The notion that biomass combustion is carbon neutral vis‐a‐vis the atmosphere because carbon released during biomass combustion is absorbed during plant regrowth is inherent in the greenhouse gas accounting rules in many regulations and conventions. But this ‘carbon neutrality’ assumption of bioenergy is an oversimplification that can result in major flaws in emission accounting; it may even result in policies that increase, instead of reduce, overall greenhouse gas emissions. This commentary discusses the systemic feedbacks and ecosystem succession/land‐use history issues ignored by the carbon neutrality assumption. Based on recent literature, three cases are elaborated which show that the C balance of bioenergy may range from highly beneficial to strongly detrimental, depending on the plants grown, the land used (including its land‐use history) as well as the fossil energy replaced. The article concludes by proposing the concept of GHG cost curves of bioenergy as a means for optimizing the climate benefits of bioenergy policies.

中文翻译：

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与生物能源相关的生物碳的净陆地-大气流动：理解系统反馈。

生物质燃烧对大气是碳中性的，因为生物质燃烧过程中释放的碳在植物再生过程中被吸收，这是许多法规和公约的温室气体核算规则所固有的。但这种生物能源的“碳中和”假设过于简单化，可能导致排放核算存在重大缺陷；它甚至可能导致增加而不是减少总体温室气体排放的政策。本评论讨论了碳中和假设忽略的系统反馈和生态系统演替/土地利用历史问题。根据最近的文献，详细阐述了三个案例，这些案例表明生物能源的 C 平衡可能从非常有益到非常有害，具体取决于种植的植物，使用的土地（包括其土地使用历史）以及替代的化石能源。文章最后提出了生物能源温室气体成本曲线的概念，作为优化生物能源政策气候效益的一种手段。