The International Programme on the State of the Ocean (IPSO) was established to improve our understanding of the role of the ocean at an Earth System Level and its contribution to enabling life to exist on Earth. Every sea and ocean on our planet is part of one, global Ocean. This Ocean is like the earth's circulatory system: it performs numerous vital functions which make the planet habitable and we cannot survive without it. Currently, the Ocean is in a critical state of health. If it continues to decline, it will reach a point where it can no longer function effectively and our planet will be unable to sustain the ecosystems that support humankind. Climate change is the biggest single threat to our Ocean's health, but it's not the only one. If the Ocean is to continue functioning at a level capable of sustaining life as we know it, we need to tackle climate change and alleviate the other pressures we exert upon it.