Is decoupling enough to achieve the U.S. climate targets for agriculture and forestry? Historical greenhouse gas and biomass fluxes from AFOLU sector production in the United States, 1910–2022
研究了1910-2022年美国农业和林业部门的生产与温室气体动态，发现部分脱钩已实现，但仅靠脱钩不足以达成气候目标，需减少畜牧生产和消费。
The U.S. have committed to a 35 % decrease of non-CO 2 greenhouse gas (GHG) emissions (CH 4 , N 2 O) by 2030. Around half of these emissions stem from the AFOLU sector (agriculture forestry, and other land-use), while forests sequester CO 2 through biomass growth. Efforts have centred on efficiency improvements to decouple biomass production from emissions. The goal of this study is to 1.) quantify the AFOLU sector's production and GHG dynamics between 1910 and 2022, 2.) conduct a decoupling analysis of sectoral and product trends, yearly and cumulatively, 3) evaluate how past and ongoing trends of decoupling compare to land-based climate mitigation targets. Key GHG emission sources include livestock and crop production. The AFOLU sector's annual GHG balance fluctuated between sinks and sources but cumulatively the sector emitted slightly less (42,914 Megatonnes CO 2 equivalents, MtCO 2 e) than it sequestered (−44,130 MtCO 2 e). Partial decoupling was achieved, driven by forestry dynamics, efficiency gains in livestock production, and shifts to less emission-intensive products. However, decoupling has been inconsistent, and increased agricultural production has offset efficiency gains. To achieving climate targets solely through decoupling would require emissions to fall 50 % stronger than they currently do. Our findings support research suggesting that sufficiency measures e.g. reducing livestock production and consumption are necessary to decouple food provision from GHG emissions.