OF ALL the decisions Paris Olympics organisers made about where to hold each sport, sending surfing competitions to the other side of the world — in the Pacific waters of Tahiti — provoked the strongest reactions. Tahitians and others railed against the building of a new viewing tower on Teahupo’o reef because of fears it would hurt marine life.

But organisers say it wasn’t just the world-class waves that lured them to the French territory 16,000 kilometres (9,942 miles) away. Paris Olympic officials had set an ambitious target of halving their overall carbon footprint compared with the 2012 London and 2016 Rio Games.

Tahiti’s surfing reef is too far offshore for fans to see the action clearly from the beach, so organisers say they calculated that most would watch on television instead of taking flights, a major source of carbon emissions.

And fewer spectators, they said, would require little new construction, another key emissions source.

“We actually did the [maths],” said Georgina Grenon, director of environmental excellence for the Paris Games. “There was less impact in Tahiti compared to other metropolitan areas.”

Tahiti’s selection provides a window into Games organisers’ approach to hitting their goal of reducing emissions, the driver of climate change. It also underscores an inherent tension in the drive for sustainability: There are trade-offs, and reducing emissions doesn’t necessarily mean preserving the environment.

Organisers’ goal is to limit emissions to 1.58 million metric tons of CO2 equivalent for the July 26 to August 11 Games and Paralympics that follow. That’s still a lot of pollution — equal to that of about 1.3 million economy passengers flying one way from New York to Paris on Boeing 787 jets, according to myclimate, a climate and sustainability consultancy.

It’s a lot less, however, than the footprint of previous Games.

Organisers say they’re thinking about the Games’ future, not just the planet’s. Fewer cities are volunteering to spend billions on infrastructure that sometimes falls into disuse. Paris and the next host, Los Angeles in 2028, were the only cities left in the race when picked in 2017. For organisers, hosting less wasteful Games is key, along with including more inclusive, youth-oriented events such as skateboarding.

Paris is under additional pressure to be a sustainable model: the city hosted the 2015 UN climate talks that resulted in the Paris Agreement, the most significant international climate accord to date. Delegates agreed the world should limit average global temperature rise to 2 degrees Celsius (3.6° Fahrenheit) above that of the 1850s, and ideally cap it at 1.5°C (2.7°F) — a goal looking increasingly unattainable.

Independent experts say Paris appears to be decarbonising in the systematic ways businesses do: calculate total emissions, then start cutting, including myriad small CO2 savings that add up significantly. Organisers targeted reductions across three categories: construction, transportation and operations.

“They seem to be taking a very thoughtful approach,” said Adam Braun of Clarasight, which builds carbon-planning software for companies. “They are trying to do something that is indicative of how many organisations will be holding themselves accountable.”

The biggest break from previous Games is in construction. Organisers say 95 per cent of facilities are existing or will be temporary. Two new structures were deemed unavoidable: the Olympic Village, to house athletes and later become housing and office space, and the aquatics centre in Paris’s disadvantaged northern suburbs.

Using wood, low-carbon cement, and salvaged materials helped reduce emissions by 30 per cent compared with traditional methods, Grenon said.

Reductions in operations include food. The average meal in France — restaurant or home-prepared — produces about 2 kilograms (4.4 pounds) of CO2, said Philipp Wurz, the Games’ catering head. Paris aims to halve that by sourcing 80 per cent of ingredients locally, cutting transport emissions, and offering spectators 60 per cent plant-based food options.

Winning minds as well as tastebuds could take work. “Locally grown food, and supporting local farmers, are beautiful things,” tennis player Victoria Azarenka said. But “when people are doing these big gestures, I’m not fully convinced of the impact,” she added of Paris’s overall climate efforts.

Another emissions-savings source is energy. Energy will represent only 1 per cent of emissions, organisers said. They intend to use 100 per cent renewable power from wind and solar farms, plus solar panels on some venues.

Stadiums and temporary venues will get power from the grid instead of diesel generators, which produce a vast amount of CO2. Giant electrical plugs at venues will remain post-Games, removing the need for generators at future events.

Reducing transportation-related emissions is arguably Paris’s biggest challenge. Tourism officials expect 15.3 million visitors for the Olympics and Paralympics, including 1.9 million from outside France, with at least 850,000 taking long-haul flights.

In Paris, there are low-carbon transport options — cycling routes, Metro trains, buses and other public transit — to all venues.

But the inability to control how people get to the Olympics, or any big event, raises questions about whether humanity can afford such get-togethers at the cost of further climate damage.

“Maybe things like the Olympics have to be reconsidered,” said Seth Warren Rose of the Eneref Institute, an advocacy and research group focused on sustainable development. “Having millions of people congregate in a single area is a very intensive thing.”

Rose said organisers’ efforts are laudable, but they should have gone further — reducing emissions beyond half and finding more ways to make sustainability a central part of the fan experience.

Some critics have also questioned some sponsors. Air France, ports operator CMA CGM Group and metals giant ArcelorMittal are leaders in carbon-intensive industries. On their websites, all tout their Olympic sponsorship and sustainability efforts.

The Upright Project, a Finnish company that creates and analyses data to evaluate companies’ impact on the world, looked at sponsors, assigning scores for positive and negative impacts on environment, health, jobs and other metrics.

On environment, sponsors’ emissions had an overall six-fold negative impact.

“I do find the current sustainability discourse, where we effectively celebrate companies’ miniscule sustainability tweaks and greenwashing efforts like they actually make a difference to climate change, extremely harmful,” Upright Project’s Annu Nieminen said in a statement. “If the Paris 2024 sponsors are celebrated by the organisers for their ‘sustainability,’ that’s contributing to the same harmful discourse.”

In a statement, organisers said the Games presented “a unique opportunity to encourage partner businesses to adopt more responsible practices.”

For emissions it can’t cut, Paris plans to compensate – a practice called offsetting. Planting trees, for example, could help take CO2 out of the atmosphere that the Games put in. But offset markets aren’t well regulated, and investigations by news organisations have found some projects to be fraudulent while others miscalculated the quantity of emissions captured.

Organisers say they’ll continue to adapt sustainability plans as they go, including those in Tahiti. The metal judging tower, which replaced the ageing wooden one Tahiti previously used to host surfing competitions, was scaled back in size in response to concerns about environmental harm, organisers say. Finished earlier this year, the tower will be dismantled after the Games. It will be erected and used again when Teahupo’o holds world surfing events.

Organisers say they expect about 1,300 people with Olympic accreditation on the island, including 500 flying in. That total, likely much smaller than if the competition took place off France’s coast, includes surfers, judges, journalists and Games workers.

“We say that sustainability is a collective sport,” Grenon said. “Will everything be perfect? No, right? We cannot say that. We’re still working very, very hard to go as far as we can.”