Global Warming: Where and When?

I've posted before about the importance of the time of year and the regions where temperatures are rising. Apparently, the carbon theory of warming has a prediction which is refuted by the evidence, an article in the Australian says (hat tip: Volokh and Powerline):

1. The greenhouse signature is missing. We have been looking and measuring for years, and cannot find it. Each possible cause of global warming has a different pattern of where in the planet the warming occurs first and the most. The signature of an increased greenhouse effect is a hot spot about 10km up in the atmosphere over the tropics. We have been measuring the atmosphere for decades using radiosondes: weather balloons with thermometers that radio back the temperature as the balloon ascends through the atmosphere. They show no hot spot. Whatsoever.

I've heard before about the prediction of the carbon theory that the warming should occur in the upper atmosphere first. I used to think that one carbon prediction that is true is that warming shoudl occur in arid cold areas in winter first, because there is so little water vapor that a small amount of CO2 makes a bigger difference. I realize now, though, that any theory might predict that, because a little initial warming would result in more water vapor and more warming effect there.