Scientific American: Australia had to add a new color to its weather maps this week. Meteorologists used royal purple to denote an off-the-charts high temperature of 50 degrees Celsius (122 degrees Fahrenheit), part of an unprecedented heat wave and ongoing wildfires occurring down under this month. On the other side of the globe, 2012 proved the hottest year on record in the contiguous U.S., surpassing the previous record-holder by a full degree F (0.6 deg C). In short, global warming is continuing to turn up the heat--so...