But the ocean absorbs a much larger portion of sunlight than the average land. Hence more energy absorbed if there's more ocean. And that leads to more heating.

But the ocean absorbs a much larger portion of sunlight than the average land. Hence more energy absorbed if there's more ocean. And that leads to more heating. Maybe something like boreal forests work best. But large carbon sinks like from the carboniferous era (coal and oil deposits) can't happen anymore anyway since fungi have evolved to break down wood.