The oceans also regulate the global climate; they mediate temperature and drive the weather, determining rainfall, droughts, and floods. They are also the world’s largest store of carbon, where an estimated 83% of the global carbon cycle is circulated through marine waters.

But the interaction between these two natural forces is altering, and the exchange is intensifying. We’re seeing the consequences of this around the world. In the last 200 years, the oceans have absorbed a third of the CO2 produced by human activities and 90% of the extra heat trapped by the rising concentration of greenhouse gases.