The games, which begin on Friday, are being billed as the most eco-friendly ever, thanks to pledges such as using 100 per cent renewable energy and electric vehicles.
Gold, silver and bronze Olympic medals will be made of recycled metals, podiums will be made from recycled plastic and spectators’ meals will be served in recyclable paper containers.
But conservationists have written to Japan’s prime minister Yoshihide Suga, saying the country’s “cruel and unsustainable” commercial whaling is killing some of the planet’s most important environmental guardians.
The letter, from six environmental organisations and seen by The Independent, says whales play a key role in capturing and storing harmful carbon dioxide, a greenhouse gas that is the main contributor to the climate emergency.
Signed by Humane Society International, Whale and Dolphin Conservation, Environmental Investigation Agency, Four Paws, the Animal Welfare Institute and the charity Orca, the letter explains: “One way they do this is when they feed at depth and then defecate nearer the water surface, they provide vital nutrients to the plant plankton, or phytoplankton, which grow in the sunlit upper waters,” the letter says.
“Globally, phytoplankton absorbs up to 35 per cent of all anthropogenic carbon dioxide produced.”
Whales also store tons of carbon in their bodies, so when they die and their carcasses sink to the seabed, they safely lock away on average 33 tons of carbon for hundreds of years, the letter says, calling for Japan to halt commercial whaling.
In 2019, Japan resumed the practice after failing to overturn the International Whaling Commission (IWC) ban, following decades of overfishing that had pushed whale populations to the brink of extinction.
Japan justifies its annual whale hunt in the name of “scientific whaling”, killing 331 that year. Last year’s tally was thought to be similar.
“Scientific whaling” has been condemned by both the IWC and the International Court of Justice (ICJ).
The conservation organisations warn: “We are at a pivotal moment in our global efforts to avert catastrophic climate breakdown, and high-profile, international events like the Olympics provide a vital platform to promote environmental protection.
“As one of the few countries in the world to continue to engage in the cruel and unsustainable practice of commercial whaling, Japan can’t win gold for the environment until its commitments extend into the ocean too.
“Killing whales not only causes immense animal suffering, it’s also killing some of our planet’s most important environmental guardians.”
Whales play a key role in in nurturing marine ecosystems, the writers add. “Protecting these majestic creatures isn’t just the right thing to do ethically, but is also the wise thing to do ecologically. They have intrinsic ecological value.”
Scientists say before industrial whaling began, baleen whales absorbed up to 1.9 million tonnes of carbon a year, but killing and processing whales releases carbon back into the atmosphere.
Claire Bass, UK executive director of Humane Society International, said: “These ocean leviathans play a vital role in maintaining healthy oceans and climate, and instead of blasting them with exploding harpoons, Japan should join the nations united in efforts to safeguard their populations and habitats.”
The Independent has asked the Japanese embassy in London to respond.