http://seattletimes.nwsource.com/html/businesstechnology/2016794248_apussciclimateextremes.html "Scientists were able to weigh their confidence of predictions of future climate disasters and heat waves were the most obvious. The report said it is "virtually certain" that heat waves are getting worse, longer and hotter, while cold spells are easing. "What that means is the nasty heat wave that used to happen once every 20 years by mid-century will be once every five years and by the end of the century will be an every other year scorcher, Field and Stocker said. "The report said there is at least a two-in-three chance that heavy downpours will increase, both in the tropics and northern regions, and from tropical cyclones." The latest scientific American reports roughly the same prognostication.