For most of the last century, whales were counted in barrels of oil. In 2019 a team of economists at the International Monetary Fund tried a different sum — and arrived at a startling number: a single great whale is worth more than $2 million, and the world's whales together, more than $1 trillion. Not for their meat. For the carbon they move.
The carbon in their bodies
A great whale builds carbon into its body across a long life — sixty years or more. When it dies, it sinks. Its carcass carries carbon down to the seafloor, where it stays locked away for centuries.
The pump
The larger effect happens while whales are alive. Feeding in the deep and releasing nutrient-rich waste near the surface — carrying iron and nitrogen across whole oceans as they migrate — whales fertilise phytoplankton, the microscopic drifting plants of the sunlit sea. This cycle is the whale pump.
Why phytoplankton matter
These invisible drifters do an outsized share of the planet's work: they produce at least half the oxygen we breathe and capture roughly 37 billion tonnes of CO₂ a year — about 40% of all produced. The IMF estimated that even a 1% rise in phytoplankton productivity from whale activity could capture hundreds of millions of tonnes of CO₂ — the equivalent of two billion mature trees appearing overnight.
What was lost, what could return
Before industrial whaling, the oceans held perhaps 4–5 million great whales. Today: around 1.3 million. Restoring them, the researchers estimate, could draw down 1.7 billion tonnes of CO₂ each year — the work of four Amazon rainforests — at a cost of about $13 per person, per year.
A note on the number
The $2 million figure is a model, not a measurement — an "if-then" estimate built on the carbon price plus the value whales add through fisheries and ecotourism. The authors call it conservative; others note the phytoplankton link is still being quantified.
The carbon in a sunken whale is real. The full price of a living one is still being learned.