What is the primary thermal consequence for surfaces that have a very low albedo, such as the open ocean?

Answer

They retain most solar energy and heat up significantly.

Surfaces with low albedo, like dark water, absorb light well. This retained energy leads to significant heating, as evidenced by the open ocean reflecting only about 3% of radiation.

What is the primary thermal consequence for surfaces that have a very low albedo, such as the open ocean?
Earthsurfacereflectivity