James Hansen recently published analysis showing that temperature has increased enough that the probability of extremes (in particular, extreme heat) is significantly greater than it used to be. This has consequences.
We have indeed witnessed a spate of extreme heat events recently: the 2003 European heat wave, the monster Russian heat wave of 2010, Texas/Oklahoma 2011, and this year’s heat/drought in the USA. Hansen emphasized that these extreme events are so much more common that such a concordance simply wouldn’t have happened without global warming. Extremes are 10 times more likely than they used to be. We would of course have heat waves anyway, but global warming has made them distressingly more frequent.
I’ve written a couple of posts dealing with how we have loaded the climate dice, increasing the likelihood of extreme weather events – things that happened once a century are now happening twice a decade.
Here we have some simple math to help demonstrate this. Of course, the simple math included integrals but all you need to understand is the curves.
What they show is what has already been written – just a small change in the temperature mean and the extremes can have a huge effect on damage.
And here is where these weather events will continue to pound the US:
And we will have to pay out tens of billions of dollars to deal with the damages. Climate change will cost of huge amounts of money directly a year, not to mention its economic impacts due to indirect effects, such as less food and water.