Radiative forcing is the warming effect on our climate due to carbon dioxide (CO2) and other heat-trapping greenhouse gases (GHGs). In climate science radiative forcing is the change in net irradiance between different layers of the atmosphere. Typically, radiative forcing is quantified at the tropopause in units of watts per square meter. A positive forcing (more incoming energy) tends to warm the system, while a negative forcing (more outgoing energy) tends to cool it. Sources of radiative forcing include changes in insolation (incident solar radiation) and in concentrations of radiatively active gases and aerosols.
