Commercial afforestation can deliver effective climate change mitigation under multiple decarbonisation pathways

Afforestation is an important greenhouse gas (GHG) mitigation strategy but the efficacy of commercial forestry is disputed. Here, we calculate the potential GHG mitigation of a UK national planting strategy of 30,000hayr(-1) from 2020 to 2050, using dynamic life cycle assessment. What-if scenarios vary: conifer-broadleaf composition, harvesting, product breakouts, and decarbonisation of substituted energy and materials, to estimate 100-year GHG mitigation. Here we find forest growth rate is the most important determinant of cumulative mitigation by 2120, irrespective of whether trees are harvested. A national planting strategy of commercial forest could mitigate 1.64 Pg CO(2)e by 2120 (cumulative), compared with 0.54-1.72 Pg CO(2)e for planting only conservation forests, depending on species composition. Even after heavy discounting of future product substitution credits based on industrial decarbonisation projections, GHG mitigation from harvested stands typically surpasses unharvested stands. Commercial afforestation can deliver effective GHG mitigation that is robust to future decarbonisation pathways and wood uses. Afforestation is an important greenhouse gas (GHG) mitigation strategy but the efficacy of commercial (harvested) forestry is disputed. Here the authors apply dynamic life cycle assessment to show that new commercial conifer forests can achieve up to 269% more GHG mitigation than semi-natural forests, over 100 years.

Automated summary

The study shows that commercial conifer forests can achieve up to 269% more greenhouse gas mitigation than semi-natural forests over 100 years. The growth rate of the forests is the most important factor affecting greenhouse gas mitigation, and typically, harvesting stands have higher mitigation effects compared to unharvested stands.