Global soil organic carbon changes and economic revenues with biochar application. Issue 3 (24th December 2021)

• Record Type: Journal Article
• Authors: Han, Mengjie; Zhao, Qing; Li, Wei; Ciais, Philippe; Wang, Ying‐Ping; Goll, Daniel S.; Zhu, Lei; Zhao, Zhe; Wang, Jingmeng; Wei, Yuan; Wu, Fengchang
• Is Part Of: Global change biology. Volume 14:Issue 3(2022)
• Page Start: 364
• Page End: 377
• Publication Date: 2021-12-24
• Subjects: biochar -- climate change -- economic revenue -- life cycle analysis -- random forest -- SOC; Biomass energy -- Periodicals; Biomass energy -- Environmental aspects -- Periodicals; Energy crops -- Periodicals; 662.88
• DOI: 10.1111/gcbb.12915
• Languages: English
• ISSNs: 1757-1693

Abstract

Abstract: Biochar has been proposed as a promising negative CO2 emission technology to mitigate future climate change with the additional benefit of increasing agricultural production. However, the spatial responses of soil organic carbon (SOC) to biochar addition in cropland are still uncertain, and the economic feasibility of large‐scale biochar implementation remains unclear. Here, we analyzed the response of SOC to biochar addition using 389 paired field measurements. The results show that biochar addition significantly increased SOC by 45.8% on average with large regional variations. Using a random forest model trained with soil, climate, biotic, biochar, and management factors, we found that the response of SOC to biochar addition was mainly dependent on biochar application rates, initial SOC, edaphic (e.g., pH), and climatic (e.g., mean annual precipitation) variables. Combined with the predicted SOC changes to biochar addition on the global cropland, we assessed the revenue of the biochar system based on the current and potential pyrolysis plants in the world using the life‐cycle analysis. Net revenue of the currently existing 144 pyrolysis plants increases with larger plant capacity and higher carbon price. Potential revenue of building new plants is high in regions like America and Europe but low in regions with infertile soil, low crop residues availability, and inconvenient transportation. The global CO2 removal of biochar application is 6.6 Tg CO2 e (CO2 equivalent) year −1 with a net revenue of $ 177 million dollars at a carbon price of $ 50 t −1 CO2 for current pyrolysis plants with a biomass‐processing capacity of 20, 000 t year −1 . Our study provides a full economic assessment of idealized biochar addition scenarios and identifies the locations with maximal potential revenues with new pyrolysis plants. Abstract : This study explores the response of global soil organic carbon (SOC) to biochar application using a machine learning method and evaluates the economic revenues of biochar system based on current and potential pyrolysis plants using the life‐cycle analysis. Biochar addition significantly increased SOC by 45.8% on average with large regional variations. Potential revenue of building new plants is high in regions like America and Europe but low in regions with low crop residues availability and inconvenient transportation (e.g., Africa). The assessment of global biochar implementation has important influence on achieving both national and global CO2 emissions reduction targets.