First-ever US aircraft GHG emissions regulations face lawsuits

A dozen states led by California and a trio of environmental groups are separately challenging a new US regulation aimed at limiting US aircraft greenhouse gas (GHG) releases, arguing it is a rubber stamp of international aviation standards that will barely make a dent in total emissions of these pollutants.

The lawsuits come on the heels of the 11 January publication of the US Environmental Protection Agency (EPA) rule, which adopted the International Civil Aviation Organization (ICAO)'s fuel-efficiency driven carbon dioxide standard, which won't be enforced until 2028. EPA said its goal is to maintain international uniformity of aeroplane standards and allow US manufacturers of covered aeroplanes to remain competitive in the global marketplace.

But states disagree with EPA's adoption of the ICAO approach, instead of using it as a floor to seek more stringent cuts.

"The aviation industry is a significant source of greenhouse gas emissions, yet the EPA has set standards here that are the equivalent of doing nothing," California Attorney General Xavier Becerra said in a 15 January statement announcing the suit.

In a separate lawsuit, the Center for Biological Diversity (CBD) joined Friends of the Earth and the Sierra Club in sued the EPA on similar grounds as the states. They said the EPA's standards are outdated and ineffective, and lag technology by at least a decade.

Largest unregulated emissions source

Given that the aviation sector is the largest source of unregulated transportation GHGs, and the US itself is the leading GHG emitter from this source, the coalition of states is asking the US Court of Appeals for the District of Columbia Circuit to review the regulation. They are asking the DC Circuit to vacate the rule or to remand it to the agency for a rewrite.

EPA's most recent estimates, which date to 2018, show that US aircraft engaged in both domestic and international flights were responsible for 3% of total US GHG emissions of about 6.67 billion metric tons of carbon dioxide equivalent (mt of CO2e).

The states, however, noted that the US was responsible for a quarter of global GHG emissions from this sector, making it the leading emitter.

With more countries committing to net-zero carbon goals to meet the 2015 Paris Climate Agreement to reduce emissions and limit the global temperature increase to less than 2 degrees Celsius, every industry sector is being scrutinized for emissions cuts. The aviation sector is no exception; California says global GHG emissions from the sector are expected to increase threefold, and US emissions by 43% by 2050.

ICAO's aircraft engine efficiency standard was introduced in 2017 and aligned with latest available technology. In August 2020, IHS Markit termed the standard "weak" because it prevents backsliding in efficiency gains rather than driving market innovation.

Becerra filed the lawsuit on behalf of California and the state Air Resources Board. He was joined by 11 other states and the District of Columbia. Excluding Pennsylvania, the remaining states and DC also objected to the rule in a joint comment letter to EPA when the rule was proposed in August.

In that letter, the states expressed concerns that EPA's regulation violates Section 231 of the Clean Air Act, the key US law governing air pollution limits and national air quality standards. They said the law requires EPA to issue appropriate emissions standards for dangerous pollutants from aircraft engines based on a reasonable assessment of aircrafts' contribution to GHG emissions and the technological feasibility of emissions controls.

"If EPA were to adopt only what ICAO adopts, or even consider only what ICAO considers, it would fail to exercise the discretion Congress invested in it and fail its mandate to reduce pollution to the full extent practicable and necessary," the states wrote in October to EPA.

The states contend EPA acted unlawfully as well as arbitrarily and capriciously in not requiring any emissions controls beyond improving the efficiency of fuel burn.

"In fact, the EPA has not even considered any form of emission control that would reduce GHGs, despite its determination that these emissions endanger public health and the environment," the states declared 15 January.

The environmental groups are confident they will prevail in their challenge against the EPA's regulation, and that the agency will craft a new regulation based on the latest science. They said EPA began working on the rule after it lost a challenge filed by the CBD and other environmental groups in 2010. In 2016, the EPA determined that aircraft pollution drives climate change and endangers public health.

The 2019 IHS Markit study, "Reinventing the Aircraft and the Ship," suggested that while the establishment of a first aircraft engine efficiency standard was a step forward in addressing emissions, engine standards alone would be far from sufficient to meet industry GHG reduction targets.

"Engine design is just one of several pathways, there is no silver bullet in the aviation sector. We looked at operational and airspace efficiencies, different types of sustainable aviation fuels, the use of offsets…engine technology is just one of many considerations" said IHS Markit Senior Director Louise Vertz.

Vertz also observed that that California's challenge, if successful, could spur groups outside the US to question the ICAO standards.

ICAO's carbon dioxide emissions certification standard, which varies by aircraft fuselage and is based on the aircraft's performance during the cruise phase, applies to new designs starting in 2020, and existing aircraft designs in 2023, but compliance doesn't begin until 2028.

The International Council on Clean Transportation said ICAO's 10% fuel efficiency standard is no more aggressive than efficiency levels manufacturers were likely to meet without the standard in place.

Posted 18 January 2021 by Amena Saiyid, Senior Climate & Energy Research Analyst, IHS Markit