Feasibility of woodland expansion for carbon offsetting in Scotland revisited

This paper develops an economic decision model to identify areas of economic opportunity for woodland expansion on land currently used for livestock farming in Scotland, assessing its potential contribution to achieving net-zero targets. Using high-resolution data, the model accounts for spatial variability in soil carbon stocks, timber yield classes, livestock stocking rates, and the projected impact of climate change on tree growth. The findings indicate that up to 19.6 % of Scottish land would be suitable for woodland expansion if strict environmental and financial criteria, aimed to demonstrate additionality in voluntary carbon markets, are applied. Woodland expansion could become an economically efficient land-use decision on 8.4 % to 16.4 % of Scottish land, for carbon prices ranging from £ 10 to £ 100 per CO₂ tonne. Over a 100-year average, this potential expansion could yield carbon offsets equivalent to 14 % to 23 % of Scotland's current greenhouse gas emissions. However, improving the quality of carbon offsets through a more nuanced understanding of the dynamics of carbon balance and permanence over time significantly reduces both the area where woodland expansion is an additional and efficient land-use change and its potential contribution to Scotland's net-zero targets.