Weber Maridee, Wise Marshall, Lamers Patrick, Wang Yong, Avery Greg, Morris Kendalynn A, Edmonds Jae
Joint Global Change Research Institute (Pacific Northwest National Laboratory and University of Maryland), University Research Court, College Park, MD, USA.
National Renewable Energy Laboratory, Denver W Pkwy, Golden, CO, 15013, USA.
Carbon Balance Manag. 2024 Jun 14;19(1):18. doi: 10.1186/s13021-024-00256-2.
Achieving a net zero greenhouse gas United States (US) economy is likely to require both deep sectoral mitigation and additional carbon dioxide removals to offset hard-to-abate emissions. Enhancing the terrestrial carbon sink, through practices such as the adoption of no-till and cover cropping agricultural management, could provide a portion of these required offsets. Changing domestic agricultural practices to optimize carbon content, however, might reduce or shift US agricultural commodity outputs and exports, with potential implications on respective global markets and land use patterns. Here, we use an integrated energy-economy-land-climate model to comprehensively assess the global land, trade, and emissions impacts of an adoption of domestic no-till farming and cover cropping practices based on carbon pricing.
We find that the adoption of these practices varies depending on which aspects of terrestrial carbon are valued. Valuation of all terrestrial carbon resulted in afforestation at the expense of domestic agricultural production. In contrast, a policy valuing soil carbon in agricultural systems specifically indicates strong adoption of no-till and cover cropping for key crops.
We conclude that under targeted terrestrial carbon incentives, adoption of no-till and cover cropping practices in the US could increase the terrestrial carbon sink with limited effects on crop availability for food and fodder markets. Future work should consider integrated assessment modeling of non-CO greenhouse gas impacts, above ground carbon storage changes, and capital and operating cost considerations.
美国要实现温室气体净零排放的经济目标，可能既需要各部门深度减排，又需要额外去除二氧化碳以抵消难以减排的排放。通过采用免耕和覆盖作物种植等农业管理措施来增强陆地碳汇，可以提供部分所需的抵消量。然而，改变国内农业做法以优化碳含量，可能会减少或改变美国农产品的产量和出口，对各自的全球市场和土地利用模式产生潜在影响。在此，我们使用一个综合的能源-经济-土地-气候模型，全面评估基于碳定价采用国内免耕农业和覆盖作物种植做法对全球土地、贸易和排放的影响。
我们发现，这些做法的采用情况因对陆地碳的重视方面不同而有所差异。对所有陆地碳进行估值会导致造林，以牺牲国内农业生产为代价。相比之下，一项专门重视农业系统土壤碳的政策表明，关键作物将大力采用免耕和覆盖作物种植。
我们得出结论，在有针对性的陆地碳激励措施下，美国采用免耕和覆盖作物种植做法可以增加陆地碳汇，对粮食和饲料市场的作物供应影响有限。未来的工作应考虑对非二氧化碳温室气体影响、地上碳储存变化以及资本和运营成本因素进行综合评估建模。
