As aquatic plants and animals grow, and in particular as plankton grows, they absorb carbon, then bury it on the seafloor when they die. That’s the rationale behind iron fertilization, a geoengineering technique that some researchers think could counteract global warming.
From this perspective, whales aren’t just gardeners, but geoengineers as well. Marine biologist Trish Lavery of Australia’s Flinders University estimated that defecation by the Southern Ocean’s sperm whales ultimately sequesters some 400,000 tons of carbon dioxide every year. Prior to their commercial whaling decline, that population alone would have accounted for about roughly the amount emitted by one decent-sized coal-fired power plant.
(Factor in the amount of carbon sequestered in whale bodies as they grow, calculated University of Maine marine biologist Andrew Pershing, and you can think about whale conservation in terms of carbon credits.)
the bad news is that due to whaling, we no longer have 200 thousand whales, but only a couple of thousand left.