The Invisible Engine
Every day, trillions of microscopic organisms in the ocean surface waters absorb carbon dioxide through photosynthesis. When they die, their carbon-rich remains sink into the deep ocean, where the carbon stays locked away for centuries. This is the biological carbon pump — and it moves more carbon annually than all human emissions combined.
How It Works
Phytoplankton absorb CO2 at the surface. Zooplankton eat them and produce carbon-rich fecal pellets that sink rapidly. Dead organisms aggregate into marine snow — a constant drizzle of organic matter to the deep. About 30% reaches below 1000 meters, where it stays for 500-1000 years.
The Threat
Ocean warming disrupts this pump. Warmer surface water stratifies more strongly, reducing mixing that brings nutrients from the deep. Less nutrients means less phytoplankton, which means less carbon pumped. It is a dangerous feedback loop.