The California Air Resources Board (CARB) announced that greenhouse gas emissions in California in 2016 fell below 1990 levels for the first time since emissions peaked in 2004—a reduction roughly equivalent to taking 12 million cars off the road or saving 6 billion gallons of gasoline a year.

Under Assembly Bill 32 passed in 2006, California must reduce its emissions to 1990 levels (431 million metric tons) by 2020. The state’s latest Greenhouse Gas Emissions Inventory shows that California emitted 429 million metric tons of climate pollutants in 2016—a drop of 12 million metric tons, or three percent, from 2015.

Senate Bill 32, signed in 2016, requires the state to go even further than AB 32 and cut greenhouse gas emissions 40% below 1990 levels by 2030—the most ambitious carbon goal in North America.

Highlights from the newly published inventory include:

• Greenhouse gas emissions dropped 13% statewide since a 2004 peak while the economy grew 26%.

• Per capita emissions continue to be among the lowest in the country. They fell 23% from a peak of 14 metric tons per person (roughly equal to driving 34,000 miles) in 2001 to 10.8 metric tons per person in 2016 (roughly equal to driving 26,000 miles). That is approximately half as much as the national average.

• The carbon intensity of California’s economy has dropped 38% since the 2001 peak and is now one-half the national average. In other words, California now produces twice as many goods and services for the same amount of greenhouse gas emissions as the rest of the nation.

Electricity generation had the largest decline among the sectors. Emissions from this sector declined 18% in 2016, reflecting continued growth in renewable energy—such as solar, wind and geothermal—as a result of the state’s Renewables Portfolio Standard, and a corresponding drop in natural gas generation. Solar electricity in all forms, including rooftop generation, grew 33%, while natural gas fell more than 15%.

Due to the carbon price signal created by the Cap-and-Trade Program that makes fossil fuel generation more expensive, cleaner out-of-state electricity is increasingly taking the place of fuels such as coal. This included more imports of hydroelectric power from outside the state, which grew by nearly 39% in 2016 thanks to abundant rainfall throughout the West Coast.

Emissions may vary from year-to-year depending on the weather and other factors. However, this inventory demonstrates that our policies are working to incentivize GHG-free energy sources and ensure the state remains on track to meet its climate targets in 2020 and beyond.

—CARB Executive Officer Richard Corey

The transportation sector, the state’s largest source of greenhouse gases, saw a 2% increase in emissions in 2016 because of increased fuel consumption. But the state also saw cars and trucks use a record amount of biofuels—1.5 billion gallons in all—as a result of the state’s Low Carbon Fuel Standard.

These low-carbon alternative fuels, consisting mostly of biodiesel, renewable diesel, and ethanol, avoided 14 million metric tons of carbon dioxide from entering the atmosphere, compared to what would have happened if conventional fossil fuels had been used.

Emissions from the industrial sector—including refineries, oil and gas extraction, cement plants, and other stationary sources—fell 2% from 2015 levels, though emissions from refineries increased slightly.

California’s primary programs for reducing greenhouse gases to 1990 levels by 2020 are the Renewables Portfolio Standard; the Advanced Clean Cars Program; the Low Carbon Fuel Standard; and the Cap-and-Trade Program. Additional programs address a variety of greenhouse gas sources. These include the Short-Lived Climate Pollutants Strategy, the Sustainable Communities Strategy and the Sustainable Freight Action Plan.

The 2030 Scoping Plan, adopted by CARB last year, lays out how these initiatives work together to reduce greenhouse gases to achieve California’s 2030 target of 260 million metric tons and also to reduce smog-causing pollutants. This ambitious target will require California to more than double the rate at which it has been cutting climate-changing gases.

How the inventory is compiled. The annual statewide GHG emissions inventory is compiled using many data sources. The primary source is data directly reported to CARB by the largest facilities and companies under the Cap-and-Trade Program. These reports are verified by a CARB-accredited third-party verification body.

CARB also relies on statistical data from various state and federal government agencies in developing the statewide inventory. These agencies include the California Board of Equalization, Energy Commission, Department of Food and Agriculture and CalRecycle, as well as the US Environmental Protection Agency, Department of Energy, Department of Agriculture, and US Geological Survey.

The greenhouse gas emission numbers above are stated in million metric tons of carbon dioxide equivalent (CO₂e).