Marine ecosystems around the UK can both increase and decrease atmospheric carbon dioxide levels. Carbon loss and gain globally by these ecosystems has the potential to influence climate change.

Blue carbon has the potential to contribute to the UK’s carbon sequestration efforts. However, damage to blue carbon habitats may also result in release of carbon, potentially contributing to climate change. Blue carbon policy seeks to maximise the sequestration and storage of carbon within habitats.

Investment in, and protection of, blue carbon systems is not as developed as in woodlands and peatlands and most are not currently included in the UK’s national GHG inventory. This is in part the result of scientific uncertainties about the carbon benefits of blue carbon habitats, as well as uncertainties about the extent of those habitats in UK waters. However, understanding of the carbon sequestration and storage in blue carbon habitats is increasing, and plans and legislation are evolving to reflect this. The UK’s new regional Marine Plans include considerations of the blue carbon value of their waters, and the UK Government is considering blue carbon value in the designation of pilot sites for a new category of highly protected marine areas. Private investment is currently constrained by lack of a UK carbon code for blue carbon habitats, but the UK Government has funded the development of such a scheme for saltmarshes.

In addition to carbon sequestration and storage, blue carbon habitats provide a range of co-benefits of value. These include improved water quality, flood protection, protection from coastal erosion, increased fish and shellfish abundance, and increased biodiversity.

https://post.parliament.uk/research-briefings/post-pn-0651/