The Ocean and Us

Blue Carbon

Soil organic carbon

Seagrasses

Living biomass

Salt Marsh

Estuarine Mangroves

Oceanic Mangroves

Tropical forest

0

500

1 000

1 500

2 000

2 500

eq/ha

tCO

2

Source: Murray and et al , Green Payments for Blue Carbon Economic Incentives for Protecting Threatened Coastal Habitats , 2011

Climate Change The oceans play a pivotal role in the regulation of climate change through the absorption and storage of heat, the uptake and sequestration of carbon dioxide from the atmosphere, the attenuation of storm surges, and the prevention of coastal erosion. Thus the oceans mitigate both the drivers and effects of climate change (SDG13 Take urgent action to combat climate change and its impacts ). The oceans absorb the vast majority of the heat trapped by atmospheric greenhouse gases (GHGs), that otherwise would have already warmed the atmosphere and fuelled the progression of climate change (GOC, 2014). Coastal ecosystems such as salt marshes, seagrass beds, and mangrove forests all contribute to the sequestration of carbon in marine sediments (i.e. ‘blue carbon’). Not only do these systems draw CO 2 out of the atmosphere, but they also trap carbon in detritus and sediment. Annual average carbon sequestration rates range from 4.4 ± 0.95 tonnes CO 2 -eq per hectare per year (for seagrass beds) to 8.0 ± 8.5 tonnes CO 2 -eq per hectare per year (for salt marshes) (Murray et al 2011). 22 0 500 1 000 tCO 2 eq/ha Seagrasses Salt Marsh Estuarine Mangroves Oceanic Mangroves Tropical forest

EUO © OCEANA Juan Cuetos

1 500

2 000

2 500

22 Estimated by converting grams of carbon sequestered to tonnes of CO 2 social cost of carbon (SCC) for the year 2015 as shown in table A1 from IAWG (2013).

-equivalent and using the

26 .