Sea levels could rise by up to 1.1 metres by 2100 if greenhouse-gas emissions continue to rise.
Credit: Ian Forsyth/Getty

The world’s oceans have long helped to stave off climate change by absorbing heat and carbon dioxide from the atmosphere. But that is changing, with devastating consequences for humanity in the coming decades, leading researchers warn in a high-level report commissioned by the United Nations.

The rate at which oceans are warming has doubled since the early 1990s, and marine heat waves are becoming more frequent and intense ― trends that are reshaping ocean ecosystems and fuelling more powerful storms. And as the oceans absorb CO2, they are becoming more acidic, which threatens the survival of coral reefs and fisheries.

The special report on oceans and ice by the Intergovernmental Panel on Climate Change (IPCC) warns that without steep cuts to greenhouse-gas emissions, fisheries will falter, the average strength of hurricanes will increase and rising seas will increase the risk of flooding in low-lying areas around the globe.