The topics of climate change and climate change policy encompass a complex mixture of the natural sciences, economics, and a mass of institutional, legal, and technical details. This complexity and multidisciplinary nature make it difficult for thoughtful citizens to reach their own conclusions on the topic and for potentially interested economists to know where to start. This essay aims to provide a point of entry formacroeconomists interested in climate change and climate change policy but with no special knowledge of the field. I therefore start at the beginning, with some basic background on climate change, presented through the eyes of an econometrician. I then turn to climate policy in the United States. That discussion points to a large number of researchable open questions that macroeconomists are particularly well suited to tackle. Let me summarize my four main points. First, although a healthy dose of skepticism is always in order (as academics it is in our DNA), simple and transparent time series regression models familiar to macroeconomists provide independent verification of some key conclusions from climate science models and in particular confirm that essentially all the warming over the past 140 years is because of human activity, that is, is anthropogenic. Figure 1 shows time series data on annual global mean temperature since 1860, when reliable instrumental records start. As seen in the figure, the global mean temperature has increased by approximately 1 degree Celsius, compared with its 1870–90 average value. This increase in temperatures drives a wide range of changes in climate, including droughts, more hot days, and more intense rainfalls and storms, all of which vary regionally. Because climate science uses large, opaque calibrated models of the climate system, there is room for confusion among legitimately skeptical outsiders about just howmuch of the global warming observed since the industrial revolution results from human

中文翻译：

---

气候变化、气候政策和经济增长

气候变化和气候变化政策的主题包含自然科学、经济学和大量制度、法律和技术细节的复杂组合。这种复杂性和多学科性质使深思熟虑的公民难以就该主题得出自己的结论，也使潜在感兴趣的经济学家难以知道从哪里开始。本文旨在为对气候变化和气候变化政策感兴趣但没有该领域专业知识的宏观经济学家提供一个切入点。因此，我首先从计量经济学者的角度介绍了气候变化的一些基本背景。然后我转向美国的气候政策。该讨论指出了宏观经济学家特别适合解决的大量可研究的开放性问题。让我总结一下我的四个要点。首先，尽管一定要有适度的怀疑（正如学术界在我们的 DNA 中一样），宏观经济学家熟悉的简单透明的时间序列回归模型提供了对气候科学模型的一些关键结论的独立验证，特别是确认基本上所有过去140年的变暖是因为人类活动，也就是人为。图 1 显示了自 1860 年开始可靠的仪器记录以来全球年平均气温的时间序列数据。如图所示，与 1870-90 年的平均值相比，全球平均温度升高了约 1 摄氏度。气温升高导致气候发生广泛变化，包括干旱、更热的日子以及更强烈的降雨和风暴，所有这些都因地区而异。由于气候科学使用大型的、不透明的气候系统校准模型，因此对自工业革命以来观察到的全球变暖有多少是由人类造成的，持怀疑态度的局外人可能会感到困惑。