We study the long-term impact of climate change on economic activity across countries, using a stochastic growth model where productivity is affected by deviations of temperature and precipitation from their long-term moving average historical norms. Using a panel data set of 174 countries over the years 1960 to 2014, we find that per-capita real output growth is adversely affected by persistent changes in the temperature above or below its historical norm, but we do not obtain any statistically significant effects for changes in precipitation. We also show that the marginal effects of temperature shocks vary across climates and income groups. Our counterfactual analysis suggests that a persistent increase in average global temperature by 0.04 °C per year, in the absence of mitigation policies, reduces world real GDP per capita by more than 7 percent by 2100. On the other hand, abiding by the Paris Agreement goals, thereby limiting the temperature increase to 0.01 °C per annum, reduces the loss substantially to about 1 percent. These effects vary significantly across countries depending on the pace of temperature increases and variability of climate conditions. The estimated losses would increase to 13 percent globally if country-specific variability of climate conditions were to rise commensurate with annual temperature increases of 0.04 °C.

我们研究长期气候变化对各国经济活动的影响，使用随机增长模型，其中生产力受到温度和降水与其长期移动平均历史规范的偏差的影响。使用 1960 年至 2014 年间 174 个国家的面板数据集，我们发现人均实际产出增长受到高于或低于其历史常值的温度持续变化的不利影响，但我们没有获得任何统计上的显着影响降水的变化。我们还表明，温度冲击的边际效应因气候和收入群体而异。我们的反事实分析表明，如果没有缓解政策，全球平均气温每年持续上升 0.04 °C，到 2100 年，世界人均实际 GDP 将减少 7% 以上。另一方面，遵守《巴黎协定》的目标，从而将温度升高限制在每年 0.01°C，将损失大幅降低到 1% 左右。根据温度升高的速度和气候条件的变化，这些影响在各国之间差异很大。如果特定国家的气候条件变化与年温度升高 0.04 °C 相称，那么估计的全球损失将增加到 13%。