Model - average mean local precipitation responses also roughly scale with the global mean temperature response across the emissions scenarios, though not as well as for temperature. (ipcc.ch)
An equally important variable is the ocean temperature response to increased CO2, which has suffered from large uncertainties. (realclimate.org)
It is known that, in the models at least, not all forcings produce identical temperature responses — some higher than expected from a CO2 equivalent forcing and some lower than expected. (climateaudit.org)