A carbon footprint is the total amount of greenhouse gases (GHGs), primarily carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O), emitted directly or indirectly by human activities. Measured in tons of CO₂-equivalent, it reflects the environmental impact of everything from driving a car to eating a meal (EPA). With global CO₂ levels exceeding 420 ppm—the highest in […]