Ocean warming is happening faster as the ocean absorbs most of the increase in the heating of the atmosphere from climate change. This can harm marine animals such as corals through a process known as coral bleaching. It also forces some fishes and other animals to find cooler waters.

Sea ice loss happens as warmer ocean temperatures cause sea ice in the Arctic and Antarctic to melt faster. Less sea ice means species such as the polar bear are losing their habitat.

Sea level rise is caused by the ocean expanding as it heats, and more land ice (in glaciers and ice sheets) melting and flowing into the ocean. If all the ice sheets in the Arctic and Antarctic were to melt, sea levels would rise by over 65 metres.

Storms are becoming more powerful and are happening more often as the ocean and air temperatures increase. These can damage coastal habitats, communities, and cities.

Ocean acidification is the name given to a chemical change in the ocean. This takes place when increased carbon dioxide in the atmosphere is absorbed by the ocean. This leads to an increase in acidity which can affect animals with chalky shells or structures.

Direct human impacts happen as well as changes to the environment. By 2050, sea level rise will mean annual coastal floods will affect land that is now home to 300 million people. Changes in the ocean are also affecting fisheries around the world.