The 2026 FIFA World Cup, co-hosted across the United States, Canada, and Mexico, is drawing record crowds and historic attendance figures — but it is also generating an unprecedented level of environmental criticism. Environmental organisations including Scientists for Global Responsibility (SGR) and the Environmental Defense Fund estimate that the tournament will produce approximately 9 million tonnes of greenhouse gas emissions, more than double the official figure reported for the 2022 Qatar World Cup. Researchers at the University of Lausanne have gone further, describing the event as leaving "the largest carbon footprint in the history of international sport."

The single largest driver of those emissions is air travel. With no extensive high-speed rail network connecting the host cities across North and Central America, teams and fans have little option but to fly between venues that can be thousands of kilometres apart. Algeria's squad, for example, has flown a round trip of roughly 4,800 kilometres between Kansas City and San Francisco; Bosnia and Herzegovina's players and supporters have had to travel more than 5,000 kilometres back and forth between Toronto, Los Angeles, and Seattle. Aviation is estimated to account for around 85% of the tournament's total carbon footprint — approximately 7.7 million of the projected 9 million tonnes.

This stands in sharp contrast to the 2024 UEFA European Championship, held in Germany, which is widely seen as a model for greener tournament management. UEFA subsidised rail travel with discounted Interrail passes, offered ticket-holders 36 hours of free local public transport, and restricted parking around stadiums. Germany's central location and well-integrated rail network made lower-carbon travel genuinely viable — options that simply do not exist at the same scale across the Americas. The 2026 World Cup has benefited from making extensive use of existing stadiums rather than building new ones, avoiding the infrastructure-heavy carbon costs that plagued Qatar, but this advantage has been largely cancelled out by the sheer volume of flights required.

The environmental impact is compounding a separate but related concern: athlete and spectator safety. A study published in the International Journal of Biometeorology found that 14 of the tournament's 16 host cities are likely to experience average wet-bulb globe temperatures — a combined measure of heat, humidity, and solar radiation — exceeding 28°C during June and July, the threshold at which the global players' union FIFpro argues matches should be suspended. These warnings proved prescient when a lightning storm forced a two-hour halt to France's group-stage match against Iraq in Philadelphia on 22 June. France coach Didier Deschamps acknowledged afterwards: "This is a safety issue — you cannot fight wind and rain and lightning. We just have to adapt."

The criticism arrives at an awkward moment for FIFA, which in 2021 pledged under the UN Sports for Climate Action Framework to cut emissions by 50% by 2030 and achieve carbon neutrality by 2040. Instead, the organisation has simultaneously announced that the 2030 World Cup — marking the centenary of the competition — will span three continents and six countries, including Spain, Portugal, and Morocco. Researchers and campaigners warn that this will dwarf even the 2026 figures. Freddie Daley, a researcher in global economic policy at the University of Sussex, called the decision deeply troubling, saying he seriously doubts FIFA can deliver such an event "in an environmentally sustainable and climate-friendly way." There is, however, growing pressure from within football's own fanbase: a survey by the UK-based football organisation Rising Ballers found that 72% of Generation Z supporters are concerned about environmental issues, with 61% calling for the sport to become greener. Whether that sentiment translates into meaningful institutional change before 2030 remains an open question.