Burning of fossil fuels causes emission of greenhouse gases such as carbon dioxide (CO2), which contributes to global warming. Carbon footprints measure how much carbon a person or entity produces. When people or entities try to reduce their carbon footprint or become carbon neutral, they try to cut their emissions and switch to renewable energy.
Purchasing carbon offsets can compensate the remaining emissions. Offsets are typically achieved through financial support of projects in developing countries that reduce the emission of greenhouse gases. These projects usually involve renewable energy or energy efficiency interventions. One carbon offset, often called a carbon credit, represents one tonne of CO2.