 Coral reefs provide food and habitat for a wide range of organisms and ecological goods and services. Warm water coral reefs occupy shallow sunlit waters to grow and calcify at high rates, while mesophotic coral reefs accumulate calcium carbonate at lower rates in deeper locations. Cold water coral reefs are found in the dark depths. Coral reefs face significant challenges from human activities including pollution, over-harvesting, physical destruction, and climate change. Even with lower greenhouse gas emission scenarios, warm water coral reefs may be eliminated by 2040 to 2050 due to rapid ocean warming and acidification. Cold water corals are also threatened by these factors. Evidence that coral reefs can adapt at sufficient rates to keep up with these changes is minimal, and observations of tropical species appearing at high latitudes do not necessarily mean entire coral reef ecosystems are shifting. Coral reefs are likely to degrade rapidly over the next 20 years, presenting challenges for the 500 million people who depend on them for food, income, coastal protection, and other services. Rapid advances towards the goals of the Paris Climate Agreement are necessary to prevent increasing poverty, social disruption, and regional insecurity. This article was authored by Ove Hegg Goldberg, Ove Hegg Goldberg, Ove Hegg Goldberg and others. We are article.tv, links in the description below.