Carbon removals from nature restoration are no substitute for steep emission reductions
This study calculates for the first time median carbon removal estimates from five nature-bases pathways across five global regions, producing an annual time series using a basic Monte Carlo method. Constrained restoration options result in a median of 103 GtC removal 2020-2100.
Study link: One Earth, Cell Press (2022)
Growing commitments to net-zero emissions by 2050 to achieve the Paris Agreement goals are a welcome step forward on climate action but have also seen an increasing focus on nature restoration to remove carbon dioxide from the atmosphere. This risks over-relying on land for mitigation at the expense of phasing out fossil fuels. At the same time, a wide range of activities are being labeled “nature restoration,” some of which, such as monoculture tree plantations, degrade nature—destroying biodiversity, increasing pollution, and removing land from food production.
The role of nature restoration in mitigating the impacts of climate change is receiving increasing attention, yet the mitigation potential is often assessed in terms of carbon removal rather than the ability to meet temperature goals, such as those outlined in the Paris Agreement. This study estimates the global removal potential from nature restoration constrained by a “responsible development” framework and the contribution this would make to a 1.5°C temperature limit. The restoration efforts are summed across five global regions, totaling a median of 103 GtC (5%–95% range of −91 to 196 GtC) in cumulative removals between 2020 and 2100.
When combined with deep-decarbonization scenarios, the resulting greenhouse scenario briefly exceeds 1.5°C before declining to between 1.25°C and 1.5°C by 2100 (median, 50% probability), revealing that land restoration is an important option for tackling climate change but cannot compensate for delays in reducing fossil fuel emissions. Quantifying the resultant carbon uptake and temperature impacts shows that nature restoration can marginally lower peak warming, but any climate benefits are dwarfed by the scale of ongoing fossil fuel emissions.
Lead researcher: Kate Dooley, University of Melbourne (U Melbourne)
Contributing researchers: Zebedee Nicholls (IIASA), Malte Meinshausen (U Melbourne)