Tackling degraded oceans could mitigate climate crisis - report

(The Guardian, 4 Dec 2019) Greenpeace says efforts to restore seas’ ecosystems would boost their capacity to absorb heat and store carbon.

Halting overfishing and the plastic pollution of the oceans could help tackle the climate emergency by improving the degraded state of the world’s biggest carbon sink, a report has found.

The oceans absorb both the excess heat generated by our greenhouse gas emissions, and absorb carbon dioxide itself, helping to reduce the impacts of climate chaos. But we are rapidly reaching the limits of the oceans’ absorptive capacity as our pillage of marine life is disrupting vital ecosystems and the natural carbon cycle.

Creating ocean sanctuaries and forging a new treaty to protect the oceans, with a target of safeguarding at least 30% of the oceans by 2030, could restore many areas to health and combat global heating, according to the report entitled Hot Water: the climate crisis and the urgent need for ocean protection, published by Greenpeace International on Wednesday.

Phytoplankton such as algae, for instance, transform dissolved carbon dioxide into organic carbon, which then forms part of the food chain. Gradually some of this sinks to the sea bottom where it is buried in sediment. Without the biological carbon pump that this entails concentrations of carbon in the atmosphere today would be about 50% higher, according to estimates cited in the report.

Krill – small crustaceans – also form a vital part of the carbon cycle in the seas as they move through levels of the ocean, and play a big role in the diet of larger species. But krill populations have been in long-term decline since the 1970s due to pollution, overfishing and climate change.

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The Guardian, 4 Dec 2019: Tackling degraded oceans could mitigate climate crisis - report