September 9, 2015
According to the most recent EPA Greenhouse Gas Inventory Report (2014), transportation produces only four percent less GhGs than the largest emitter, electricity production. While we can alter climate change outcomes by purchasing more fuel-efficient vehicles, the efforts of the Environmental Protection Agency and National Highway Traffic Safety Administration bring those those fuel-efficient vehicles into existence.
Here is a brief history of the action taken by the US government to improve fuel economy of vehicles sold in the US.
1970: Clean Air Act (EPA)
Reduce smog by regulating six pollutants from mobile and stationary sources with emissions and air quality standards. Did not originally account for greenhouse gasses, but included language entailing government responsibility to curb any emissions that threaten public health
1975: Energy Policy and Conservation Act, Corporate Average Fuel Economy (NHTSA)
Intended to reduce energy consumption by increasing the fuel economy of cars and light trucks in response to the oil embargo and resulting price shocks in the early 1970s. New passenger cars have to double the average fuel economy between model years 1978 and 1985 to 27.5 mpg and light trucks have to increase fuel economy to 22.2 mpg between 1978 and 2007. In both cases the final vehicle fleet goals are sales-weighted and accomplished gradually through annual fuel economy marks.
2007 (April) Supreme Court – Massachusetts v. EPA
Ruling: Greenhouse gases threaten public health, therefore the EPA can set greenhouse gas emissions standards for vehicles under the Clean Air Act.
2007 (December)- Energy Independence and Security Act (NHSTA)
Raises CAFE standards of American-made cars, light trucks, and SUVs by 40 percent to a combined average of 35 mpg by 2020. Also sets requirements for increased biofuel production and provides research grants to states with low production levels.
2009 (April) Unified National Program
Harmonizes standards of National Highway Traffic Safety Administration, EPA and California Air Resources Board with National Program. This way, the EPA can set ghg emissions standards under the Clean Air Act and the NHTSA can establish Corporate Average Fuel Economy (CAFE) standards under the Energy Policy and Conservation Act, as amended by the Energy Independence and Security Act.
Note: Under the unified program standards are set in emissions by grams of CO2 per mile by the EPA and miles per gallon by the NHTSA. Here, fuel economies described in mpg are portrayed as if the emissions standards were accomplished entirely by fuel efficiency improvements.
2010 (April) National Program Standards Phase I (Light-Duty)
New standards for passenger cars, light-duty trucks, and medium-duty passenger vehicles model years 2012-16 are set to a fleet-wide average of 35.5 mpg by 2016. The first 200,000 plug-in hybrids and electric vehicles receive a zero gram per mile CO2 emissions value in compliance calculations¹.
2011 (August) National Program Standards Phase I (Heavy Duty)
Sets Medium and Heavy Duty Vehicles fuel efficiency and tailpipe emissions standards estimated to reduce CO2 emissions by about 270 million metric tons and save about 530 million barrels of oil over the life of the vehicles built in model years 2014-2018.
2012 (August) National Program Standards Phase II (Light-Duty)
Sets Light-Duty Vehicle Fuel Efficiency Standards to a fleet-wide average of 54.5 mpg for passenger cars, light-duty trucks and medium-duty passenger vehicles, by model year 2025. These standards are projected to save drivers upwards of $1.7 trillion and curb emissions by 6 billion metric tons. Plug-in hybrids and electric vehicles sold will be counted as multiple vehicles in their manufacturer’s compliance calculations.
The results of fuel economy standards are clear: a profusion of fuel-efficient cars and trucks, and hybrid and electric vehicles. What can we do to help? Enjoy the fruits of this effort and buy cars that save money and emit less!
1. For PHEVs, the zero gram per mile value applies only to the percentage of miles driven on grid electricity
Photo Credit: Flickr: U.S. Department of Agriculture, Richard Masoner / Cyclelicious, Per-Olof Forsberg
Chart Credit: NHTSA