National Center for Sustainable Transportation

This study explores the potential to promote lower-emissions air travel by providing consumers with information about the carbon emissions of alternative flight choices in the context of online flight search and booking. Researchers surveyed over 450 UC Davis faculty, researchers, and staff, asking them to choose among hypothetical flight options for university-related business trips. Emissions estimates for flight alternatives were prominently displayed alongside cost, layovers and airport, and the lowest-emissions flight was labeled “Greenest Flight”. The researchers found an impressive rate of willingness to pay for lower-emissions flights: around $200/ton of CO₂E saved, a magnitude higher than that seen in carbon offsets programs. They also found that displaying carbon information encouraged Davis employees to choose nonstop (lower-emissions) flights, when available, from a more distant airport over indirect flights from their preferred airport for medium-distance flights. In a second step of analysis, they estimated the carbon and cost impacts for UC Davis business travel if the university were to adopt a flight-search interface that prioritizes carbon emissions information and displays alternatives from multiple regional airports in their employee travel-booking portal. Based on the choice models from the survey data, a year’s worth of actual employee air travel data, and data collected on flight alternatives with respect to the flights chosen by employees, they estimated potential annual savings of more than 79 tons of CO₂E, and a more impressive $56,000 reduction in airfare costs, due to an increased willingness of travelers to take advantage of cheaper (often nonstop) flight options out of SFO. Broader university policies encouraging lower-emissions flights and enhanced public transportation within the multi-airport mega-region would likely support much greater carbon savings. Institutionalizing this “nudge” within organizations with large travel budgets, like the UC system, could have an industry-wide impact in aviation.

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