The ocean takes up heat and carbon, reducing the adverse effects of climate change. The ocean plays a central role in regulating our climate and weather. The ocean has taken up more than 90% of the extra heat energy stored on the planet arising from increased greenhouse gases and is taking up around 25% of the extra carbon emitted by human activities1. The ocean also receives all the water from melting ice. Without such ocean uptake and storage of heat and carbon from the atmosphere, there would be much greater increases in air temperature and atmospheric CO2 .