The Carbon Cycle: A Global Perspective

This lecture explores the carbon cycle, the most significant biogeochemical cycle involving exchanges between the atmosphere, geosphere, biosphere, and hydrosphere, with a significant impact on climate. It covers the constant cycling of carbon through various processes like photosynthesis, respiration, biodegradation, and biomineralization. The distribution of carbon in different reservoirs such as rocks, oceans, soils, atmosphere, and land plants is discussed, along with the major carbon fluxes and rates. Additionally, the lecture delves into the microbiological carbon cycle, highlighting the extensive transformation of carbon through oxidative and reductive pathways, including the production of methane. The complex interplay between the carbon cycle, nitrogen cycle, and sulfur cycle is also examined, emphasizing the challenges in predicting global cycles and understanding their importance in shaping life on Earth.