Climate change: Whales "worth a thousand trees" not the whole story
In case we needed another reason to save the whales, a compelling one has come along courtesy of the International Monetary Fund (IMF). As far as fighting climate change is concerned, "one whale is worth thousands of trees," the organization has said. It calls for restoring whales to pre-whaling populations of 4 or 5 million, up from about 1.3 million now. But reports suggesting that trees are somehow worse or less important than whales in the fight against climate change are missing the point.
"The carbon capture potential of whales is truly startling," an IMF statement says, citing that great whale species take an average of 33 US tons (30 metric tons) of carbon dioxide out of the atmosphere, and for hundreds of years thanks to their slow rate of decay at the bottom of the ocean. Great whales include species regulated by the International Whaling Commission, including blue, gray, minke, right and sperm whales.
"A tree, meanwhile, absorbs only up to 48 pounds of [carbon dioxide] a year," the statement continues, though in fairness to trees, that still equates to more than a couple of tons for a 100-year old tree, which may have the good fortune of still being alive after that time.
Further, whales also encourage the growth of phytoplankton which is thought to have captured around 41 billion US tons (37 metric tons) of carbon dioxide. According to IMF calculations that's the equivalent of four Amazon rainforests.
Though some whales feed on phytoplankton, whales in general encourage phytoplankton growth. Their waste contains iron and nitrogen which phytoplankton need, while their movement through the water brings minerals up to and across the ocean surface. Increasing phytoplankton productivity by 1 percent would capture extra hundreds of millions of tons of carbon dioxide, or "equivalent to the sudden appearance of 2 billion mature trees."
The IMF argues that protecting whales has significant scope to contribute to carbon capture because great whale numbers are massively depleted after more than a century of whaling. Blue whale numbers fell by over 99 percent during the 20th century. Though numbers have recovered somewhat, the global population is still only 3 percent of what it was before the rise of whaling.
The organization argues that whales could provide a simple, economically-viable alternative to ambitious, untested carbon capture proposals which would seek to take carbon from carbon dioxide in the atmosphere to bury in the ground. It argues that the economic value of a great whale is more than US$2 million, based on an individual's contribution to carbon capture and its lifetime contribution to economic activity such as fishing and ecotourism.
But be wary of coverage suggesting that environmental activists would be better off saving whales than planting or saving trees. Though one whale may make a much bigger contribution than any one tree, there are orders of magnitude more trees than whales in the world. Not to mention that it's easier for an activist to plant a tree than it is to save a whale. Clearly, it's not an either-or scenario. From an environmental perspective, it'd be beneficial to have more trees and whales, not to mention more biodiversity, biomass and sequestered carbon in general, though admittedly, that doesn't make for as eye-catching a headline.
The IMF even cites the example of the United Nations Collaborative Programme on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (REDD) as a model to emulate with whale protection. The REDD program gives incentives to countries which preserve their forests in an effort to retain captured carbon dioxide.
The IMF suggests that similar incentives could be offered to, say, shipping companies which avoided whale populations. It'd be most peculiar for the IMF to cite forest conservation as a shining example, and then call for those efforts to be suspended in favor of whales. Fortunately, that's not what it's suggesting.
But more can certainly be done to help whales. As the IMF points out, whaling is no longer the only threat posed by humankind, with fishing nets, plastic waste, noise pollution, ship strikes and the warming oceans themselves posing problems to whale populations. At the current rate, it will take 30 years for current whale populations to double, and generations more for their populations to be restored. "Society and our own survival can’t afford to wait this long," the IMF concludes.
The IMF doesn't claim that whales trump trees in efforts to combat climate change. It claims that whales represent an enormous opportunity – literally and figuratively – to do more and has used trees as an illustrative yardstick to make that point. "Nature has had millions of years to perfect her whale-based carbon sink technology," the IMF says. "All we need to do is let the whales live."
Source: International Monetary Fund