2011-12-06 09:29:28A little bit of warming would NOT be a good thing


How often have you heard the canard, "I could use a little wamer weather.  Bring it on."?

Let's play along with the idea that the earth is gradually getting uniformly warmer and see where it leads, combining this idea with some of the data from Dr. James Hansen's recent paper "Climate Variability and Climate Change: The New Climate Dice" which can be found at http://www.columbia.edu/~jeh1

From the Hansen paper, we take the baseline distribution of local anomalies, which follow a normal distribution.  In this distribution, an area under the curve represents a percentage of earth's surface.  The area to the right of 3 standard deviations is the percentage of earth's surface that would typically experience an "extremely hot" summer.

For the period 1951-1980, this area is about 0.1%

For the last 10 years, when summer temperatures are compared to the baseline period, this area is about 5 - 10%.

Now suppose we go along with the idea that every part of the earth is gradually warming at the same rate.  This would mean the original baseline distribution is slowly sliding to the right. {NOT QUITE!}  Guess what happens to the area of earth that is expected to be extremely hot during the summer?

It's a "George of the Jungle" kind of moment.  Hey, watch out for that ... HOCKEY STICK !!!!



Note added 12-6-2011: Sorry for the big jumps in steps here.  The last step is not quite right.  Even warming does not translate directly to a shift in the curve as implied.

I will need to spend a bit more time on this to tune it up.  I believe the Hansen paper is EXTREMELY important, and I also think the data presented strongly suggests we should expect to see an effect like the one in the curve.

A simpler example along the same lines is the way in which the percentage of people with IQ over 145 would increase if the curve were shifted.  As in this sequence of curves: