Restoring global whale populations has the equivalent impact as planting 100bn trees. What they eat turns to poop. The poop creates a phytoplankton bloom that feeds into the ocean ecosystem. A small proportion of this biomass ends up on the ocean floor. And that Carbon is locked away forever.
This cycle is known as the carbon pump .. and it restores ocean health… and that is a significant weapon in our armoury when fighting the climate crisis.