DEFRA Embedding Economics into the Fourth UK Climate Change Risk Assessment

本研究项目的目的是确保和改进政府主导的气候风险评估中嵌入的经济和社会研究方法，并最大限度地发挥英国采取的适应行动的影响。目前，在英国和全球范围内，气候变化适应和复原力建设方面的投资严重不足。因此，这些干预措施的高效益没有实现。这种投资不足的驱动因素包括缺乏关于风险、解决这些风险的成本以及这样做的全部好处的充分信息。了解适应和复原力建设干预措施的成本并全面考虑其益处，可以使政府、国际金融机构和私营部门做出更好的投资决策，缩小融资缺口。先前的研究表明，许多类型的适应投资的全部效益远远大于通常的假设——即使它们所保护的极端事件没有发生，也会在很大程度上产生效益——在此基础上，本奖学金期间进行的研究旨在通过纳入扩展和改进的成本效益分析（CBA）来支持英国第四次气候变化风险评估（CCRA4）——包括事前和事后的成本效益分析（CBA）——以适应和恢复力建设。我打算用多标准分析和事后影响分析/评价来补充这一点。重要的是，我打算把经济和金融评估的三重红利方法作为我工作的核心，这有助于扩大适应投资。CBA广泛应用于公共和私营部门以及国际金融机构（IFIs）对干预措施进行事前评估和事后影响评估。在过去二十年中，由于数据可用性、无形利益的存在以及缺乏方法专业知识等方面的挑战，政府和国际金融机构（如世界银行）开展的CBA的质量有所下降。然而，由于其在项目评估和影响评估以及评估碳排放等外部性（利用碳的社会成本）方面的核心作用，它的使用正在恢复。弹性三重红利（TDR）方法利用CBA来改进适应投资的效益估算。TDR考虑并量化了适应气候变化的全部经济、环境和社会效益。它将效益划分为三个红利：避免损失（第一红利）、诱导的经济或发展效益（第二红利）以及适应行动的额外社会和环境效益（第三红利）。第二和第三红利尤其重要，因为无论实际的气候风险是否成为现实，它们都会产生。Heubaum等人（2021）的研究表明，这些收益的量化导致收益-成本比（bcr）远远高于通常的假设。风险评估能够更好地量化和显示干预的诸多好处，有助于政府解决缓解气候变化与适应气候变化投资之间持续存在的不平衡，并证明利用有限资源促进私营部门投资是合理的。Heubaum， H. et al.（2022）。建设气候适应能力的三重红利：评估、前进。世界资源研究所工作文件。华盛顿特区：世界资源研究所。https://www.wri.org/research/triple-dividend-building-climate-resilience-taking-stock-moving-forward

The aim of this research project is to ensure and improve the embedding of economic and social research methods in government-led climate risk assessments and maximise the impact of adaptation actions undertaken in the UK. There is currently significant under-investment in climate change adaptation and resilience-building, both in the UK and globally. As a consequence, the high benefits of such interventions are not realized. Drivers of this under-investment include a lack of full information on risks, on the costs of addressing those risks, and on the complete benefits of doing so. Understanding costs and considering the full range of benefits of adaptation and resilience-building interventions can enable governments, international financial institutions and the private sector to make better investment decisions and close the financing gap. Building on previous work showing that the full benefits of many types of adaptation investments are far greater than often assumed - and largely accrue even if extreme events against which they protect do not occur - the research undertaken during this fellowship is intended to support the UK's fourth Climate Change Risk Assessment (CCRA4) by incorporating expanded and improved cost-benefit analysis (CBA) - both ex-ante and ex-post - for adaptation and resilience-building. I intend to supplement this with multi-criteria analysis and ex-post impact analysis/ evaluation. Importantly, I intend to put at the heart of my work a triple dividend approach into economic and financial assessments which can help facilitate a scaling up of adaptation investments. CBA is widely applied across the public and private sectors as well as by international financial institutions (IFIs) to conduct ex-ante appraisal and ex-post impact assessments of interventions. The quality of CBA conducted within govenment and in IFIs (e.g., the World Bank) has declined over the past two decades due to challenges around data availability, the presence of intangible benefits, and a lack of methodological expertise. Yet its use is resurging due to its central role in project appraisals and impact assessments and in valuing externalities such as carbon emissions (using the social cost of carbon). The triple dividend of resilience (TDR) approach uses CBA to improve benefits estimates of adaptation investments. The TDR accounts for and quantifies the full economic, environmental, and social benefits of climate change adaptation. It groups benefits along three dividends: avoided losses (first dividend), induced economic or development benefits (second dividend), and additional social and environmental benefits (third dividend) of adaptation actions. The second and third dividends are especially important since they accrue regardless of whether the actual climate risk materializes. Research by Heubaum et al. (2021) has shown that the quantification of these benefits leads to benefit-cost ratios (BCRs) far greater than commonly assumed. An assessment of risk which better quantifies and makes visible the many benefits of intervention can help government adress the continued imbalance between climate mitigation and adaptation investments, and justify the use of limited resources to catalyze private sector investment. Heubaum, H. et al. (2022). The Triple Dividend of Building Climate Resilience: Taking Stock, Moving Forward. WRI Working Paper. Washington, D.C.: World Resources Institute. https://www.wri.org/research/triple-dividend-building-climate-resilience-taking-stock-moving-forward