A great video by
on how the relationship between great whales and the trophic cascade- whale activity supports sea life and naturally sequesters carbon dioxide, limiting climate change.
An article by Sandy Dechert additionally discusses how increasing whale populations can combat the effects of climate change:
The great whales have a meal plan that actually sustains their diet. They feed in deep, dark waters. When great whales surface, they expel in their iron- and nitrogen-rich feces nutrients that are scarce at the uppermost water levels. In the photic zone at the surface, the increased light causes photosynthesis, and the whale poop fertilizes the plant plankton that live up there. When the huge mammals leap and dive, their activity kicks the plankton around in the photic zone, giving it more time to reproduce. Plant plankton feeds animal plankton, which sustains larger creatures like fish and krill—the original diet of the whales!
Key to the climate effects: this plant plankton also absorb carbon dioxide, a potent greenhouse gas, from the atmosphere in large quantities. When the plankton eventually sink, they take the carbon dioxide down too, naturally sequestering it just as land vegetation does.
The science tells us that the huge whale population before the 1800′s may have been removed tens of millions of tons of carbon from the atmosphere every year. As the video states, “The more whales there are, the more plankton there is. The more plankton there is, the more carbon is drawn out of the air.”