Academics, activists and athletes are shining a spotlight on the Olympics’ potential climate impact as the competition kicks off in Paris.

Organisers said Paris 2024 would be the “greenest ever” Games, working alongside its sponsors towards economic, social and environmental responsibility.

But researchers have warned that ice usage during summer Games has reached “extraordinary levels”.

The report published in the British Journal of Sports Medicine said: “Beyond the financial implications for the local organising committee, this raises environmental concerns, as ice provision requires water and considerable amounts of energy for production and storage.”

Paris 2024 estimated demand for 650 tonnes of ice for uses like cryotherapy, ice baths, compression pumps and treating heatstroke, according to the paper.

This is more than 10 times the some 64 tonnes delivered during the Tokyo 2020 games.

The researchers also warned that ice is often used to obtain benefits that are not evidence-based, potentially impairing recovery.

“When planning for the provision of ice, organisers should aim to minimise the use of non evidence-based practices and promote better sustainability,” the report added.

Paris 2024 has also been facing criticism over sponsorship deals, with campaigners claiming the firms’ environmental impact is at odds with the International Olympic Committee’s wider sustainability efforts.

This week, protesters replaced billboards in Paris and five other major French cities with mock adverts highlighting Olympics sponsor Toyota as a high-emitting company.

Posters were installed in bus stop ad spaces this week in an action co-ordinated by the Brandalism collective and Paris-based Resistance a l’Agression Publicitaire (RAP).

One read: “Toyota: Proud to be the Highest Polluting Sponsor for the Olympics” and another read: “Art belongs in Paris. Giant polluters do not.”

Sonnie Bird from Brandalism said: “As Olympians in Paris go faster, higher and stronger, Toyota keeps getting dirtier, deadlier and more polluting.

“With Toyota as a sponsor, the Paris Olympics will leave a legacy not of gold, silver and bronze but of pollution.”

Olympic champion cyclist Chris Boardman also arrived in Paris earlier this week as part of an eight-day bike ride from Manchester to raise awareness about the effects of climate change.

The British athlete, who won gold in the men’s individual pursuit cycling at the 1992 Olympics in Barcelona, said: “We’ve had all the weather – torrential rain going over the Peak District on day one, through to scorching and intense heat and above average temperatures – we’ve done climate change in a week.”

During the 550-mile ride, Mr Boardman visited different sports clubs leading the way on sustainability, including plans to be net zero by 2029 or gathering volunteers to do conservation work and litter picking.

“The point of the ride was not just to highlight the issue of climate change and its impact on sport but also to give people hope,” he said.

“All the projects we visited along the route have shown that we can do this, we can do it together and sport is perfectly placed to lead that change.”

Last month, leading athletes and climate scientists from the University of Portsmouth warned that intense heat at the Paris games could lead to competitors collapsing and in worst-case scenarios dying.

Temperatures have remained high this year after 2023 marked the warmest year globally on record.

Wildlife group WWF warned that this is not a record that nations want to break ahead of the Games kicking off on Friday.

Isabella O’Dowd, WWF-UK’s head of climate policy, said: “This record-breaking year has delivered a stark and clear warning from the planet about the direction we’re heading in. But we all have the power to change that.

“As we come together to cheer on our athletes to break records at the Olympics, it’s important to remember the power of our collective voice, which we can use to call on the new UK Government to show real leadership, especially at this year’s climate and nature summits.”

The PA news agency has contacted Paris 2024 and Toyota for comment.