The Health of the Ocean
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 on Earth as we know it, we need to tackle climate change and alleviate the other pressures we exert upon it. For the health of the global Ocean is in a critical state.
This affects everyone, because — just like the climate — the Ocean forms one of the key operating systems of our planet. It creates more than half our oxygen, drives weather systems and modulates the atmosphere, as well as providing us with vital resources. So the Ocean functions at a fundamental 'Earth System' level, transcending national borders to help maintain life everywhere on Earth.
Damage to the Ocean is not as immediately apparent as terrestrial destruction, but it is just as serious. All of the stressors we have put on the Ocean — from over-fishing to various kinds of pollution — have contributed to its ill-health. Our fossil carbon dioxide emissions in particular are acidifying the Ocean, with enormous negative impacts on marine life and the functioning of key marine ecosystems such as coral reefs.
The Ocean has already absorbed more than 80% of the heat added to the climate system and around 33% of the carbon dioxide emitted by humans. Ecosystems are collapsing as species are pushed to extinction and natural habitats are destroyed. Scientists believe that there is still time to prevent irreversible, catastrophic changes to our marine ecosystems, but that this requires drastic action within a decade.
Further study: Int. Programme on the State of the Ocean