Seeing the wood for the trees - Is reforesting theScottish Highlands a good way to sequesteratmospheric carbon dioxide?

This PhD project concerns one of the most pressing issues of our time; the 'Climate Emergency', and the proposed use of tree planting to mitigate climate change.

Planting trees for carbon dioxide (CO2) sequestration is a mitigation strategy for climate change that is rapidly gaining momentum in national and international policy contexts (UNEP 2011; New York Declaration on Forests 2014). Recent high profile publications (e.g.

Bastin et al. 2019; Lewis et al. 2019) have emphasized the benefits of afforestation, but have attracted serious criticism for oversimplifying the underpinning science, exaggerating the carbon (C) sequestration potential and failing to acknowledge the possible adverse consequences of tree planting in a range of contrasting environmental, ecological and social contexts (see commentson Bastin et al. 2019).Scotland is currently a relatively sparsely wooded country (~17% of the land area),but could support a much greater woodland coverage, as it has in the past.

The Scottish Government has therefore defined annual targets to increase woodland cover - with an assumed parallel increase in C storage - and hence contribute to climate change mitigation.