New research shows international sports events could significantly reduce their carbon footprint - if fewer event staff attend in person.
Professor James Higham from the University of Otago's Department of Tourism contributed to a study which found CO2 emissions at the 2020 Olympics Games in Tokyo were significantly lower, due to fewer event-related personnel attending because of the Covid-19 pandemic.
It meant fewer International Olympic Committee officials including referees and judges, media, and marketing partners attended the games.
As a result, the Tokyo 2020 Olympic Games was a unique case study to investigate the impact of reduced international travel on event CO2 emissions.
The study, led by Dr Eiji Ito, from Chukyo University, did not include the greatly reduced number of spectators that would normally have visited Japan for the Olympic Games.
It indicated around 30,200 officials personnel from other countries at the Olympics, significantly fewer than the 141,000 originally expected.
This reduced international air travel emissions by 129,686 tonnes of CO2.
"Our results indicate that acting to reduce the number of event-related personnel attending the Olympics is an important strategy that aims to mitigate the carbon footprint of mega sports events."
Higham said he was not suggesting future events should be held in empty stadiums, but that small changes could make an impact.
"We need to challenge ourselves to decarbonise these types of sports events."
Future events should model their emissions and explore ways that event design and delivery could contribute to event emissions reductions.
This could include sourcing local/ regional officials, offering opportunities for live virtual reality streaming and online press conferences, and ensuring that all unavoidable event-related emissions were costed.
Sponsors could be challenged to declare their event-related emissions to harness their commitment to a low carbon event.
To determine the emissions reduction of the recent Olympics, researchers identified the number of people visiting Japan with temporary visitor visas in July last year. They then subtracted the number of Olympic athletes, followed by the visitors to Japan in June to account for non-Olympics related visa-holders.
"We estimated the return flight distance [miles] and CO2 emissions (kg) per passenger between the main and hub airports of each country and region and Narita International Airport using a flight carbon calculator."
The results were calculated by multiplying the number of inbound international Olympics-related personnel by the air travel carbon emissions per passenger for each country and region.
"It shows that there is enormous potential to reduce the carbon footprint of the Olympic Games in terms of transportation and people travelling internationally to be in attendance."