Scientists attribute World Cup heat to climate change

Scientists link North American heat wave to climate change

A team of researchers concluded on 3 July 2026 that the heat and humidity afflicting the northeastern United States and eastern Canada this week would have been “virtually impossible” without human-caused climate change. The findings, reported by The New York Times, come from World Weather Attribution, a scientific collaboration that rapidly evaluates extreme weather to determine how much global warming influenced it. The New York Times article, written by climate and environmental reporter Raymond Zhong, did not address heat in other regions, focusing on the heat dome now being examined by attribution scientists.

Methodology and key finding

To estimate how much climate change increased the likelihood of this week’s conditions, the scientists analyzed records of wet bulb globe temperature (WBGT), a metric that accounts for humidity, wind and direct sunlight, according to The New York Times. Because the heat wave was still unfolding when the analysis was prepared, the researchers combined historical weather observations with forecast data. They found that the highest five-day average WBGT over the northeastern United States and eastern Canada remains rare in today’s climate, with roughly a 0.5 percent chance of occurring in any given year. In the cooler pre-industrial climate, the same conditions would have been so rare as to be effectively impossible, the researchers concluded.

The New York Times notes that the team’s findings have not yet been published in a peer-reviewed journal, a standard caveat for World Weather Attribution’s rapid analyses. The group previously analyzed a heat wave in Western Europe in June and concluded that climate change had fueled that event as well.

Direct link to the World Cup

Reuters published its own article on the same day with the headline “Climate change behind sweltering World Cup, scientists say.” The full text was not accessible for verification, but the headline and URL indicate the Reuters report framed the attribution findings in the context of the 2026 World Cup, which is being co-hosted by the United States, Canada and Mexico and whose matches are scheduled through 19 July 2026. Readers should note that the specific claims attributed to Reuters could not be confirmed from the supplied excerpt.

A climate scientist’s framing

Theodore Keeping, a climate scientist at Imperial College London who worked on the attribution analysis, told The New York Times: “On America’s 250th birthday, our study gives a clear reality check. The climate the country has today is fundamentally different to the one it had when the founding fathers signed the Declaration of Independence.” The July 4 timing of his remark refers to the United States’ semiquincentennial.

Europe has been baking in parallel

While the World Weather Attribution team examined North America, a separate BBC analysis published in early July documented a parallel pattern of record-breaking heat across Europe. The BBC reported that June 2026 saw temperature records “not only broken but smashed in what the UN’s weather agency called an ‘extraordinary’ event across the continent.” Stephen Belcher, chief scientist at the UK Met Office, told the BBC: “Human-induced climate change has made events like this more likely and more intense.”

Specific European records cited

According to the BBC, temperatures in the United Kingdom peaked at 37.7 °C in Lingwood, Norfolk, surpassing the country’s previous June high of 35.6 °C, set in 1957 and tied in 1976. In Cardiff, the overnight low of 23.5 °C on the night of 24–25 June was the warmest June night ever recorded around the United Kingdom. More than a dozen European countries broke their June temperature records, with gaps of up to two or three degrees between old and new highs. France and Spain recorded their hottest June days in terms of national average, and Switzerland reached 39 °C, exceeding the previous June record by more than 2 °C, the BBC reported.

Why Europe is warming quickly

The BBC outlined several mechanisms behind Europe’s rapid warming. The continent is warming faster than the global average in part because of the loss of bright snow and ice, which once reflected more solar energy back to space, and because of a decline in tiny polluting aerosols in the air that had a similar reflective effect. Some scientists argue that changes in atmospheric circulation patterns are also bringing more of the high-pressure systems that produce heatwaves, though the BBC noted this link is not certain. Sonia Seneviratne, a professor at the Institute for Atmospheric and Climate Science at ETH Zurich in Switzerland, told the BBC: “Compared to historical measurements, this was obviously very unusual,” while adding that as a climate scientist she was “not that surprised” given a warming climate.

Tropical nights and the role of humidity

The BBC’s reporting emphasized that humidity compounds the danger of extreme heat because it impairs the body’s ability to cool through sweating. The UK’s warmest June night on record, in Cardiff, illustrated a trend the BBC described as increasingly common: “tropical nights,” during which temperatures remain above 20 °C. Ed Hawkins, professor of climate science at the University of Reading, told the BBC: “We would definitely expect to see more and more tropical nights, as global temperatures keep rising.”

Two events, two analytical frameworks

The North American attribution analysis and the BBC’s European review are separate efforts with different methodologies. World Weather Attribution produces quantitative estimates of how climate change altered an event’s likelihood, drawing on observational data and climate models. The BBC’s reporting draws on national meteorological agencies (the Met Office, Deutscher Wetterdienst, Météo-France) and on interviews with individual scientists rather than a single rapid attribution study. The European heat wave in late June was, however, the subject of a separate World Weather Attribution analysis that reached similar conclusions about climate change’s role, according to The New York Times.

What is confirmed and what remains unverified

Confirmed from the available sources: the World Weather Attribution finding that this week’s North American heat wave would have been “virtually impossible” without climate change; the WBGT-based methodology; the roughly 0.5 percent annual likelihood in today’s climate; and the parallel record-breaking European heat documented by the BBC and national weather agencies. Not confirmed: any specific details from the Reuters article beyond its headline and topic, including which World Cup venues or matches were directly discussed. Readers seeking the Reuters account should consult the original at the URL provided.

Broader public health context

Beyond sporting events, the convergence of two major heat waves in a single summer has implications documented in the wider scientific literature. A review published in Nature titled “Waterborne diseases and climate change,” cited by the Global Burden of Disease studies and the IPCC Sixth Assessment, outlines how rising temperatures, changing precipitation and more frequent extreme events can affect the transmission of diarrheal diseases and other infections. While that Nature article was not directly referenced in the heat wave coverage, it provides context for the public-health stakes of a warming climate that go well beyond heat-stroke risk during a football tournament.

What to watch next

The World Weather Attribution analysis has not yet appeared in a peer-reviewed journal, so a formal publication is a near-term milestone to watch. On the sporting side, Reuters’ headline implies a connection between the heat and the 2026 World Cup, and any response from FIFA, tournament organizers or participating federations on heat-mitigation protocols — including cooling breaks, kickoff-time adjustments or venue changes — would be a significant follow-up. On the European side, the BBC reported that another heat wave was already on the way in early July, and updated assessments from the Met Office and the World Meteorological Organization are expected as the month progresses.