Atmospheric warming is not evenly spread around the world. Analysis of historical records suggests that the temperature of land areas will increase more rapidly than the global average. The greatest warming has occurred in the high northern latitudes, especially in northern Canada and Alaska. The map below shows differences between surface temperatures in 2001 and average global temperatures calculated for the period from 1951 to 1980.

7. Which hemisphere (north or south) appears to have experienced the most significant temperature changes? Suggest why this is so.