建设项目温室气体环境影响评价方法研究

建立完善的、减污降碳相协同的管理制度是支撑全国碳排放高质量达峰的重要保障，有效控制新增碳排放是推动实现重点行业尽早达峰的关键. 环境影响评价是我国源头防控的基础性制度，将温室气体管控要求纳入其中是现阶段推动减污降碳协同增效的可行途径及重要抓手. 综合考虑国内外管理实践经验以及我国制度特点与管理需求，开展了温室气体环境影响评价技术方法研究. 本文提出了系统性、全过程、协同性的三大温室气体评价基本原则，识别建设项目温室气体环境影响评价的主要影响因素，构建了强调高效、低碳、循环的温室气体环境影响评价指标体系，建立了包含项目分析与判断、影响因素识别、影响预测与技术分析、综合环境影响评价的评价方法体系. 基于该方法，以山东省250万吨电解铝产能转移至云南省项目为例，开展碳排放环境影响评价分析，测算结果表明:若不考虑项目对云南省对外输电的影响，全国CO₂减排量可达2 574.4×104 t；如考虑项目对跨区输电的影响，则全国CO₂净减排量将减至968.3×104 t；进一步考虑技术升级、地方煤炭消费政策等因素影响，还会得到差异明显的评价结果. 研究显示,考虑不同评价目标、评价边界和影响因素可能会对全社会碳排放量环境影响评价结果产生显著影响，由此建议在开展相关评价时应立足实际需求，合理确定评价目标和边界. 

Method of Greenhouse Gas Environmental Impact Assessment for Construction Projects

Establishing a sound regulatory system that synergistically controls environmental pollution and greenhouse gas (GHG) emissions is an important basis for achieving a high-quality peak in China's carbon dioxide (CO₂) emissions. Effective control of additional CO₂ emissions is the key for key industrial sectors to reach their peak carbon emissions ahead of the schedule. In China, environmental impact assessment (EIA) is a basic policy for the prevention and control of environmental pollution source. Incorporating GHG emission regulation into the existing EIA system is a feasible and important way for a synergetic control of environmental pollution and GHG emissions. Given this management requirement, we propose an approach to incorporate GHG emission regulations into the EIA for construction projects in China, with implications from domestic and foreign management practices considered. Basic principles for EIA on GHG emissions are proposed, that is, conducting assessments in systemic, whole-process, and synergetic manners. In addition, key factors that will affect GHG emissions of construction projects are identified. We further establish an index system, which emphasis high efficiency, low carbon, and recycling, for the assessment. The assessment procedure is then proposed, including project analysis, influencing factors identifications, impact predictions and technical analysis, and comprehensive environmental impact assessments. Based on the proposed approach, this study evaluated the potential changes in the national CO₂ emissions induced by a project that plans to transfer 250×104 t of electrolytic aluminum production capacity from Shandong Province to Yunnan Province. It is estimated that the national CO₂ emission could be reduced by 2574.4×104 t, when the impacts of inter-regional power transmission from Yunnan Province is not considered. In contrast, when considering this impact of inter-regional power transmission, the national net CO₂ emission reduction is estimated to be 968.3×104 t. Furthermore, if more factors, such as technological upgrading and local coal consumption policies, are taken into account, substantially different assessment results could be obtained. The proposed approach for EIA on GHG emissions can provide a theoretical basis for the establishment of relevant regulatory systems in China. The case analysis indicates that the estimated changes in the CO₂ emissions could differ substantially when considering different assessment objectives, assessment boundaries, and influencing factors, implying that the evaluation objectives and boundaries should be reasonably determined based on project realities and overall requirements.