation is the largest source of carbon emissions, but the category comes in third in Washington. This category includes emissions from power generated from coal, natural gas, petroleum, and waste.

• 21% of total Washington emissions
• 21.9 million metric tons of emissions

Learn more about how we’re helping reduce greenhouse gases from electricity generation.

Agriculture — 6.2 million metric tons

Agricultural activities such as manure management, fertilizer use, and livestock digestion (enteric fermentation) result in methane and nitrous oxide emissions, which are measured in this category.

• 6.1% of total Washington emissions
• 6.2 million metric tons of emissions

Industrial processes — 5.3 million metric tons

This sector includes greenhouse gas emissions from industry-specific processes such as aluminum or cement manufacturing, or fugitive emissions such as sulfur hexafluoride (SF6) released from electric power transmission and distribution systems.

• 5.2% of total Washington emissions
• 5.3 million metric tons of emissions

Waste management — 2.4 million metric tons

This sector includes greenhouse gas emissions from landfills and wastewater treatment facilities.

• 2.4% of total Washington emissions
• 2.4 million metric tons of emissions

Natural gas distribution — 0.7 million metric tons

This sector includes fugitive greenhouse gas emissions that are released during distribution of fossil fuels. These emissions are typically fugitive methane due to leakage and venting from natural gas pipelines.

• <1% of total Washington emissions
• 0.7 million metric tons of emissions

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 2019 data. Examples of steps Washington is taking to cut emissions include:

Switching the state to 100% clean electricity by 2045
Raising standards for building energy efficiency
Advancing zero emission vehicles

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 93.5 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 about what cuts are necessary to prevent the worst effects of climate change on our state’s coastlines, water supplies, forests, environment, and economy.

graph showing actual emissions and future goals from 1990 to present

2020 greenhouse gas limits

The next update of this report will determine whether Washington will meet the 2020 greenhouse gas emissions limit, which requires total emissions to match what they were in 1990 at 93.5 million metric tons.

Although it is too soon to determine whether Washington will meet this limit, the effects of the COVID-19 pandemic are expected to significantly reduce emissions in 2020. However, these reductions are not expected to last as our state and nation recover from the pandemic.

Additional analysis

Projections from the Rhodium Group (a national research firm experienced at evaluating energy and climate policies) found that by 2030, greenhouse gas emissions in Washington will drop by as much as 25%. Their predictions are based on existing policies and do not account for emission reductions due to the economic effects of the COVID-19 pandemic.

History of greenhouse gas emissions in Washington

Greenhouse gas emissions in Washington peaked in 1999, at just over 111 million metric tons. Since the Great Recession in 2008, emissions declined sharply for several years and have since slowly climbed back up. 2019's total emissions of 102.1 million metric tons are the highest level since 2007.

Contact information

Caroline Halter

Communications Manager

Caroline.Halter@ecy.wa.gov

564-669-8947