(Bloomberg) -- Whales, scientists have discovered, are climate warriors, absorbing huge amounts of carbon dioxide in their gargantuan bodies while pooping in such great quantities as to stimulate the growth of other CO2-consuming organisms in the ocean. That has sparked interest from the IMF and others in creating whale carbon credits or other financial mechanisms that could finance the fight against climate change and biodiversity loss. In a new paper, however, the scientists behind that carbon research deliver a message: Don’t monetize the whales.
“Recent attempts to monetize whales have garnered attention by valuing an ‘average’ whale at $2 million for carbon-capture and other services,” the scientists wrote in the peer-reviewed study published Thursday in the journal Trends in Ecology & Evolution. “As the authors of several foundational papers cited in these reports, we feel the scientific support for this valuation is lacking.”
The paper was released as representatives of 191 countries convene this week in Montreal at COP15, a United Nations-sponsored meeting to negotiate an agreement to protect global biodiversity. Among the attendees at the Convention on Biological Diversity conference are financial institutions interested in “biocredits,” which like carbon credits would allow corporations to meet ESG goals by financing biodiversity preservation. As with carbon credits, there is concern that biocredits could allow companies to greenwash their role in biodiversity loss unless the offsets are based on sound science.
There are accepted protocols to measure and verify, for instance, the volume of CO2 sequestered by a redwood tree. There are no current methods, though, to determine the total carbon dioxide removed from the atmosphere by whales’ life cycle as they traverse the ocean, according to Heidi Pearson, lead author of the paper and an associate professor of marine biology at the University of Alaska Southeast.
“Whales have many ecosystem values, carbon removal potentially being one of them,” Pearson said. “But the state of the science is still in its infancy and not ready to make that leap from whale carbon to climate change policy, and even further afield, talking about carbon credits, which is leaps and bounds down the road.”
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That hasn’t deterred efforts to place a dollar value on whales. The goal is to multiply whales’ carbon sequestration potential by promoting a restoration of the marine mammals to levels that existed before industrial whaling decimated their populations.
The International Monetary Fund in 2019 published a paper that proposed assigning a value of $2 million for each great whale to account for their role in carbon removal, calculating that the current population of the marine mammals is worth more than $1 trillion.
In a follow-up paper released by Duke University in 2020, the lead author of the IMF study, Ralph Chami, and his colleagues focused on eight whale species found off the coasts of Brazil and Chile. In addition to the carbon contained in their bodies, the valuation included estimates of the whales’ contribution to eco-tourism and fisheries. The largest part of their worth derived from whale excrement’s role in promoting the growth of phytoplankton, tiny creatures that are the basis of the marine food web and absorb an estimated 37 billion metric tons of CO2 annually.
Chami, an assistant director in the IMF’s Institute for Capacity Development, and his co-authors determined values for whales ranging from $691,634 for a sei whale to $4 million for a Chilean blue whale, the planet’s largest animal. The average value across the eight species was around $2 million.
Valuations like those would allow the creation of incentives to avoid harming whales so their populations and carbon removal potential could expand, according to the authors of the Duke paper. “For example, a ship that strikes and kills a blue whale off the coast of Brazil should be fined the full value of the whale, or $3.6 million,” they note.
Pearson said that the science is largely settled when it comes to calculating the amount of carbon absorbed by whales and then sequestered on the seabed when they die and sink to the ocean floor. The new paper calculates that the world’s current population of baleen whales stores an estimated 2 million metric tons of carbon, while their “whale falls” sequester 60,000 metric tons. That 2 million metric tons of CO2 is roughly equivalent to the carbon emissions from 435,000 cars.
“It's a minuscule amount based on the current population," Pearson said. “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.”
But she also noted that the giant animals’ role in phytoplankton production and the larger ocean carbon cycle is exceedingly complicated, varies by region and remains to be quantified. “Whales’ ability to stimulate phytoplankton growth and suck up CO2 is a potentially really big carbon benefit, but we are very uncertain on that pathway,” Pearson said.
Chami said he understands scientists’ concerns, but the climate crisis demands action. “We are at a point in history when we need to move from focusing on localized impacts to broader climate/nature policy and financing,” he said in an email. “In the case of whales, we can use minimum estimates, as we did, and give uncertainty ranges - just as we do for any investment product.”
“We simply don’t have the time to get it 100% right, unless we are willing to silently witness the death of not only the whales, but risk our own existence,” Chami added.
Andrew Pershing, a co-author of the new paper, is a marine scientist whose research over a decade ago calculated whales’ potential to sequester carbon. He first called for the creation of whale carbon credits in 2010, but warns that nothing should be done prematurely.
“It was a long, long time ago and I would say that there's a lot of work that you have to do to get something to the level of verifiability you need for carbon credits for whales,” Pershing said. “We need to make sure that when we're doing these things that it’s based on really sound, quantifiable science.”
Still, the paper notes that restoring whale populations could be a “low-regret” climate strategy that’s less risky and longer lasting than proposed geoengineering solutions, such removing CO2 from the atmosphere and injecting it into the seabed.
“Due to the severity, and escalating nature of the climate crisis, we need to do everything we can,” Pearson said. “Even if whales end up playing a relatively small role in the global carbon budget, it's going to help.”
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