ENVIR101 Lecture 02 Carbon Cycle Sp2025 PDF

Composition CO2 emerged from geologic events. CO2 became 25% of Atmospheric gases. CO2 consumed when photosynthesis evolved. O2 emerged when photosynthesis evolved. Credit: Wikimedia Commons Composition of the Atmosphere Atoms and Molecules Reservoir and Flux  Residence Tim...

Composition CO2 emerged from geologic events. CO2 became 25% of Atmospheric gases. CO2 consumed when photosynthesis evolved. O2 emerged when photosynthesis evolved. Credit: Wikimedia Commons Composition of the Atmosphere Atoms and Molecules Reservoir and Flux  Residence Time of Carbon Dioxide (Cawley, 2011) 75 years! Fast Carbon Cycle Biosphere — Photosynthesis — Respiration Photosynthesis  Photosynthesis Water and carbon dioxide in the presence of sunlight (solar energy) and chlorophyll (in leaf) yield glucose and oxygen. Glucose is the primary fuel for all metabolic processes Glucose can be used for energy or to make other organic molecules such as other carbohydrates, proteins, fats, and nucleic acids. Photosynthesis is the origin of the energy in all fossil fuels CO2 is chemically reduced to form sugars.