evidence: Eli’s already covered this but I thought I would present a slightly different argument. The topic is a recent paper by Ned Nikolov and Karl Zeller called new insights on the physical nature of the atmospheric greenhouse effect deduced from an empirical planetary temperature model, an earlier version of which was retracted because they had published under pseudonyms (reversing the letters in their names). [...] Okay, so what about the actual Earth. Well, the surface of the Earth radiates almost 400 Wm-2. This is considerably more than the energy that we receive from the Sun. In the absence of an atmospheric greenhouse effect, the surface would be cooling rapidly, but it obviously does not. [...] So, we can be very confident that Nikolov and Zeller’s argument that planetary surface temperature is set by pressure alone is wrong. Not only does pressure alone not define temperature, in the absence of a planetary greenhouse effect the surface should radiate as much energy as it receives from the Sun, which is clearly not the case for the Earth. The only way to explain why the surface radiates more energy than it gets from the Sun is because of the atmospheric greenhouse effect (to be clear, the surface radiates more than it gets from the Sun, but the planet radiates – into space – the same, on average, as it gets from the Sun). Also, if we add additional greenhouse gases to the atmosphere – as we are currently doing – then we’ll cause the surface to warm even more, as is currently happening.