A ''Blue Carbon'' fund able to invest in the maintenance and rehabilitation of key marine ecosystems should be considered by governments keen to combat climate change. A new Rapid Response Report estimates that carbon emissions (equal to half the annual emissions of the global transport sector) are being captured and stored by marine ecosystems such as mangroves, salt marshes and seagrasses.

A combination of reducing deforestation on land, allied to restoring the coverage and health of these marine ecosystems could deliver up to 25% of the emissions reductions needed to avoid ‘dangerous' climate change.

But the report, produced by three United Nations agencies and leading scientists and launched during National Marine Month in South Africa, warns that far from maintaining and enhancing these natural carbon sinks humanity is damaging and degrading them at an accelerating rate.

It estimates that up to 7% of these ‘blue carbon sinks' are being lost annually or seven times the rate of loss of 50 years ago.

"If more action is not taken to sustain these vital ecosystems, most may be lost within two decades," says the report Blue Carbon: the Role of Healthy Oceans in Binding Carbon launched by the UN Environment Programe (UNEP), the ÚN Food and Agricultural Organization (FAO) and the Intergovernmental Oceanographic Commission of UNESCO.