evidence: The ocean generates 50 percent of the oxygen we need, absorbs 25 percent of all carbon dioxide emissions and captures 90 percent of the excess heat generated by these emissions. It is not just ‘the lungs of the planet’ but also its largest ‘carbon sink’ – a vital buffer against the impacts of climate change. The ocean is central to reducing global greenhouse gas emissions and stabilizing the Earth’s climate. However, increasing greenhouse gas emissions have affected the health of the ocean – warming and acidifying seawater – causing detrimental changes to life under water and on land, and reducing the ocean’s ability to absorb carbon dioxide and safeguard life on the planet.