We assess economic costs of heat-induced reductions in worker productivity at global scale under RCP2.6 and RCP8.5. Losses in worker productivity are calculated by using an empirically estimated epidemiological exposure-response function, and the associated economic costs are assessed by using a dynamic multi-region, multi-sector computable general equilibrium model. Autonomous mechanisation of outdoor work in agriculture and construction is implemented in the model. We find that under RCP8.5 by 2100, heat-induced reductions in worker productivity result in an average decline of 1.4% in global gross domestic product (GDP) relative to the reference scenario with no climate change. This is approximately 0.4 percentage points less than when no autonomous mechanisation is assumed. For comparison, measuring the economic costs using occupational health and safety recommendations leads to a 2.4% reduction in global GDP, which is substantially larger than when the epidemiological exposure-response function is used. Countries of Africa, South-East Asia, and South Asia are the worst affected by heat stress. However, economic costs could be substantially alleviated if a 2°C global warming target is achieved. Under RCP2.6, the average reduction in global GDP is only 0.5%. A large fraction of global mitigation costs of achieving the 2°C global warming target could be offset by the avoided adverse impacts of heat stress on worker productivity at higher warming levels.

我们根据RCP2.6和RCP8.5评估了全球范围内由热引起的工人生产率下降的经济成本。通过使用经验估计的流行病学暴露-响应函数来计算工人生产率的损失，并使用动态的多区域，多部门可计算的一般均衡模型来评估相关的经济成本。该模型实现了农业和建筑业户外作业的自主机械化。我们发现，根据RCP8.5，到2100年，与没有气候变化的参考情景相比，热引起的工人生产率下降导致全球国内生产总值（GDP）平均下降1.4％。这比未假设自动机械化时低约0.4个百分点。为了比较，使用职业健康和安全建议衡量经济成本会导致全球GDP减少2.4％，这比使用流行病学暴露-反应功能时要大得多。非洲，东南亚和南亚国家是受热胁迫影响最严重的国家。但是，如果实现2°C的全球变暖目标，则可以大幅降低经济成本。在RCP2.6下，全球GDP的平均减少仅为0.5％。达到2°C全球变暖目标的全球缓解成本的很大一部分可以通过避免高温胁迫下高温对工人生产率产生的不利影响来抵消。东南亚和南亚受热胁迫的影响最严重。但是，如果实现2°C的全球变暖目标，则可以大幅降低经济成本。在RCP2.6下，全球GDP的平均减少仅为0.5％。达到2°C全球变暖目标的全球缓解成本的很大一部分可以通过避免高温胁迫下高温对工人生产率产生的不利影响来抵消。东南亚和南亚受热胁迫的影响最严重。但是，如果实现2°C的全球变暖目标，则可以大幅降低经济成本。在RCP2.6下，全球GDP的平均减少仅为0.5％。达到2°C全球变暖目标的全球缓解成本的很大一部分可以通过避免高温胁迫下高温对工人生产率产生的不利影响来抵消。