It’s been a big week for aviation. The solar-powered plane Solar Impulse 2 officially completed its historic flight around the world on Tuesday without using any fossil fuels, just a day after EPA took the first steps toward regulating aircraft greenhouse gas emissions in the United States.
On July 25, the U.S. Environmental Protection Agency (EPA) released its endangerment finding for aircraft, indicating that greenhouse gas emissions from aircraft are hazardous to public health. This finding requires the EPA to begin crafting regulations for aircraft emissions, including carbon dioxide, methane, nitrous oxides (NOx), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride.
Sky-High Emissions from U.S Aircraft
Emissions from U.S. aircraft account for three percent of national greenhouse gas emissions and 12 percent of emissions from the U.S. transportation sector. After the industrial sector, transportation produces the most greenhouse gas emissions in the United States (26 percent in 2014), and that percentage is growing faster than any other sector. While the aircraft industry has taken steps to increase fuel efficiency and use of alternative fuels, namely biofuels, the Federal Aviation Administration estimates U.S. aviation emissions will rise by 100 percent by 2050 under a “business-as-usual” scenario, due primarily to increases in air travel.
The new endangerment finding has been in the works since 2007, when EPA received an official petition to create aircraft emissions regulations. Several environmental groups then sued the EPA in 2010 to require aircraft emissions regulations. A federal court then ruled in 2011 that the EPA was required under the Clean Air Act to evaluate the effects of aircraft emissions on human health. In response, EPA submitted a proposed endangerment finding in 2015, but the finding wasn’t finalized.
Several of the same environmental groups, including Friends of the Earth, the Center for Biological Diversity, and Earthjustice, again sued the EPA in April 2016, arguing an “unreasonable delay” in issuing a finalized endangerment finding. Vera Pardee of the Center for Biological Diversity said, “Airplanes’ skyrocketing climate pollution requires urgent action, not more food dragging from the Obama administration.” Following the April lawsuit, EPA sent a draft endangerment finding to the White House in May.
Monday’s finalized endangerment finding has sparked debate between the airline industry and environmental groups over the feasibility of stringent regulations. Many airlines are pushing the EPA to work within the international standards that have been proposed, rather than building on them. Vaughn Jennings of Airlines for America said, “As aviation is a global industry… it is critical that aircraft emissions standards be set at the international level and not imposed unilaterally by one country or set of countries.” Nancy Young, also of Airlines for America, said that when it comes to aircraft efficiency, “We’re already at the edge of feasibility.”
Global Efforts to Curb Emissions
Future U.S. regulations would be part of the global effort to reduce aircraft emissions. In February of this year, the International Civil Aviation Organization (ICAO), a working group of the United Nations’ Committee on Aviation Environmental Protection (CAEP), announced the first ever binding standards for aviation emissions, in the form of a carbon dioxide (CO2) cap and fuel efficiency standard.
The CAEP standards mandate an overall 4 percent reduction in cruising fuel consumption across the industry by 2028, compared with 2016 levels. Actual reductions will range from 0 to 11 percent. If the standards are adopted, all new aircraft designs starting in 2020, and new planes in operation by 2023, must comply. Existing aircraft are exempt from the CAEP regulation.
The U.S. airline industry embraced the CAEP efforts, considering it a complement to its own voluntary commitment to improve fuel efficiency by 1.5 percent annually through 2020, with carbon-neutral growth from 2020 onwards. The Airlines for America's vice president for environmental affairs, Nancy Young, called the standards ambitious. However, many environmental groups feel that these standards don’t go far enough to curb emissions. Sarah Burt from Earthjustice said, “…the standards [President Obama] is prepared to accept for carbon pollution from airplanes are embarrassingly low.”
Cutting Carbon through Biofuels
The new endangerment finding could be good news for the biofuel sector. Aircraft are difficult to decarbonize, since they require energy-dense fuels. While strides in electric and hybrid jets have made progress, it’s assumed that liquid fuels will be required for aircraft for the foreseeable future. As airlines look to decarbonize their fuel sources, biofuels are the natural choice, especially in the context of new regulation.
A recent Department of Energy (DOE) report on reducing airplane emissions identifies sustainable jet fuels as one of four key areas of focus. The report says that using sustainable fuel options could reduce emissions of harmful substances like sulfur oxides (SOx) and particulate matter (PM) as well as reducing greenhouse gas emissions.
Biofuels are also a key part of airlines’ voluntary efforts to reduce emissions. Airlines in the global trade group International Air Transport Association (IATA) has set a goal of cutting 2005 level emissions 50 percent between 2020 and 2050. This goal is expected to be met primarily through the increased use of sustainable biofuel. IATA has said that the use of biofuels in aircraft, compared to traditional jet fuel, could reduce CO2 lifecycle emissions by up to 80 percent.
Regulations Going Forward
The global level CAEP standards are expected to be adopted by the full organization early next year at the March meeting. EPA said in a press release that it will pursue standards that are “at least as stringent,” potentially going beyond those of the CAEP. Any standards that EPA puts forth will be open for public comment before they are finalized.
Author: Rebecca Chillrud
For more information see:
- EPA Determines that Aircraft Emissions Contribute to Climate Change Endangering Public Health and the Environment, Environmental Protection Agency
- Next Item on Obama’s Climate Agenda: Airplane Pollution, The New York Times
- EPA Advances Plans to Limit Carbon Emissions from Aircraft, The Wall Street Journal
- Lawsuit Challenges Obama Administration's Failure to Curb Airplane Carbon Pollution, Center for Biological Diversity
- EPA Sends Aircraft Greenhouse Gas Rule to White House, Law 360
- Groups Sue EPA to Force Airplane Air Pollution Rules, Environmental Leader
- In Historic Move, Aviation Emissions to Be Regulated Globally, EESI
- DOE Issues Report on Reducing Commercial Aviation GHG Emissions, Biomass Magazine