This lecture explores the carbon cycle, focusing on CO2 storage in different reservoirs like the atmosphere, oceans, and rocks, as well as volcanic emissions. It delves into the impact of human activities on the carbon cycle, including the burning of fossil fuels and deforestation, and discusses the potential solutions for reducing CO2 emissions through nature-inspired strategies like weathering and photosynthesis. The lecture also covers the historical trends of atmospheric CO2 levels, the greenhouse effect, and the role of CO2 in influencing the Earth's temperature over time.