Whales worth about $1 trillion in carbon sequestration, analysis finds

A new analysis of whales suggests that each one is worth about $2 million in carbon sequestration -- and the global population is thus worth about $1 trillion.

How do whales sequester carbon? By eating stuff, getting big, then drifting to the bottom of the ocean after they die. This makes them carbon sinks on a scale even bigger than most trees, as the authors point out:

The carbon capture potential of whales is truly startling. Whales accumulate carbon in their bodies during their long lives. When they die, they sink to the bottom of the ocean; each great whale sequesters 33 tons of CO2 on average, taking that carbon out of the atmosphere for centuries. A tree, meanwhile, absorbs only up to 48 pounds of CO2 a year.

On top of that, the metabolic activity of whales -- their breathing, peeing and pooping -- stimulates huge growths of phyloplankton, which itself sequesters tons of carbon. As National Geographic notes, in a post about this new study ...

When phytoplankton die, much of their carbon gets recycled at the oceans surface. But some dead phytoplankton inevitably sink, sending more captured carbon to the bottom of the sea. Another study from 2010 found that the 12,000 sperm whales in the Southern Ocean draw 200,000 tons of carbon out of the atmosphere each year by stimulating phytoplankton growth and death through their iron-rich defecations.

When the study authors priced out the cost of carbon capture, that's how they arrived at the value of $2 million per whale. Read the rest