1.5-minute read

In nature we never see anything isolated,
but everything in connection with something else
which is before it, beside it, under it and over it.

Johann Wolfgang von Goethe

Sometimes, solutions to our most complex problems come from unexpected places. Could the restoration of great whale populations help us to combat climate change?

If left to its own devices, nature has a tremendous capacity to heal itself and protect us from the harmful impacts of a rapidly warming world. When we maintain greenhouse gas emissions at people- and planet-friendly levels, Earth systems can absorb enough GHG’s to keep global heating in check. Currently, about 25% of the CO₂ emissions that contribute to global heating are absorbed by oceans. Most of the carbon dioxide in oceans is consumed by microscopic algae called phytoplankton. Like trees, the tiny green plants utilize CO₂ for growth. Globally, phytoplankton absorb as much carbon dioxide from the atmosphere as tropical rainforests. Similar to the effects of deforestation, a reduction in phytoplankton can lead to more GHG emissions in the atmosphere and more heating. That’s where whales come in, or more specifically, the poop of whales.

According to scientists at the University of Tasmania, great whales have a big role to play in helping to cool the planet by dispensing the iron that carbon-absorbing phytoplankton need to grow. Adult whales in the Southern Ocean can eat two tons of iron-rich krill a day—that’s about 40 million mini-crustaceans. Because what goes in must come out, the krill consumed by whales converts to a whole lot of iron-infused phytoplankton fertilizer. By recycling an essential nutrient at a concentration ten million times higher than occurs in seawater, whales contribute to the continued functioning of one of Earth’s most important carbon sinks. The Tasmanian researchers estimate that a 12,000-strong population of iron-excreting sperm whales could stimulate the growth of enough phytoplankton to remove 200,000 tons of carbon annually—the CO₂ equivalent of 17,000 cars traveling 9,320 miles a year.

Marine biologists believe that tens of millions of whales were removed from oceans in the thousand years of active whaling prior to the international moratorium in 1982; this estimated 90% decline in the planet’s largest inhabitants has likely altered the functioning of marine ecosystems. As if we need another good reason to keep on saving the whales other than their all-around awesomeness, protecting and restoring populations of the colossal animals will help maintain healthy oceans that continue to absorb GHG emissions and reduce global heating. A win for the super-poopers is a win for people and the planet.