Radiative forcing
A change in Earth's energy balance caused by a factor such as increased greenhouse gases or altered solar input.
Example
Positive forcing tends to warm the climate; negative forcing tends to cool it.
The catch
Forcing describes an energy imbalance, not a direct temperature reading.
Related terms
Greenhouse gas, Albedo, Atmospheric lifetime, Carbon budget, Carbon dioxide, Climate change
In more depth
Radiative forcing, explained.
Radiative forcing lets scientists compare unlike drivers of warming on a common scale, measured in watts per square metre of Earth's surface. IPCC AR6 uses effective radiative forcing, which includes the quick adjustments of clouds and the atmosphere before the surface temperature responds.
Carbon dioxide provides the largest positive forcing since pre-industrial times, followed by methane. Aerosols from air pollution exert a negative forcing that has masked part of the warming. Cleaning the air removes some of that mask even as it saves lives. Climate sensitivity then links a given forcing to the eventual temperature change. Use forcing to compare causes, and keep temperature for describing outcomes.