What’s the biggest event at the Olympic Games?

There’s a good case that it’s not running, or swimming, or gymnastics, but the celebration of nationhood. The opening ceremony to the 2008 Beijing Games was the most-watched event in television history. In the U.S. alone, tens of millions routinely tune in to the first night’s display. This year’s opening ceremony, beamed from Paris, the hometown of the modern Games’ founder Pierre de Coubertin, was no exception.

These parades are tremendous fun to watch. The ideal that animates them, however — that the Games belong in a single city to which athletes from across the world make pilgrimage — is looking increasingly threadbare. As the world’s demographic and economic center of gravity moves toward developing countries that will be experiencing choking summer heat by the middle of the next decade, it may become untenable.

That’s the reason for the International Olympic Committee to follow the example of other governing bodies, such as those for soccer, tennis and cricket, and give up on the idea that a premier sporting event has to be primarily held in one city.

Since its inception, hosting the Olympics has been treated as a rite of passage for cities announcing their arrival on the world stage. Early contests wound up as side events to the boosterism of the 1900 Paris Exposition Universelle and 1904 St. Louis World’s Fair. The Tokyo 1964, Seoul 1988 and Beijing 2008 Games all heralded take-off growth for their host countries.

The legacy can go the other way, though: Mexico City 1968, Montreal 1976 and Rio de Janeiro 2016 left behind debt-ridden municipalities and unsettled nations. There’s a good chance we’ll see more of that once the current round of official hosts — Los Angeles in 2028, Brisbane in 2032 — plays out.

The world’s economic center of gravity is rapidly heading east and southward. That means the audience numbers and income that support the financial outlays for the Olympics and Paralympics are moving from the rich, temperate countries that typically host the event, to increasingly tropical and middle-income locations.

Many of the Asian cities seen as strong candidates for 2036 — Ahmedabad in India, Doha in Qatar and Indonesia’s under-construction new capital city of Nusantara — are in regions subject to torrid summer temperatures that can be life-threatening to athletes. We got a foretaste of what this could mean in Tokyo in 2021, where two tennis players had to quit mid-match with heat exhaustion, and nearly 1% of athletes suffered heat-related illness.

The IOC is faced with an impossible choice. It’s promised to make future Games more environmentally and financially sustainable, repurposing existing sporting venues, even furniture in the athletes’ village, and using some creative accounting to suggest that carbon footprints have been drastically cut. At the same time, a high level of emissions is pretty much baked in when you’re flying somewhere around 30,000 athletes and officials (not to mention boats and 255 horses) into a single city.

A better idea is to follow and extend the example of soccer’s governing body FIFA, which held a joint Japan-South Korea World Cup in 2002, and is planning a U.S.-Canada-Mexico event in 2026 and a Spain-Portugal-Morocco one in 2030.

If you want to extend the Olympics to developing countries without saddling them with costly equestrian centers, rowing lakes, and sailing marinas — luxuries for minority sports, even in rich countries — then allow those events to live permanently in the largely European countries that already have the venues. Host cities can then be used primarily for the core athletic events that people care about the most.

Paris is already making a few steps in this direction with a surfing contest that’s being held 10,000 miles away in Tahiti, though it would be better to drop the event, and its super-remote location, altogether. As the climate warms, endurance events like the marathon, race walking, and road cycling — where heat stroke is the biggest risk to participants — might also have to be held where they most make sense.

Better still, you could drastically thin the number of athletes. Less than a third of competitors are in the disciplines that most people think of when they think of the Summer Games: track and field, swimming and gymnastics. Roughly the same number play ball sports. Soccer, rowing, field hockey, handball, judo, shooting, basketball and sailing will each be sending more athletes to Paris than the total number of gymnasts competing.

Many of these events have long been odd fits for the Olympics. What is one to make of a soccer contest where the U.S. outperforms Argentina, and many of the world’s most famous players aren’t even turning up? What is the point of a tennis competition, for that matter, where Novak Djokovic and Roger Federer have never won the most prestigious medal?

If future events limited athlete numbers to 5,000 (about half the current level), athletes could continue to compete in their various world championships and few viewers would even notice — but the cost, both to the climate and to city budgets, would be drastically reduced. The only way to make the Olympics more sustainable is to spread them out and make them smaller.

David Fickling is a Bloomberg Opinion columnist covering climate change and energy. Previously, he worked for Bloomberg News, the Wall Street Journal and the Financial Times.