Codes commonly used in climate and weather prediction models for calculating the transfer of solar radiation in the atmosphere show systematic differences amongst each other, and even the best of codes show systematic differences with respect to observations. A 1-dimensional radiative-convective equilibrium model is used to show the effects of such bias on the global energy balance and on the global response to a doubling of CO2. We find the main impact is in the energy exchange terms between the surface and atmosphere and in the convective transport in the lower troposphere, where it exceeds 10 W m-2. The impact on model response to doubling of CO2, on the other hand, is quite small and in most cases negligible.