220.127.116.11. Latitudinal Surface Temperatures
Most simulations suggest that the warming north of 50�N in the winter half of the year should be enhanced due to ice-albedo feedback mechanisms (Manabe & Stouffer, 1980; Ingram et al., 1989). Over the last 100 years, high northern latitudes have warmed slightly more than the global mean during winter, but since the 1920s there is little noticeable trend (see Figure 6.13). More importantly, however, high-latitude warming does not necessarily represent a unique fingerprint of greenhouse warming. Ice-albedo feedbacks could be equally invoked for other causes of climate change.