Assembly Bill 32, legislation passed in California in 2006, requires the state to reduce its emissions to 1990 levels, or 431 million metric tons, by 2020. The 2016 Greenhouse Gas Emissions Inventory published July 11 shows California emitted 429 million metric tons of climate pollutants in 2016, a 3 percent drop when compared to 2015. Senate Bill 32, signed in 2016, requires the state to continue reducing GHG emissions, cutting emissions to 40 percent below 1990 levels by 2030.

According to the 2016 inventory published by CARB, carbon pollution dropped 13 percent statewide since 2004, while California’s economy grew 26 percent. Per capita emissions fell 23 percent from 2001 to 2016 and carbon pollution fell 3 percent from 2015 to 2016. The carbon intensity of California’s economy, which is the amount of carbon pollution emitted per $1 million of gross state product, dropped 38 percent between 2001 and 2016 and is now one-half of the national average.

The transportation sector was the largest source of GHG emissions in California during 2016, accounting for approximately 36 percent of California’s GHG inventory. Emissions from the sector increased 2 percent from 2015 to 2016 due to increased fuel consumption. However, CARB noted that the state also saw cars and trucks use a record 1.5 billion gallons of biofuels in 2016 under the state’s Low Carbon Fuel Standard, accounting for approximately 10 percent of the transportation fuel supply in the state. These low-carbon fuels, consisting primarily of ethanol, biodiesel and renewable diesel, avoided 14 million metric tons of carbon dioxide during the year.

CARB noted that the use of biodiesel and renewable diesel have shown tremendous growth in recent years, going from 1 percent of the total diesel blend in 2012 to 15 percent in 2016. According to the inventory, the continuously increasing market penetration of biodiesel and renewable diesel was able to offset the increase in on-road heavy-duty diesel use.