Whales absorb high amounts of CO2 while promoting the growth of carbon-consuming phytoplankton, both of which have sparked interest in creating whale carbon credits to fight climate change and promote biodiversity. Yet, a new study questions the CO2 sequestration benefits of whales and urges not to monetize the marine animals.
The “average” whale has been valued at $2 million for CO2 capture and other services, the researchers wrote in the peer-reviewed paper published in the journal Trends in Ecology & Evolution. “We feel the scientific support for this valuation is lacking,” they said.
Currently, there are no methods to determine the total CO2 removed from the atmosphere by whales, said the research’s lead author Heidi Pearson, an associate professor of marine biology at the University of Alaska Southeast.
Carbon removal is potentially one of the whales’ many ecosystem values, she said. However, she added, the scientific evidence is still not there to link whale carbon to climate change policy and carbon credits.
In 2019, the International Monetary Fund published a study that determined a great whale’s carbon removal potential value at $2 million and calculated that the current population is worth over $1 trillion in total.
Such estimates would support the creation of incentives to protect whales from harm and increase their CO2 sequestration potential, according to a paper published by Duke University in 2020.
According to Pearson, baleen whales store an estimated 2 million metric tons of CO2 in total, or approximately the equivalent of the carbon emissions from 435,000 cars.
This is a tiny amount given the current population, Pearson told BNN Bloomberg. “Now, if we could recover whales to their pre-exploitation population abundance, then we have the potential to increase those amounts by maybe an order of magnitude.”