A Strategy to Protect Whales Can Limit Greenhouse Gases and Global Warming
by Ralph Chami, Thomas Cosimano and Connel Fullenkamp
“..a surprisingly simple and essentially “no-tech” strategy to capture more carbon from the atmosphere: increase global whale populations. Marine biologists have recently discovered that whales—especially the great whales—play a significant role in capturing carbon from the atmosphere (Roman and others 2014).
The carbon capture potential of whales is truly startling. Whales accumulate carbon in their bodies during their long lives. When they die, they sink to the bottom of the ocean; each great whale sequesters 33 tons of CO2 on average, taking that carbon out of the atmosphere for centuries. A tree, meanwhile, absorbs only up to 48 pounds of CO2 a year.
Wherever whales, the largest living things on earth, are found, so are populations of some of the smallest, phytoplankton. These microscopic creatures not only contribute at least 50 percent of all oxygen to our atmosphere, they do so by capturing about 37 billion metric tons of CO2, an estimated 40 percent of all CO2 produced. To put things in perspective, we calculate that this is equivalent to the amount of CO2 captured by 1.70 trillion trees—four Amazon forests’ worth—or 70 times the amount absorbed by all the trees in the US Redwood National and State Parks each year. More phytoplankton means more carbon capture.
If whales were allowed to return to their pre-whaling number of 4 to 5 million—from slightly more than 1.3 million today—it could add significantly to the amount of phytoplankton in the oceans and to the carbon they capture each year. At a minimum, even a 1 percent increase in phytoplankton productivity thanks to whale activity would capture hundreds of millions of tons of additional CO2 a year, equivalent to the sudden appearance of 2 billion mature trees. Imagine the impact over the average lifespan of a whale, more than 60 years.
Healthy whale populations imply healthy marine life including fish, seabirds, and an overall vibrant system that recycles nutrients between oceans and land, improving life in both places. The “earth-tech” strategy of supporting whales’ return to their previous abundance in the oceans would significantly benefit not only life in the oceans but also life on land, including our own.