Surface temperature is usually treated as a single mean value in most of the current global warming research.In response to this situation,based on the analysis of surface temperature spatiotemporal distribution characteristic,the radiative forcings of CO₂,CH₄ and so on were calculated and predicted by two ways:by the averaged surface temperature and by its spatiotemporal integration according to its spatiotemporal difference respectively.The results show that the radiative forcing of CO₂ is affected by computation method most,with the absolute difference of the two methods of 0.12 W/m²,which is equivalent to 6% deviation.What's more,the deviation will increase further with the increase of CO₂ atmospheric concentration.As far as trace greenhouse gases such as CH₄ and so on are concerned,even if the concentrations increase substantially,the spatiotemporal difference will not affect their radiative forcings markedly.The radiative forcing of CH₄ is about 25% of that of CO₂ at present,but the yearly increasing rate of CH₄'s radiative forcing is lower than that of CO₂ greatly,so if the concentration growth of CH₄ can be controlled within 1 μL/m³,CH₄'s radiative forcing will be almost invariable with time,and will only amount to 11% of that of CO₂ after 100 years.