claim: ( 2009 ) have demonstrated recently  – the upper troposphere ( the only place where adding CO2 to the  atmosphere could make any difference to temperature ) is considerably  drier than the models are tuned to expect.
evidence: The temperatures in the coldest upper region of the troposphere ( the tropopause ) actually vary in the range between 49 and 57 K ( −224 and −216 °C; −371 and −357 °F ) depending on planetary latitude.