Stay informed with free updates

Simply sign up to the Climate change myFT Digest — delivered directly to your inbox.

The Olympic Games’ challenge of cutting travel emissions is “a question that sports events should continue to ask themselves”, the top Paris 2024 green official has said, after travel caused more than half of all total emissions and raised concerns for future events.

Paris pitched this year’s Olympics as the most sustainable ever, halving the average carbon footprint of London 2012 and Rio 2016 and setting the bar for future Games hosted by Los Angeles and Brisbane.

Despite the overall success in reducing emissions, the level of travel pollution exceeded original estimates by almost 60 per cent, according to the official post-Games report. This included journeys by spectators, athletes and delegates to and within Paris and other event locations.

The greenhouse gases attributed to travel were more than 830,000 tonnes of carbon dioxide equivalent, or about 360,000 round-trip economy flights from New York to Paris.

While it invested in carbon offset projects such as distributing gas cookstoves in poor countries to replace charcoal, the Games decided not to count these towards any controversial “carbon neutral” metric.

Paris 2024 sustainability director Georgina Grenon said “people coming from New York by plane” had outstripped attempts to cut travel emissions through efforts such as cycling and public transport links between venues, a push for neighbouring national teams to arrive by train and ticket packs to encourage spectators to attend multiple events.

The average long-haul traveller produced emissions equivalent to those of 1,000 local spectators, Grenon added.

The long-haul flights of international spectators to Paris were responsible for almost a third of the Games’ total emissions, while American travellers alone contributed almost 17 per cent.

Grenon attributed the underestimation of travel emissions to record-breaking ticket sales, particularly at the last minute.

The problem of highly polluting international travel “exceeds the Olympics in general”, she said, with organisers keen to stress that the boost in travel to France was in line with global trends since the pandemic.

“We all need to be very conscious of the impact of all human activities,” said Grenon.

Experts said a disconnect remained between the traditional Olympic host city goal of record ticket sales and reducing travel emissions.

The Paris Games sold more than 12mn tickets, making at least 1mn more tickets available than for London 2012.

“I don’t see how [travel emissions] can be reduced if the model of hosting events is the same as it is now,” said David Gogishvili, a University of Lausanne senior researcher involved in a project on the climate impact of sport funded by the Swiss National Science Foundation.

Transport had been expected to account for about a third of the Paris Games’ carbon footprint but ended up accounting for 54 per cent. It remains “a problem for future Olympics”, said Benja Faecks of the not-for-profit Carbon Market Watch.

Los Angeles, where officials have pledged a “no-car” Olympics in 2028, poses a particular challenge, with less electric transport infrastructure than Paris, she noted. There is also a lack of alternatives to flying for non-local spectators travelling to Los Angeles and Brisbane in 2032.

One solution was “more geographically dispersed editions” of the Games, spread across multiple continents, Faecks said.

“The inherent nature of these [large-scale sporting] events makes them relatively unsustainable from the start,” said Walker Ross, a lecturer in sports management at the University of Edinburgh, pointing to the Olympics’ international focus and the unique geography of each host city.

Ross added that “gigantism”, as each event aimed to outdo the last, was an ongoing issue for sustainability. “It is difficult for the next city to throw a lesser party than the one before.”

“Can [the Olympics] be sustainable? No. But can they become more sustainable? Yes,” said Ross.

In total, Paris 2024 emitted greenhouse gases equivalent to 1.59mn tonnes of carbon dioxide, including from food, construction and energy use, or 54.6 per cent below the average emissions of London 2012 and Rio 2016.

The use of existing venues and focus on low-carbon materials helped organisers cut construction emissions to almost a quarter of London 2012 levels, described by Gogishvili as a “breakthrough achievement”.

In terms of emissions per athlete, also known as athletes’ carbon intensity, Paris also marked a significant decrease from previous Games, more than half London 2012’s levels.

Climate Capital

Where climate change meets business, markets and politics. Explore the FT’s coverage here.

Are you curious about the FT’s environmental sustainability commitments? Find out more about our science-based targets here