No official French source publishes temperature reductions in degrees for each measure. ADEME explicitly acknowledges this: effectiveness depends on urban form, local climate and the combination of solutions, and cannot be reduced to performance for a single intervention. The only published estimate concerns evapotranspiration from a mature tree in a row, at 450 litres per day, equivalent to five air conditioners operating for twenty hours.
Read the source article: Adapting a territory to climate change: the method