The first success of the environmental movements of the 1960s was to save the whale. Now, with deep irony, whales may be about to save us with their poo. A new scientific report from the University of Vermont, which gathers together several decades of research, shows that the great whales which nearly became extinct in the 20th century – and are now recovering in number due to the 1983 ban on whaling – may be the enablers of massive carbon sinks via their prodigious production of faeces.

Not only do the nutrients in whale poo feed other organisms, from phytoplankton upwards – and thereby absorb the carbon we humans are pumping into the atmosphere – even in death the sinking bodies of these massive animals create new resources on the sea bed, where entire species exist solely to graze on rotting whale. There’s an additional and direct benefit for humans, too. Contrary to the suspicions of fishermen that whales take their catch, cetacean recovery could “lead to higher rates of productivity in locations where whales aggregate to feed and give birth”. Their fertilizing faeces here, too, would encourage phytoplankton which in turn would encourage healthier fisheries.

Such propositions speak to our own species’ arrogance. As demonstrated in the fantastical geoengineering projects dreamed up to address climate change, the human race’s belief that the world revolves around it knows no bounds. What if whales were nature’s ultimate geoengineers? The new report only underlines what has been suspected for some time: that cetaceans, both living and dead, are ecosystems in their own right. But it also raises a hitherto unexplored prospect, that climate change may have been accelerated by the terrible whale culls of the 20th century, which removed hundreds of thousands of these ultimate facilitators of CO2 absorption. As Greg Gatenby, the acclaimed Canadian writer on whales told me in response to the Vermont report, “about 300,000 blue whales were taken in the 20th century. If you average each whale at 100 tons, that makes for the removal from the ocean of approximately 30m tons of biomass. And that’s just for one species”.

A defecating sperm whale off the coast of Sri Lanka. Photograph: Andrew Sutton There’s another irony here, too. American whaling, as celebrated in Herman Melville’s Moby-Dick (1851), declined in part because of the discovery of mineral oil wells in the second half of the 19th century. One unsustainable resource – the whale oil which lit and lubricated the industrial revolution – was replaced by another. By killing so many whales, then turning to carbon-emitting mineral oil, humans created a double-whammy for climate change. (Conversely, and perhaps perversely, some US commentators have claimed that capitalism saved the whales rather than environmentalists. They contend that our use of mineral oil actually alleviated the pressure on whale populations – proof, they say, that human ingenuity has the ultimate power to solve the planet’s problems).

The 10 scientists who jointly contributed to the new paper note the benefits of “an ocean repopulated by the great whales”. Working on a whalewatching boat off Cape Cod last month, I witnessed astonishing numbers of fin whales, humpbacks and minkes feeding on vast schools of sand eels. I watched dozens of whales at a time, co-operatively hoovering up the bait – and producing plentiful clouds of poo in the process. (Having been at the receiving end of a defecating sperm whale, I can testify to its richly odiferous qualities.)

Observers in the Azores have reported similarly remarkable concentrations of cetaceans this summer. And with a 10% increase in humpback calves returning to Australian waters each year, and blue whales being seen in the Irish Sea, a burgeoning global population of cetaceans might not just be good for the whalewatching industry, they may play a significant role in the planet’s rearguard action against climate change.

It would certainly be a generous return on their part, given what we’ve inflicted on them. Indeed, as Melville imagined in his prophetic chapter in Moby-Dick, Does the Whale’s Magnitude Diminish?, the whale might yet have the last laugh, regaining its reign in a flooded world of the future to “spout his frothed defiance to the skies”.