This lecture by the instructor covers the basics of climate economics, focusing on greenhouse gases, climate scenarios, and the mitigation game. It delves into the role of the IPCC, economic topics related to climate change, and the impact of human decisions on emissions. The presentation also discusses the main publications of the IPCC, the confidence and likelihood scales used in climate change assessments, and the different economic drivers behind emissions scenarios. Furthermore, it explores the concept of tipping points in the climate system and concludes with insights on global greenhouse gas emissions trends and the importance of addressing uncertainties in climate economic analysis.