A Framework for Considering the Carbon and Health Co-Benefits of Afforestation and Avoided Forest Conversion

Abstract

Ecosystem services frequently overlap. Natural climate solutions (NCS) can significantly contribute to carbon dioxide equivalent (CO2e) emissions reduction goals by increasing carbon storage and preventing CO2e emissions from forests, wetlands, grasslands, and agricultural lands. Implementation of certain NCS, particularly afforestation and avoided forest conversion, can also provide co-benefits that support human health. However, co-benefit analyses of NCS pathways are rare, which can lead to an underestimation of the value of these NCS pathways and the development of land management plans that overlook opportunities to make progress across multiple objectives. Here, we begin to address this gap by developing a framework for prioritizing areas on the landscape to achieve two management objectives: (1) maintain or increase the capacity to sequester carbon, and (2) reduce adverse human health outcomes through exposure to green space. Using the Puget Sound region as a case study, we operationalize the framework and explore the benefits for human health disparities and carbon storage, explicitly considering co-benefits when developing implementation plans for NCS. Our analysis revealed that census tracts in less developed areas in the Puget Sound region are relatively high priority for maintaining existing carbon storage, and the same is true of the spatial distribution of the priority of census tracts for maintaining existing carbon storage and simultaneously supporting human health. Conversely, census tracts in and around metropolitan areas in the Puget Sound region are relatively high priority for augmenting carbon sequestration through afforestation, supporting human health, and augmenting carbon sequestration while simultaneously supporting human health. Our analyses highlight that varying the objectives of management actions can generate very different spatial patterns of places where management should be prioritized, and these divergent spatial patterns impact the ability of management actions to achieve specific outcomes.