London: Scientists have said that a century of whaling may have released more than 100 million tonnes of carbon dioxide (CO2) into the atmosphere.
Whales store carbon within their huge bodies and when they are killed, much of this carbon can be released.
According to report, US scientists revealed their estimate of carbon released by whaling at a major ocean sciences meeting in the US.
Dr Andrew Pershing from the University of Maine described whales as the “forests of the ocean”.
Dr Pershing and his colleagues from the Gulf of Maine Research Institute calculated the annual carbon-storing capacity of whales as they grew.
“Whales, like any animal or plant on the planet, are made out of a lot of carbon,” he said.
“And when you kill and remove a whale from the ocean, that’s removing carbon from this storage system and possibly sending it into the atmosphere,” he added.
In their initial calculations, the team worked out that 100 years of whaling had released an amount of carbon equivalent to burning 130,000 sq km of temperate forests, or to driving 128,000 Humvees continuously for 100 years.
Dr Pershing stressed that this was still a relatively tiny amount when compared to the billions of tonnes produced by human activity every year.
But he said that whales played an important role in storing and transporting carbon in the marine ecosystem.
Simply leaving large groups of whales to grow could “sequester” the greenhouse gas, in amounts that were comparable to some of the reforestation schemes that earn and sell carbon credits.
He suggested that a similar system of carbon credits could be applied to whales in order to protect and rebuild their stocks.
“The idea would be to do a full accounting of how much carbon you could store in a fully populated stock of fish or whales, and allow countries to sell their fish quota as carbon credits,” he explained.
“You could use those credits as an incentive to reduce the fishing pressure or to promote the conservation of some of these species,” he said.