Ocean heat uptake efficiency

This is a measure (W m^–2 °C^–1) of the rate at which heat storage by the global ocean increases as global surface temperature rises. It is a useful parameter for climate change experiments in which the radiative forcing is changing monotonically, when it can be compared with the climate sensitivity parameter to gauge the relative importance of climate response and ocean heat uptake in determining the rate of climate change. It can be estimated from a 1% yr^–1 atmospheric carbon dioxide increase experiment as the ratio of the global average top-of-atmosphere net downward radiative flux to the transient climate response (see climate sensitivity).

Definition courtesy of IPCC AR4.