Seeing a whale stranded on a beach often provokes a strong reaction. It can make people curious – beached whales can do strange things, like explode. It can also be upsetting to witness a creature so magnificent in water reduced to lifeless blubber on land. What rarely registers, however, is the lost opportunity for carbon sequestration.

Whales, particularly baleen and sperm whales, are among the largest creatures on Earth. Their bodies are enormous stores of carbon, and their presence in the ocean shapes the ecosystems around them. 

From the depths of the ocean, these creatures are also helping to determine the temperature of the planet – and it's something that we've only recently started to appreciate.

When whales die, they sink to the ocean floor – and all the carbon that is stored in their enormous bodies is transferred from surface waters to the deep sea, where it remains for centuries or more.

In the 2010 study, scientists found that before industrial whaling, populations of whales (excluding sperm whales) would have sunk between 190,000 to 1.9 million tonnes of carbon per year to the bottom of the ocean – that's the equivalent of taking between 40,000 and 410,000 cars off the road each year. But when the carcass is prevented from sinking to the seabed – instead, the whale is killed and processed – that carbon is released into the atmosphere.

A recent IMF study states that whale protection must now become a top priority in the global effort to tackle climate change.

Source: BBC Future Planet

Image: BBC Future Planet