The theme for the 2018 Global Change Institute photo competition is ‘Coral Reefs under Global Change’. Oceans cover more than 70% of the Earth’s surface and play a crucial role in determining weather, stabilising planetary temperature and regulating the atmosphere. Life would not be possible without our oceans. Coral reefs make up 0.1% of the Earth’s surface, and yet they are known to house as much as 25% of all marine biodiversity. Research shows that at the current rate of warming, coral reefs – which provide food, jobs and storm protection to several hundred million people – will disappear completely by 2050. More than simply warming marine waters, climate change is also inducing increased ocean acidity that will take generations to negate. In this the International Year of the Reef, rising sea levels, unsustainable fishing, global pollution and coastal development are all threatening the future of our coral reefs, and the resources they provide.