While U.S. aviation has seen increased traffic in terms of passengers over the past 30 years, aviation’s share of U.S. CO₂ emissions has remained relatively constant. In 2019, civil aviation’s share of U.S. CO₂ emissions was about 2.7% of total domestic emissions.¹ Aircraft in the national air space are operating much more efficiently—moving more passengers using the same amount of energy. In 2018, the U.S aviation sector carried about 32% more passengers than in the year 2000, while using almost the same amount of fuel (and emissions), due in large part a result of the fuel efficiency improvements of the fleet over time. Today’s fleet of aircraft has an average fuel efficiency of 57.5 passenger-miles per gallon of fuel.²

[1] United States Environmental Protection Agency (EPA), “Inventory of U.S. Greenhouse Gas Emissions and Sinks,” available at: www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks, last retrieved: July 18 2021.

[2] United States, “United States Efforts to Address Aviation’s Climate Impact,” A40-WP/531, ICAO 40th General Assembly, Executive Committee, available at: www.icao.int/Meetings/a40/Documents/WP/wp_531_en.pdf, last retrieved: July 18 2021.
 

While developments in aircraft and engine technology take longer than other measures to realize their environmental benefits, significant improvements in fuel efficiency through the introduction of new and improved technologies are needed to reduce aviation’s climate impact. Major technology initiatives include:

• The Sustainable Flight National Partnership (SFNP): The National Aeronautics and Space Administration (NASA) and FAA will work with industry to accelerate the maturation of aircraft and engine technologies enabling a step-change reduction in fuel burn and CO₂ emissions beyond what industry could do alone. NASA’s investments under the SFNP include a suite of integrated, large-scale aircraft and propulsion flight and ground technology demonstrations, including ultra-efficient wings, small-core gas turbines, electrified and hybrid electric aircraft propulsion system(s), and new manufacturing techniques to enable rapid production of such new aircraft. With these technology development efforts, the SFNP will set the stage for a step-change improvement in environmental performance (i.e., 25-30% lower fuel burn and 10-15 decibel noise reduction relative to best-in-class aircraft today).

The development and deployment of SAF as a key aviation climate priority. The Administration has established a multi-agency effort to implement the “SAF Grand Challenge” to reduce cost, enhance sustainability, and expand production and use of SAF that achieves a minimum of a 50% reduction in lifecycle GHGs compared to conventional fuel. The Challenge will adopt the goal of supplying at least 3 billion gallons of SAF per year by 2030 and, by 2050, sufficient SAF to meet 100% of aviation fuel demand, projected to be around 35 billion gallons per year. The Challenge will include development of a multi-agency roadmap identifying agency roles and an implementation plan to leverage USG activities in research, development, demonstration, deployment, commercialization support, and policy in order to:

• Reduce the cost of SAF through critical activities that drive down cost of production across the supply chain; expand the feedstock and conversion technology portfolio; leverage and repurpose existing production infrastructure; reduce risk to industry; and provide incentives for production.
• Enhance sustainability of SAF by maximizing the environmental co-benefits of production; demonstrating sustainable production systems; developing low land-use change feedstock crops; reducing the carbon intensity of SAF supply chains; ensuring robust standards that guarantee environmental integrity; and, enabling approvals of higher blend levels of SAF. 
• Expand SAF supply and end use through support for regional feedstock and fuel production development and demonstration; outreach, extension, and workforce development; new infrastructure and commercialization support through federal programs; implementation of supporting policies that are enacted for SAF; enabling approvals of diverse SAF pathways; and, continued outreach and coordination with military and industry end users.

The future vision for air traffic services in the United States relies on a fully-shared information environment. Broader data distribution, information connectivity, delivery of actionable information to decision-makers, and persistent situational awareness will improve performance by distributing decisions and allowing stakeholders to best manage their operations. This will allow operators to more regularly fly their preferred, optimal trajectory, while taking full advantage of weather conditions including prevailing winds. Major operational initiatives include:

• NASA will develop a service-oriented architecture for the future NAS to deliver digitally auto negotiated operational improvements for the entire gate-to-gate flight path domain with consideration of pre- and post-flight events. In addition, technologies will be developed for identification of the most optimum high-altitude trajectory for reduced climate impacts accounting for contrail formation
• The FAA is evaluating enhancements in technology that can support reduced separation between aircraft and improved accommodation of altitude, speed, and route-change requests, thereby providing safety and efficiency benefits in oceanic Flight Information Regions.  

Continued U.S. leadership in the International Civil Aviation Organization (ICAO) including the ICAO Council, the ICAO Assembly, and the Committee on Aviation Environmental Protection (CAEP) is a fundamental cornerstone of the Administration’s efforts to mitigate aviation’s global GHG emissions. Technically feasible but ambitious international standards developed by CAEP will help reduce in-sector emissions. Major international initiatives include:

• Global implementation of the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)—the global market-based measure to address international aviation’s CO₂ emissions—and strengthening its ambition can help catalyze development and use of high-quality SAF and ensure the integrity and transparency of emission reductions from other sectors used to help bridge the gap between its in-sector emissions and its climate mitigation goals. 
• The USG also pursues bilateral technical work on aviation’s climate impact with partners around the world. The Administration will evaluate the potential for advancing efforts to address the climate crisis through these agreements.
   

Airports increasingly are aware of their GHG emissions and the need to work to mitigate these impacts. Many airports have already taken major steps to set emissions reduction targets and take action, and the FAA is taking action to support airports through several grant programs and initiatives that address GHG emissions, including:

• The Zero Emission Vehicle (ZEV) Program provides grants for any airport in the National Plan of Integrated Airport Systems to replace or convert on-road vehicles for zero-emission vehicles.
• Energy Efficiency Program provides funding for energy assessments to identify and implement energy reduction measures to reduce energy consumption across all airport operations.
• Sustainability Program provides funding for development of sustainability plans as stand-alone documents. 
   

Research to improve the understanding of non-CO₂ climate impacts of aviation is critical to better inform development of cost-beneficial solutions to address both climate impacts, as well as issues like local air quality. To enhance this research, the FAA will collaborate with other government agencies and industry stakeholders on various components of this research including evaluation of numerical weather prediction models, satellite data evaluation, aircraft campaigns, and validation methodologies. Such a comprehensive approach will be necessary to improve confidence in the usability and efficacy of this decision support tool for operational contrail mitigation.