Over the past two decades, the pace of ocean warming has doubled. In addition to climate change, the poor state of oceans is exacerbated by acidification, eutrophication, increased plastic pollution and deep-sea mining. Coral reefs have probably already been lost, ocean currents may stall, and glaciers are melting faster than before. Ocean degradation directly threatens the livelihoods and food security of hundreds of millions of people, weakens the oceans’ ability to absorb carbon and accelerates biodiversity loss. Climate action, ocean protection and the reduction of nutrient runoff through improved soil health can influence the state of the oceans.