Monitoring agroforestry projects over time by remote sensing: dynamic baselines for the quantification of additionality

Afforestation, reforestation and revegetation (ARR) projects, such as converting degraded pasture into agroforestry systems (AFSs), are among the most promising strategies for atmospheric CO2 removal (CDR). As project-related climate change mitigation only exists if CO2 removal would not have occurred in the absence of the project implementation, the ‘additionality’ of each treatment plot needs to be demonstrated. Reliable and cost-efficient monitoring-reporting-verification (MRV) tools are needed to ensure high integrity accounting of climate impacts – especially additionality. Here, we propose a novel approach to select counterfactual proxies for the project area by spectrally matching project areas with control plots. By observing the relative carbon stock regeneration on these control plots dynamically through time, we are able to quantify the proportional additionality, and estimate the marginal benefit of the ARR activity to the climate.