Humanity is exacting a terrible toll on the ocean. The Intergovernmental Panel on Climate Change (IPCC) will publish its Special Report on the Ocean and Cryosphere in a Changing Climate later this week. Its overarching message will be that global warming, combined with the negative impacts of numerous other human activities, is devastating our ocean, with alarming declines in fish stocks, the death of our reefs, and sea level rise that could displace hundreds of millions of people.