15% of modern global warming (ocean) can be attributed to geothermal heat fluxes through the sea floor that persistently heat the ocean.

Evidence of more than 100,000 formerly or currently active volcanic vents permeate the Earth’s sea floor (Kelley, 2017).

Active volcanoes spew 380°C sulfuric acid and “metal-laden acidic fluids” into the bottom waters of the world ocean on a daily basis. Literal ocean acidification is thus a natural phenomenon.

The carbon dioxide concentrations present in these acidic floods reach “astounding” levels, dwarfing the potential for us to even begin to appreciate the impact this explosive geothermal activity has on the Earth’s carbon cycle.

Image Source: Kelley, 2017

Geothermal heating warms up the last 2000 m of the global ocean “by about 0.3°C to 0.5°C” (Emile-Gaey and Madec, 2009). The heat fluxes are systemically positive, span “the entire seafloor,” and the circulation is largely horizontal at…