PNNL

Abstract

Afforestation and reforestation can contribute to climate change mitigation. However, the globally increasing frequency and intensity of climate extremes will lead to increasing forest disturbances and could affect the efficacy of forestation efforts. In this perspective article, we critically assess the forestation scenarios outlined by five different Integrated Assessment Models (IAMs) and how climate change feedbacks are accounted for in these scenarios. Our effort involves an analysis and quantification of the exposure of forestation maps to fire weather and a detailed overview of the representations of climate change feedbacks to forests. We highlight that few IAMs are currently accounting for such feedbacks and that consequently many projected forestation areas are in regions that are and will be exposed to weather conditions that are increasing the likelihood of fire. We thus argue that the actual climate mitigation potential of forestation in IAM scenarios is subject to substantial uncertainty and that we should try to avoid overly optimistic estimates of negative emission potential of forestation. As a way forward we exemplify how to integrate more detailed climate information when modeling forestation scenarios