In the context of the IPCC assessments, radiative forcing refers to an
external perturbation in the radiative energy budget of the Earth’s climate
system, which may lead to changes in climate parameters.
A positive forcing (more incoming energy) tends to warm the
system, while a negative forcing (more outgoing energy) tends
to cool it. This is due to changes in drivers of climate change such as the
concentration of carbon dioxide or the output of the Sun.
In the IPCC reports, changes in radiative forcing are relative to the year
1750.
