A Note on the Economic Cost of Climate Change and the Rationale to Limit it Below 2°C

Hallegatte, Stephane ; Dumas, Patrice ; Hourcade, Jean-Charles

World Bank, Washington, DC

关键词: ADAPTATION ACTIONS;    ADAPTATION COSTS;    ADAPTATION DECISIONS;    ADAPTATION INVESTMENTS;    ADAPTATION STRATEGIES;   

DOI  :  10.1596/1813-9450-5179
RP-ID  :  WPS5179

学科分类：社会科学、人文和艺术（综合）

来源: World Bank Open Knowledge Repository

【 摘 要 】

This note highlights a major reason tolimit climate change to the lowest possible levels. Thisreason follows from the large increase in uncertaintyassociated with high levels of warming. This uncertaintyarises from three sources: the change in climate itself, thechange s impacts at the sector level, and theirmacroeconomic costs. First, the greater the differencebetween the future climate and the current one, the moredifficult it is to predict how local climates will evolve,making it more difficult to anticipate adaptation actions.Second, the adaptive capacity of various economic sectorscan already be observed for limited warming, but is largelyunknown for larger changes. The larger the change inclimate, therefore, the more uncertain is the final impacton economic sectors. Third, economic systems can efficientlycope with sectoral losses, but macroeconomic-level adaptivecapacity is difficult to assess, especially when it involvesmore than marginal economic changes and when structuraleconomic shifts are required. In particular, these shiftsare difficult to model and involve thresholds beyond whichthe total macroeconomic cost would rise rapidly. Theexistence of such thresholds is supported by pastexperiences, including economic disruptions caused bynatural disasters, observed difficulties funding neededinfrastructure, and regional crises due to rapid economicshifts induced by new technologies or globalization. As aconsequence, larger warming is associated with higher cost,but also with larger uncertainty about the cost. Becausethis uncertainty translates into risks and makes it moredifficult to implement adaptation strategies, it representsan additional motive to mitigate climate change.