Climate Change Limits Future Host Cities for Summer Olympics

Lancet commentary by COEH authors Kirk Smith and John Balmes suggests that by 2085, only eight of 543 cities outside of Western Europe will likely have summer temperatures cool enough to safely host the Summer Olympics. In North America the list includes only three cities – San Francisco, Calgary, and Vancouver.

The authors considered cities to be in this low-risk category if summer temperatures are projected to be less than to 26 degrees Celsius (°C) or 78.8 degrees Fahrenheit in the shade, a safe temperature to run the marathon, an endurance event the researchers used as safety benchmark for other Olympic competitions. In 2016, only about 70 percent of elite competitors in the US Olympic Team Trials Marathon could finish their race where peak temperatures reached 25.6 degrees Celsius, The Lancet commentary notes.

Lifting the limit to 28°C, a medium-risk safety threshold established by the authors, means a total of 41 cities would be considered viable. “Projections out to the early 22nd century, which carry even more uncertainty, suggest the last cities in the northern hemisphere with low-risk conditions for the games will be Belfast, Dublin, Edinburgh, and Glasgow,” the authors conclude.

Athletes are prone to heat stress in outdoor endurance events, but so are outdoor workers in agriculture and construction, the authors point out. And because more than half the world’s population works outdoors, the projected rise in temperatures due to climate change points to a bigger problem – the geographic expansion of regions in which heavy outdoor work is no longer safe for a greater part of the year.

The findings published in the Lancet exploded in the media in August 2016. Coming in the middle of the Rio Games, the story received worldwide coverage – at least 100 stories in media plus coverage by some 1500 radio and TV stations in North America.

The commentary by Smith and Balmes included, among others, co-authors Alistair Woodward from the University of Auckland, and Cindy Chang, an associate professor of Sports Medicine at UCSF who also works as a sports medicine specialist and team physician for UC Berkeley intercollegiate athletes, including for the London Olympics in 2012.

back to top