Why Whales Matter More to the Climate Than You Might Think

For decades, the climate conversation has focused on forests, wetlands, soils and renewable energy. The ocean is increasingly recognized as another critical part of the climate system, but one of its most extraordinary climate actors is often overlooked: whales.

Whales do not stop climate change by themselves. They cannot replace emissions reductions, renewable energy or ecosystem restoration. But these enormous marine mammals participate in processes that influence ocean productivity, nutrient cycling and the movement of carbon through marine ecosystems.

That makes protecting whales about more than protecting charismatic animals. It is also about maintaining the ecological machinery of a healthy ocean.

The Ocean Is Already a Major Climate Regulator

The ocean absorbs roughly 31 percent of human carbon dioxide emissions, helping prevent even more carbon dioxide from remaining in the atmosphere. Much of this carbon movement involves microscopic organisms, particularly phytoplankton, which use carbon dioxide during photosynthesis.

Phytoplankton may be tiny, but their collective influence is enormous. They form the foundation of marine food webs and participate in the biological carbon pump, a system through which carbon captured near the ocean surface can eventually move into deeper waters.

This is where whales enter the story.

Whales Help Move Nutrients Through the Ocean

Imagine the ocean as a vast biological factory.

For that factory to keep operating, it needs raw materials. Nitrogen, phosphorus and iron are among the nutrients that can limit biological productivity in surface waters.

Whales can help redistribute some of these nutrients.

Many whale species feed at depth or in nutrient-rich areas before returning to the surface to breathe. Their waste releases nutrients back into surface waters. Scientists have described this process as the "whale pump."

Those nutrients can stimulate phytoplankton and other organisms, particularly in areas where nutrients are scarce.

The effect is not identical everywhere. Ocean chemistry, whale species, feeding behaviour, prey availability and local environmental conditions all matter.

That distinction is important because the popular version of the whale-carbon story can sometimes make the science sound much more certain than it actually is.

New Research Is Showing Where the Effect Matters Most

A 2025 study published in Proceedings of the National Academy of Sciences examined how baleen whales contribute nutrients to high-latitude feeding grounds, including the Nordic and Barents seas.

The researchers found that whale-derived nutrients can increase marine primary production. The annual effect was modest in most areas, generally below 2 percent, but under certain summer conditions and in offshore areas where other nutrient sources were limited, the effect reached as much as 10 percent.

That finding is significant because it demonstrates something more nuanced than "whales capture huge amounts of carbon."

Whales can influence the productivity of ecosystems around them.

And productive ecosystems can influence how carbon moves through the ocean.

Some Whales Can Also Transport Iron

The story becomes particularly interesting in regions where iron limits phytoplankton growth.

Sperm whales, for example, dive into deeper waters to feed and subsequently return to the surface. Research in the Southern Ocean has found that their iron-rich waste can stimulate new primary production.

One study estimated that Southern Ocean sperm whales could stimulate approximately 400,000 tonnes of carbon export to the deep ocean annually, while the whales themselves would respire approximately 200,000 tonnes of carbon.

But these numbers should not be interpreted as a universal global estimate for all whales.

The effect depends heavily on local ocean conditions. A whale population swimming through an iron-poor environment may have a very different influence from one living in waters where nutrients are already abundant.

This is one reason scientists continue to investigate the whale pump rather than treating it as a settled climate solution.

Dead Whales Can Carry Carbon Into the Deep Ocean

There is another mechanism that is easier to understand.

Whales are enormous animals, and their bodies contain substantial quantities of carbon accumulated during their lifetimes.

When a whale dies naturally and its carcass sinks into the deep ocean, some of that carbon can become part of deep-sea ecosystems and sediments. These events are known as whale falls.

A whale fall can create an entire ecological community. Fish, crustaceans, worms, bacteria and other organisms can feed on the carcass, while the surrounding ecosystem benefits from the nutrients released during decomposition.

Some of the carbon can remain associated with deep-sea sediments for very long periods. NOAA notes that carbon associated with whale falls can potentially remain sequestered for hundreds to thousands of years.

This makes the death of a whale part of a much larger ecological cycle.

The whale does not simply disappear.

Its body becomes infrastructure for an ecosystem that exists largely beyond human view.

The Historical Loss of Whales Changed More Than Whale Populations

Industrial whaling dramatically reduced populations of many large whale species.

That loss was obviously devastating for biodiversity. But it also removed millions of tonnes of living biomass and altered ecological relationships across marine environments.

Research published in Global Change Biology examined historical and projected carbon sequestration associated with five baleen whale species in the Southern Hemisphere.

The study estimated that these whale populations could have sequestered around 400,000 tonnes of carbon per year at pre-exploitation abundance. Following the collapse of whale populations from commercial exploitation, the estimated carbon sequestration associated with whale falls fell substantially.

This does not mean commercial whaling caused today's climate crisis. That would be an enormous overstatement.

It means that removing large numbers of whales also altered a biological component of the ocean carbon cycle.

But Are Whales Actually a Climate Solution?

Here is where the conversation needs some intellectual honesty.

Whales are important to ocean ecosystems.

But they are not a substitute for cutting greenhouse gas emissions.

A 2025 scientific review examining fish, whales and other marine mammals concluded that the contribution of great whales to ocean carbon export is relatively small compared with the total marine biological carbon cycle. It also emphasized major uncertainties surrounding the whale pump, including how much whale-derived nutrients ultimately result in long-term carbon sequestration.

A 2026 review of the ocean carbon cycle went even further in challenging exaggerated claims about marine organisms and carbon sequestration. It emphasized that the ocean's enormous carbon sink is fundamentally governed by physical and chemical processes, and cautioned against presenting whales as a major climate-mitigation mechanism.

That is an important corrective.

There is a difference between saying:

"Whales influence the carbon cycle."

and saying:

"Whales can solve climate change."

The first is scientifically defensible.

The second is not.

The Strongest Argument for Protecting Whales Is Bigger Than Carbon

Perhaps the most important lesson is that we do not need to exaggerate whale carbon sequestration to justify whale conservation.

Whales influence food webs.

They redistribute nutrients.

They support marine productivity.

Their carcasses create deep-sea ecosystems.

They participate in ocean carbon processes.

And their populations remain vulnerable to human pressures including fishing-gear entanglement, vessel strikes, underwater noise, pollution and climate-driven changes in marine ecosystems.

Protecting whales therefore delivers multiple ecological benefits at once.

The climate connection is an additional reason to care, not the only reason.

What This Means for Climate Policy

The whale story points toward a broader principle in environmental policy: healthy ecosystems are networks, not isolated carbon-storage machines.

A forest is not simply a pile of trees storing carbon.

A mangrove is not simply a carbon credit.

A wetland is not simply a climate asset.

And a whale is not simply a swimming carbon sink.

These systems work because countless biological relationships operate simultaneously.

For whales, conserving populations can help maintain those relationships. Measures such as reducing ship strikes, improving fishing-gear management, protecting important feeding and breeding grounds and reducing ocean pollution can therefore have biodiversity and ecosystem benefits alongside their potential climate benefits.

But governments and businesses should resist turning every conservation intervention into a carbon-credit opportunity.

The scientific evidence is not yet strong enough to treat whale restoration as a straightforward, independently verifiable carbon-removal technology.

The Bigger Picture

The most fascinating thing about whales may not be how much carbon their bodies contain.

It may be how much they reveal about the interconnectedness of the ocean.

A whale dives.

It feeds.

It returns to the surface.

It releases nutrients.

Phytoplankton respond.

Other organisms feed on them.

Carbon moves through the food web.

Eventually, some carbon can move deeper into the ocean.

The process is neither simple nor perfectly understood. But it demonstrates something climate policy sometimes forgets: nature's climate systems are living networks.

We should protect whales because they are extraordinary species with intrinsic ecological value.

We should protect them because healthy whale populations contribute to functioning marine ecosystems.

And yes, we should recognize that they participate in the ocean's carbon cycle.

But we should not turn them into a climate miracle.

The real lesson is more powerful.

When we protect the systems that keep the ocean alive, we also protect some of the natural processes that help regulate our climate.

That is why whales matter more to the climate than you might think.

And perhaps even more importantly, it is why the health of the ocean cannot be separated from the health of the planet.