Revising the climate change mitigation potential of natural climate solutions

Many countries aim to meet their climate goals by enhancing carbon uptake in forests, either by expanding forested areas or by restoring sustainable management practices in poorly managed forests. Scientific consensus is growing around the potential of such land-based projects, known as “natural climate solutions (NCS),” to mitigate climate change by removing additional carbon dioxide from the atmosphere. However, these actions impact not only the carbon cycle but also the exchanges of water, energy, and other organic compounds between the land and atmosphere. These interactions change both the temperature and motions of the Earth’s atmosphere in ways that can either amplify or reduce the benefits of the carbon uptake. Ignoring these other crucial mechanisms could lead to climate policies that are suboptimal or even counterproductive. NCS-REVISE aims to quantify these overlooked climate forcings associated with large-scale NCS implementation, revising current mitigation potential estimates that focus solely on carbon-cycle benefits. The project unites land and atmospheric scientists to address this knowledge gap by: 1. Using advanced global climate models and analytical tools to quantify these additional climate forcings linked to NCS; 2. Applying innovative analysis methods to build understanding of specific forcings, their connections to changes in surface properties and processes, their temporal and spatial patterns and uncertainties under climate change, and their potential to impact climate elsewhere; 3. Developing new tools to attribute specific climate forcings to particular NCS types and geographic regions. Through this work, NCS-REVISE will provide a more comprehensive assessment of the climate impacts of NCS, enabling the development of more effective, holistic climate policies.

Natural climate solutions (NCS) – or actions to restore carbon dense land ecosystems in effort to enhance carbon dioxide removal (CDR) – are now widely considered as necessary components in providing the deep emission reductions required to meet ambitious global warming mitigation targets. However, such actions can affect climate via changes to the thermodynamical and dynamical functioning as well as chemical make-up of the atmosphere, resulting in concomitant perturbations to Earth’s radiative energy balance that either reinforce or offset CDR benefits. These parallel forcings have long been recognized as important yet remain absent from assessments of and policies relevant to NCS’ climate change mitigation potential. This is likely owed to difficulties surrounding their quantification and attribution. NCS-REVISE brings together land and atmospheric scientists to fill this critical knowledge gap residing at the interface between the land and atmospheric sciences by: 1) employing state-of-the-art global climate models and conventional diagnostic tools to quantify the BGP and BA radiative forcings and adjustments connected to NCS; 2) applying innovative analysis techniques to build knowledge surrounding specific forcing and adjustment mechanisms, their relationships with perturbed surface properties or processes, their temporal-spatial dependencies and uncertainties under evolving climate change, and their ability to affect climate elsewhere; 3) developing new tools for attribution of BGP/BA forcing and adjustments to specific NCS types and geographic locations.