The value of habitats of conservation importance to climate change mitigation in the UK

The twin pressures of climate change and biodiversity loss mean that it is imperative to manage land in ways that benefit carbon storage and biodiversity conservation. We focus on a set of UK habitats of recognised conservation value, first quantifying the carbon stored in the vegetation and top 30 cm of soil in these areas. We estimate that these areas store 0.55 gigatonnes of carbon in vegetation and soil to a depth of 30 cm, approximately 30% of the UK terrestrial carbon store to a similar depth, on 20% of the land area. Most of these high carbon, high conservation value habitats are in upland areas, with particularly notable extents and mass of carbon in Scotland. In their current condition, we estimate these areas to exert a net sequestration effect of more than 8 million tonnes of CO2 equivalents per year. Furthermore, restoration of these habitats from their current, generally poor condition could result in an extra 6-7 million tonnes of CO2 equivalents per year, in the context of the UK's total emissions of 455.9 million tonnes CO(2eq )in 2017. Restoration of degraded bogs would avoid significant annual emissions (currently negating significant sequestration by woodlands and coastal habitats) and should be a particular priority.