A carbon footprint is the total amount of greenhouse gas emissions produced directly and indirectly by an individual, organization, event, or product, usually measured in tonnes of carbon dioxide equivalent. Personal carbon footprints include emissions from home energy use, transportation, food consumption, and purchases. Organizational footprints encompass operations, facilities, travel, and supply chains. Many municipalities measure their corporate carbon footprint (from municipal operations) and community carbon footprint (from all activities within municipal boundaries). Understanding carbon footprints helps identify where emissions are highest and where reduction efforts can be most effective. Carbon footprint calculators help individuals estimate their personal emissions.