The ocean plays a vital role in regulating planetary health. It keeps temperatures down by absorbing heat and mitigates the effect of greenhouse gas emissions by soaking up carbon dioxide. But this comes at a cost. As ocean temperatures increase, we are seeing a rise in ocean acidification and a drop in oxygen levels, both of which are having a dramatic impact on many of the organisms that live in the sea. Rising sea levels caused by the melting ice-caps are threatening to inundate islands across the South Pacific and beyond. It is an alarming situation.

But it is not too late to restore ocean health. Alongside global efforts to reduce emissions, lower temperatures and eliminate plastic waste, local initiatives like Marine Protected Areas can encourage biodiversity through sustainable fisheries, and can rapidly restore the ocean's health - and help us tackle the climate and biodiversity crisis.

David Booth is Professor of Marine Ecology and Director of the Centre for Environmental Sustainability at the University of Technology in Sydney, Australia.

For more information, visit https://www.professordavidbooth.com