Slide 4: What are we looking for?
The expression of changing climatic variables may differ, depending on the manner of climatic transformation. A change in mean temperature would most likely cause us to see more extreme heat, and more hot weather events, as shown in the first graph. However, a transformation in the variance of the temperature would cause the curve to become lower and wider, increasing the incidence of both hot and cold weather events. Most importantly, a change in both variance and mean of temperature might up the incidence of extreme heat and hot weather events, but the incidence of cold weather might be unchanged. This type of change would therefore hide the signal, since certain placers might not receive radically altered weather conditions. The trend would only become clear gradually, and this may be what we have observed in recent history.