[hammock]

Summary:

The primary greenhouse gas is not CO2, its water vapour (>50% of all the atmospheric greenhouse gases)

Marine plants keep water vapor from getting out of hand.

Pollution that makes its way to the ocean, like toxic waste, oil and oil-based chemicals doesn't get "diluted" - it stays on the surface and emulsifies and can even be concentrated into microplastics.

The marine life then consumes these toxins, leading to their demise and death.

The decline of marine life leads to greater water vapor (greenhouse gas) in the atmosphere.