- Definition of CO₂: A colorless gas with a density about 53% higher than that of dry air. CO₂ molecules absorb and emit infrared radiation, contributing to the greenhouse effect.
- Primary sources: The burning of fossil fuels like coal, oil, and natural gas for energy and transportation, deforestation for agriculture, and industrial processes.
- Impact: The leading driver of climate change, affecting weather patterns, increasing the frequency of extreme weather events, and causing sea-level rise.