Anthromes, CO2 and Terrestrial Carbon – Session 7: CO2-fertilization and human land-use contributions to future terrestrial carbon storage

I led the assessment of land-based mitigation potentials in the IPCC land chapter. Studies show that the land sector provides readily available mitigation potential today. Mitigation potentials calculate the scale of emission reductions and sequestration against a counterfactual scenario. For the IPCC, we assessed mitigation potentials from both sectoral studies and integrated assessment models.

We looked at technical potential, which is the maximum biophysical potential or amount possible with current technologies, as well as economic potential across various carbon prices. The cost-effective potential between 2020 and 2050 is 8 to 14 gigatons of CO2 equivalent. The lower range is the median value from the integrated assessment models, and the higher range is the median value from the sectoral studies. This 8 to 14 gigatons is 24 to 42% of the maximum technical potential available.

Cost-effective potential is the potential available up to $100 per ton of carbon, which is considered cost-effective because it's the median carbon price in 2030 and is lower than average in 2050 for a 1.5-degree pathway. These economic potentials are the most relevant for policymakers as it approximates feasibility.

The biggest source of variation in these estimates is in the types of potential, technical versus economic, as well as different approaches for estimation.