If you examine the detailed temperature records that form the basis for our understanding of global warming, there are some strange anomalies (at least from a naive point of view where warming affects everywhere equally).
For example, by far the largest temperature increases are confined to winter months in the northern hemisphere. As one commentator has it:
Winter months in the Northern Hemisphere are responsible for most of the observed land warming in CRUTEM4. The summer months (June, July, August, September) essentially show no warming at all from 1850 to 1990. Overall, NH winters have warmed about twice as much as NH summers.
...The same exercise for the southern hemisphere shows very little difference where of course the seasonal months are inverted.
Is there a sensible explanation of this effect? Is it reproduced, for example, in climate models?