TY - JOUR
T1 - Land-based climate solutions for the United States
AU - Robertson, G. Philip
AU - Hamilton, Stephen K.
AU - Paustian, Keith
AU - Smith, Pete
N1 - Funding Information:
We thank many colleagues for helpful discussion and feedback during the preparation of this analysis, anonymous reviewers for constructive criticism, and J.L. Schuette for help with data assembly. Financial support was provided by the U.S. Department of Energy Great Lakes Bioenergy Research Center (Award DE‐SC0018409), the U.S. National Science Foundation Long‐term Ecological Research Program (DEB 1832042), the USDA Long‐term Agroecosystem Research program, and Michigan State University AgBioResearch. Additional support (PS) is from the Soils‐R‐GGREAT (NE/P019455/1) and CIRCASA (Agreement 774378) projects of the European Union‘s Horizon 2020 Research and Innovation Programme (Award 774378); and (KP) the U.S. Department of Energy Advanced Research Projects Agency‐Energy program (Award DE‐AR0000826). KP serves as a part‐time advisor to Indigo Ag, Inc., a company that markets soil carbon sequestration credits. The authors declare no other potential conflicts of interest.
Publisher Copyright:
© 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.
PY - 2022/8
Y1 - 2022/8
N2 - Meeting end-of-century global warming targets requires aggressive action on multiple fronts. Recent reports note the futility of addressing mitigation goals without fully engaging the agricultural sector, yet no available assessments combine both nature-based solutions (reforestation, grassland and wetland protection, and agricultural practice change) and cellulosic bioenergy for a single geographic region. Collectively, these solutions might offer a suite of climate, biodiversity, and other benefits greater than either alone. Nature-based solutions are largely constrained by the duration of carbon accrual in soils and forest biomass; each of these carbon pools will eventually saturate. Bioenergy solutions can last indefinitely but carry significant environmental risk if carelessly deployed. We detail a simplified scenario for the United States that illustrates the benefits of combining approaches. We assign a portion of non-forested former cropland to bioenergy sufficient to meet projected mid-century transportation needs, with the remainder assigned to nature-based solutions such as reforestation. Bottom-up mitigation potentials for the aggregate contributions of crop, grazing, forest, and bioenergy lands are assessed by including in a Monte Carlo model conservative ranges for cost-effective local mitigation capacities, together with ranges for (a) areal extents that avoid double counting and include realistic adoption rates and (b) the projected duration of different carbon sinks. The projected duration illustrates the net effect of eventually saturating soil carbon pools in the case of most strategies, and additionally saturating biomass carbon pools in the case of forest management. Results show a conservative end-of-century mitigation capacity of 110 (57–178) Gt CO2e for the U.S., ~50% higher than existing estimates that prioritize nature-based or bioenergy solutions separately. Further research is needed to shrink uncertainties, but there is sufficient confidence in the general magnitude and direction of a combined approach to plan for deployment now.
AB - Meeting end-of-century global warming targets requires aggressive action on multiple fronts. Recent reports note the futility of addressing mitigation goals without fully engaging the agricultural sector, yet no available assessments combine both nature-based solutions (reforestation, grassland and wetland protection, and agricultural practice change) and cellulosic bioenergy for a single geographic region. Collectively, these solutions might offer a suite of climate, biodiversity, and other benefits greater than either alone. Nature-based solutions are largely constrained by the duration of carbon accrual in soils and forest biomass; each of these carbon pools will eventually saturate. Bioenergy solutions can last indefinitely but carry significant environmental risk if carelessly deployed. We detail a simplified scenario for the United States that illustrates the benefits of combining approaches. We assign a portion of non-forested former cropland to bioenergy sufficient to meet projected mid-century transportation needs, with the remainder assigned to nature-based solutions such as reforestation. Bottom-up mitigation potentials for the aggregate contributions of crop, grazing, forest, and bioenergy lands are assessed by including in a Monte Carlo model conservative ranges for cost-effective local mitigation capacities, together with ranges for (a) areal extents that avoid double counting and include realistic adoption rates and (b) the projected duration of different carbon sinks. The projected duration illustrates the net effect of eventually saturating soil carbon pools in the case of most strategies, and additionally saturating biomass carbon pools in the case of forest management. Results show a conservative end-of-century mitigation capacity of 110 (57–178) Gt CO2e for the U.S., ~50% higher than existing estimates that prioritize nature-based or bioenergy solutions separately. Further research is needed to shrink uncertainties, but there is sufficient confidence in the general magnitude and direction of a combined approach to plan for deployment now.
UR - http://www.scopus.com/inward/record.url?scp=85130998725&partnerID=8YFLogxK
U2 - 10.1111/gcb.16267
DO - 10.1111/gcb.16267
M3 - Article
AN - SCOPUS:85130998725
VL - 28
SP - 4912
EP - 4919
JO - Global Change Biology
JF - Global Change Biology
SN - 1354-1013
IS - 16
ER -
