Incentives such as merchandise discounts and reduced ticket prices are among the most effective ways to cut the environmental impact of “mega-events” like concert tours and  World Cups, according to University of Cambridge researchers.

The recommendation follows an analysis of Coldplay’s 2024 European tour and projections for the expanded 2026 FIFA World Cup, both of which show that audience travel is by far the largest source of carbon emissions.

Published in Communications Sustainability, the study found that Coldplay’s efforts to encourage sustainable travel — including apps comparing low-carbon transport options and merchandise discounts for fans who traveled sustainably — helped reduce travel-related emissions by 48 percent. Combined with other environmental measures, the tour’s overall carbon footprint was nearly halved, with researchers estimating that 98 percent of the emissions reductions came from changes in fan travel behavior.

The researchers estimate that the 48-team 2026 FIFA World Cup will generate approximately 4.23 million tons of carbon emissions, with 82 percent coming from spectator travel and around 3 million tons from air travel alone. Passing the full cost of offsetting those emissions directly to fans would add an average of $114 to every match ticket, the study found, making incentives to reduce travel emissions a more practical solution.

The study proposes a two-step framework for making mega-events more sustainable. First, organizers should determine whether an event’s social and economic benefits justify its climate impact. Second, responsibility for emissions should be shared, with organizers covering operational emissions while encouraging audiences to reduce indirect emissions through travel incentives, smarter venue selection and pricing strategies.

Researchers say host locations could also play a major role in reducing emissions. Around 40 percent of international attendees at the 2026 World Cup were expected to travel from Europe, meaning a European host nation would have generated substantially fewer travel emissions than North America. Other ideas include discounts for rail travel or ride sharing, carbon charges weighted toward premium tickets, and even a small broadcast fee to help fund emissions reductions.