Impact of Efficiency-Driven Aircraft Technology Improvements on Climate and Air Quality

The impacts of commercial aviation on global climate and air quality have led to an industry- wide effort to reduce its environmental impact. While technological developments in aircraft propulsion, materials, and aerodynamics aim to reduce fuel consumption and CO2 emissions, these efforts often overlook the full climate and air quality impacts of aviation, especially emissions impacts of NOx, CO, HC, soot, and contrails. This paper assesses the environmental constraints associated with advancements driven by fuel efficiency by modeling aircraft technologies across narrow-body, wide-body, and regional jet categories. By focusing on near-future technology improvements in materials, aerodynamics, and propulsion, we can compute quantifiable environmental metrics such as temperature changes, global warming potentials, and monetized environmental damages. Our modeling shows that certain propulsion technologies — such as increased component polytropic efficiencies or higher allowable turbine-metal temperatures — can reduce fuel consumption by more than 10% under favorable re-optimizations of engine design. However, they often raise engine core pressures or temperatures in ways that increase NO�� emissions indices by more than 30%. This can lead to higher air quality damages, offsetting some of the CO2 benefits and in some cases result in a 2% increase in environmental damages on a total net present value (NPV) basis. Primary structure material upgrades consistently reduce both fuel burn and total NOx emissions. These improvements in air quality from reduced NOx result in a 10% reduction of the total environmental impact NPV. This analysis shows that fuel efficiency alone is an incomplete lens for understanding the environmental impact of an aircraft. By offering a quantitative assessment of how near-future upgrades can affect both climate and air quality, this paper also provides guidance on which technology paths are most effective in reducing the overall environmental impact of aviation.