Radiative forcing

Radiative forcing ΔF is defined by the IPCC (Intergovernmental Panel on Climate Change) as the change in net irradiance at the tropopause (part of the atmosphere between the troposphere and the stratosphere). Radiative forcing is measured with the year 1750 (the approximate start of the industrial revolution) as standard. A positive forcing (more incoming energy) tends to warm the Earth, while a negative forcing (more outgoing energy) tends to cool it. A positive change in net irradiation can be caused, for instance, by more intense insolation (radiation by the Sun), or by a carbondioxide increase in the atmosphere.