Total greenhouse gas (GHG) emissions declined by 6.99 million metric tons of carbon dioxide equivalent (MMTCO₂e) to 418.15 MMTCO₂e in 2019, or 1.6 percent decrease compared to 2018. This also represents 2.9 percent below the 1990 level of 431 MMTCO₂e, the second largest percentage decrease since 2010.

In the last three years, California has decreased emissions by only 1.3 percent on average each year. At this rate, we’d have to reduce emissions more than threefold to hit 2030 emissions targets. At the current trajectory, the state will take significantly more time to reach the 2030 and 2050 emissions goals than it did to reach the 2020 goal. Assuming the same three-year average rate of reduction from 2017 to 2019 (-1.3%), California will reach its 2030 and 2050 goals in 2063 and 2111, respectively.

The transportation sector remains the largest-emitting sector in California by far, accounting for 40.7 percent of total included emissions in 2019 and down slightly from 40.9 percent in 2018.

GHG emissions from the commercial and residential sectors continued to climb despite an overall decreasing trend in total GHG emissions. In the five-year span from 2014 to 2019, these sectors’ share of GHG emissions rose from 4.8 percent to 5.8 percent for commercial and from 6.1 percent to 7.9 percent for residential. This is driven mainly by the continuous rise in the use of Substitutes for Ozone Depletion Substances for refrigeration and HVAC purposes, followed by fuel combustion in both the commercial and residential sectors.

So far, only the electric power sectors have seen dramatic reductions in emissions since 2000: 37.1 percent for in-state generation and more than half (-52.8%) for imports. Electric power emissions are down 1.5 percent from their 2017 levels after rising in 2018.

Slow improvements in emissions reductions are making the gap between current emissions and future goals wider. Based on the latest data, the state would need to reduce GHG emissions by 4.3 percent each year from 2019 to 2030—more than double the year-over-year reductions achieved in recent years—in order to meet the SB 32 goal by 2030. Based on last year’s data, the state would have only needed to reduce emissions by 4.1 percent from 2018 to 2030.

At the national level, the COVID-19 pandemic-induced lockdowns and the shift to work from home arrangements for a large percentage of the workforce reduced energy-related emissions from the transportation sector by 15 percent in 2020; California could expect to see a similar level of decline in transportation emissions through 2020 and into 2021 (data not yet available).

Emissions from high global warming potential substances—which mainly consist of use of substitutes for ozone-depleting substitutes (ODS) for refrigeration and air—have been trending in the wrong direction for at least two decades, increasing by 83.8 percent from 2000 (6.3 MMTCO₂e) to 2019 (11.5 MMTCO₂e).

GHG emissions per capita declined 1.8 percent from 2018 to 2019 while inflation-adjusted GDP per capita grew 3.2 percent over the same time period.

From 2008 to 2018, California’s energy intensity decreased by 27.7 percent, more than the next three most populous states: Texas (-18.8%), Florida (-13.5%) and New York (-25.6%), but behind Pennsylvania (-28.4%) and Massachusetts (-32.3%). In 2018, California’s carbon intensity was 57.1 percent of the average of the rest of the U.S.

In addition to performing well in terms of carbon intensity, California also has one of the lowest energy-related GHG emissions per capita levels, with 9.01 MTCO₂e per person in 2018, edging out every other big state except for New York (8.98 MTCO₂e per person).

After two years of decreases, the carbon intensity of California’s energy supply (CO2 relative to British thermal unit) rose 1.9 percent in 2018, more than other most populous U.S. states. Petroleum is the main source of emissions from fuel, which underscores California’s need to reduce emissions from transportation. The state also saw a reduction in hydropower as a result of drought beginning in 2018.

In 2019, within the transportation sector, GHG emissions dropped 1.9 percent from on-road vehicles (-3.00 MMTCO₂e; but most of the GHG emissions decrease came from the heavy-duty vehicles segment), but increased 3.5 percent (+0.10 MMTCO₂e) from off-road vehicles.

Despite a slight decrease in GHG emissions (-0.37 MMTCO₂e), on-road light-duty vehicles (passenger cars, light-duty trucks & SUVs, and motorcycles) accounted for 69.1 percent of the sector’s total emissions in 2019, up from 67.9 percent in 2018, due to on-road emissions from heavy-duty vehicles falling faster (-7.5%).

Californians exported or sent to landfills 42.6 million tons of waste in 2019, up 2.7 million tons compared to 2018. Meanwhile, California’s recycling rate has been falling since 2014; 2019’s recycling rate was 37 percent, down from 40 percent in 2018 and just half of the 75 percent goal for 2020. 2020’s recycling rate (data is not available yet) is expected to be even lower, as the pandemic has led to an increase in one-time use disposables.

Emissions from Substitutes for Ozone-Depleting Substances continue to increase, as they replace Ozone-Depleting Substances (ODS) being phased out under the 1987 Montreal Protocol. In 2019, GHG emissions from substitutes for ODS from all economic sectors accounted for 4.9 percent of total included statewide emissions, up from 2018’s share (4.7%) and a considerably larger share compared to 2008 (2.3%) and 2000 (1.2%).

Many types of refrigerants, most of which have very high global warming potential, are in use across various economic sectors. However, just four of them—R-32, R-125a, R-134a, and R-143a—accounted for 94.3 percent of GHG emissions from all substitutes for ozone depletion substances in 2019.

GHG emissions from fuel combustion of biogenic materials (including biofuel and other biogenic energy sources) for on-road transportation were up 216 percent in 2019 compared to 2008. Bioenergy is a source of air pollution but, encouragingly, it does necessarily lead to a net increase in global greenhouse gases.

Wildfires have been producing more GHG emissions than ever. In 2020, emissions from wildfires totaled 106.7 MMTCO₂e, more than any other economic sector except for transportation. The August Complex fire, which released an estimated 27.7 MMTCO₂e of emissions alone, is more than all the included emissions from the commercial sector (24.2 MMTCO₂e). Emissions from fires are not included in the statewide inventory as forests both serve as a source of emissions (from fires) and a sink of emissions, but increasingly wildfires present an increasing net source of emissions.