Estimated value: $2 million.

How much is an ecosystem worth?

If you care about stopping climate change, it’s time to get out your wallet, head to the beach, find the nearest whale, and cut her a check for $2 million. It’s the least you could do.

Whales do a lot of unpaid work cleaning up our carbon mess. They accumulate tons of it in their enormous bodies as they grow (the equivalent of a thousand trees or more), and take it to the bottom of the ocean when they die, effectively removing it from circulation in the atmosphere. And scientists have found that whale poop is a feast for phytoplankton near the ocean surface, which suck multiple forests’-worth of CO2 from the air and sequester it in the deep.

In December, a group of economists at the International Monetary Fund calculated that the value of this service, based on the current market price of CO2 (plus other industries whales support, like tourism and fisheries), is about $2 million per whale over the course of its life. Add up the world’s current population of whales, and that’s more than $1 trillion.

This kind of multidisciplinary science—translating the services that species and ecosystems (marshes, coral reefs, forests, etc.) provide into dollars, pounds of carbon, and other hard numbers—is known as “natural capital economics.” It’s not just carbon: Natural capital economists also measure the value of other “ecosystem services” like food production, water storage, pollination, removal of toxins from the air, soil, and water, and even protection against erosion and floods.

Read the full story here.