The Federal Aviation Administration’s Office of Environment and Energy and PARTNER have developed a simplified climate model (APMT-Impacts Climate) for use in assessing aviation environmental policies. Policy support tools like the APMT-Impacts Climate model use reduced order relationships to estimate how aviation emissions impact welfare through induced changes in temperature on a global scale. While these tools are appropriate for rapidly and efficiently modeling a suite of full-fleet policy options, they have limitations. Aviation emissions impact the climate through physical and chemical processes that can have significant spatial variation, and this heterogeneity is not captured in globally averaged models. Other factors that the current policy tool does not consider include:

• the changing atmosphere into the future — which alters the way aviation impacts the climate
• nonlinear interactions between the effects of different aviation and non-aviation emissions
• variable impact of emissions depending on altitude or latitude, such as changing flight patterns over time

This study will advance how aviation climate impacts tools inform the decision making process in aviation environmental policy. The MIT Integrated Global System Model (IGSM) is a climate model of intermediate complexity. The IGSM includes submodels of various land and sea natural systems, and a model of human activity across various relevant spatial scales. This ability to resolve interactions regionally and over time makes the IGSM a useful supplement to APMT-Impacts Climate in analyzing the impact of aviation emissions on society and the benefits of mitigation approaches such as alternative fuels or new technology. First, this project will advance the models with the most up-to-date scientific understanding. The main thrust of this study is then to develop a framework for analyzing the societal costs and benefits of aviation environmental policy using the extended modeling capability. However, with this additional capability comes the difficulty of communicating large amounts of highly technical data with significant variability and uncertainty. Thus, this project looks to develop relevant, useful and understandable metrics to communicate societal impacts of potential aviation policy scenarios to all relevant stakeholders.

ANTICIPATED OUTCOMES

• Advancement of modeling tools for policy-relevant climate impacts analyses
• Improvement of climate tools to better handle alternative fuels
• Metrics for communicating regional and hemispherical variation in impacts
• Framework for communicating a greater depth of climate impacts information

PARTICIPATING UNIVERSITY

Massachusetts Institute of Technology

LEAD INVESTIGATOR

Steven Barrett, assistant professor, Aeronautics and Astronautics, Massachusetts Institute of Technology, sbarrett@mit.edu

CO-LEAD INVESTIGATORS

Ronald Prinn, professor, Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology rprinn@mit.edu
Ian Waitz, professor, Aeronautics and Astronautics, Massachusetts Institute of Technology, iaw@mit.edu

FAA PROGRAM MANAGER

S. Daniel Jacob, Daniel.Jacob@faa.gov