China is now the world's biggest annual emitter of greenhouse gases with 7467 million tons (Mt) carbon dioxide equivalent (CO2e) in 2005, with agriculture accounting for 11% of this total. As elsewhere, agricultural emissions mitigation policy in China faces a range of challenges due to the biophysical complexity and heterogeneity of farming systems, as well as other socioeconomic barriers. Existing research has contributed to improving our understanding of the technical potential of mitigation measures in this sector (i.e. what works). But for policy purposes it is important to convert these measures into a feasible economic potential, which provides a perspective on whether agricultural emissions reduction (measures) are low cost relative to mitigation measures and overall potential offered by other sectors of the economy. We develop a bottom-up marginal abatement cost curve (MACC) representing the cost of mitigation measures applicable in addition to business-as-usual agricultural practices. The MACC results demonstrate that while the sector offers a maximum technical potential of 402 MtCO2e in 2020, a reduction of 135 MtCO2e is potentially available at zero or negative cost (i.e. a cost saving), and 176 MtCO2e (approximately 44% of the total) can be abated at a cost below a threshold carbon price ≤¥ 100 (approximately €12) per tCO2e. Our findings highlight the relative cost effectiveness of nitrogen fertilizer and manure best management practices, and animal breeding practices. We outline the assumptions underlying MACC construction and discuss some scientific, socioeconomic and institutional barriers to realizing the indicated levels of mitigation.
This study is supported by the project “Integration and demonstration of key carbon sequestration and mitigation technologies in the agricultural ecosystems” funded by the Chinese Ministry of Science and Technology (2013BAD11B03), the UK-China Sustainable Agriculture Innovation Network projects and the Research Initiative “Agriculture, Forestry and Climate Change” of the Climate Economics Chair of Paris-Dauphine University. We thank Prof. Weifeng Zhang at the China Agricultural University and Prof. Xiaoyuan Yan at the Institute of Soil Science Nanjing of Chinese Academy of Sciences for providing valuable insights to cropland mitigation potential, Dr. Yan Jun (Center for Chinese Agricultural Policy of Chinese Academy of Sciences) for providing CAPSiM model results, and Valentin Bellassen at CDC Climat for critical review and comments. Dominic Moran acknowledges funding from Scottish Government Rural and Environmental Science and Analytical Services division through ClimatexChange (http://www.climatexchange.org.uk/) and EU funding to FP7 project AnimalChange under the grant agreements no. 266018. Frank Koslowski acknowledges the EU FP7 Marie Curie ITN Action project GREENHOUSEMILK (grant agreement no. 238562) for funding this study.
- climate change
- greenhouse gas mitigation
- marginal abatement cost curve (MACC)