A carbon balance is a tool that counts the greenhouse gas emissions of an activity, of an organisation or of individuals. It is generally expressed in tonnes of CO2 emitted. Amongst other things, a carbon balance helps to highlight an activity's dependence on fossil energies, and hence its economic vulnerability. By quantifying greenhouse gas emissions, a carbon balance also paves the way for carbon offsetting actions (see carbon neutrality). In France, the carbon balance also serves as the basis for calculating the greenhouse gas emissions balance (bilan des émissions de gaz à effet de serre, BEGES), now compulsory for companies with more than 500 employees and local authorities with more than 50,000 inhabitants.