Dynamic modelling shows substantial contribution of ecosystem restoration to climate change mitigation
The first study to provide spatially and temporally explicit estimates of ecosystem restoration potential quantified with a Dynamic Global Vegetation Model (DGVM), covering forest restoration, reforestation, reduced harvest, agroforestry and silvopasture.
Report link: Environmental Research, IOP Science (2021)
Limiting global warming to a 1.5°C temperature rise requires drastic emissions reductions and removal of carbon-dioxide from the atmosphere. Most modelled pathways for 1.5°C assume substantial removals in the form of biomass energy with carbon capture and storage, which brings with it increasing risks to biodiversity and food security via extensive land-use change. Recently, multiple efforts to describe and quantify potential removals via ecosystem-based approaches have gained traction in the climate policy discourse. However, these options have yet to be evaluated in a systematic and scientifically robust way.
A series of high-profile papers have built these expectations for large-scale sequestration and storage of carbon dioxide in terrestrial ecosystems. These studies rely on large reforestation areas (678 Mha to 900 Mha). Critique of large-scale tree planting as a climate mitigation strategy ranges from afforestation of non-forest biomes, lack of accounting for soil carbon in the baseline, incorrect consideration of the global carbon cycle, unusually large per-hectare sequestration rates, and overlooking environmental or socioeconomic constraints such as (re)converting land from existing uses (e.g. agriculture, forestry).
This analysis provides the first spatially and temporally explicit estimates of ecosystem restoration potential quantified with the Dynamic Global Vegetation Model (DGVM) JULES. Simulations covering forest restoration, reforestation, reduced harvest, agroforestry and silvopasture were combined and found to sequester an additional 93 Gt C by 2100, reducing mean global temperature increase by ∼0.12°C (5%–95% range 0.06°C–0.21°C) relative to a baseline mitigation pathway. Ultimately, pathways to achieving the 1.5°C goal garner broader public support when they include land management options that can bring about multiple benefits, including ecosystem restoration, biodiversity protection, and resilient agricultural practices.
Lead researcher: Emma Littleton, University of Exeter (U Exeter)
Contributing authors: Kate Dooley (U Melbourne), Gordon Webb (U Melbourne), Anna Harper (U Exeter), Tom Powell (U Exeter), Zebedee Nicholls (IIASA), Malte Meinshausen (U Melbourne), Timothy Lenton (U Exeter)