Apart from being extraordinary creatures, whales are also an incredible natural carbon sink. If they are allowed to return to pre-whaling numbers, scientists estimated that they could capture as much as 1.9 million tonnes of CO2 annually.
Humans have been hunting whales since prehistoric times. It wasn’t until the late 18th century though that whaling started to have a more serious impact on global whale populations. Due to the Industrial Revolution, demand for whale oil and meat increased and the advances in technology allowed people to exploit richer whaling grounds and kill more numbers.
The commercial hunting of whales in the 20th century is considered the greatest wildlife exploitation episode in human history. In 1982, after a long battle, the International Whaling Commission voted for a ban of commercial whaling that came into effect in 1986. Many species and populations have rebounded since then, however, many others did not recover.
According to research from the IMF, tens of millions of whales were killed during the thousand-year period of industrial whaling which decreased their population between 66% – 90%. Scientists have estimated that if industrial whaling didn’t happen, their populations (excluding sperm whales, which feed at greater depths) would have sunk up to 1.9 million tonnes of CO2 per year.
They provide carbon sequestration in several ways. They store large amounts of carbon in their bodies. When they die they take that carbon to the bottom of the ocean ensuring it stays in the deep sea rather than being released in surface waters.
Apart from being amazing paddleboard buddies, whales also provide another valuable climate benefit – their poo. Their iron-rich faeces stimulate the growth of phytoplankton – tiny marine algae which capture around 40% of all the CO2 produced in the world.
Whales are incredible animals and certainly deserve the science community and investors’ attention when it comes to their ability to tackle climate change. If whales are not being hunted for meat and oil, they could provide a massive amount of CO2 as a natural carbon sink and thus help countries in achieving their net zero emissions goals.
Correction: A previous version of this article stated that 1.9 billion tonnes of CO2 could be sunk and sequestered by whales. This has been corrected to “up to 1.9 million tonnes” in both the title and article.