Sardeshmukh has weighed in on Curry’s blog:
The critic of our study is mistaken on all counts.
1) Contrary to his suspicion, we did correctly define the temperature extremes with respect to the same fixed temperature threshold in both periods at each geographical point. The formula in the math slide, which is for shape preserving changes of the distribution, is also for exceedances beyond a fixed threshold.
2) As already noted at the bottom of the math slide, “the situation gets even more complicated for non-Gaussian distributiions whose changes are not shape preserving”. And indeed they are not shape preserving for daily temperature. There were changes from 1901-1925 to 1981-2005 in both the skewness and kurtosis (a measure of tail heaviness) at most points on the globe, including the Indian ocean point discussed by the critic. I had mentioned these changes in my talk, but not shown them to save time, as the main point of the slide showing the change in daily temperature extremes from 1901-1925 to 1981-2005 had already been made. This was that the global pattern of the change in extremes does not look anything like that of the mean shift, and this is not surprising given the fractional changes in standard deviation. The point of this slide was not that one could deduce the numerical value of the change in the extremes from only the changes in the mean and standard deviation, but that the changes in standard deviation were clearly important, and opposed the changes in the mean in many regions.
I replied on Curry’s blog with this:
If what you say is true, then I have made a grave mistake. But perhaps you can understand my skepticism that an increase in mean by a full standard deviation, combined with an increase in standard deviation, would accompany no change in the probability of exceeding a fixed temperature threshold.
If you will share with me the data you used for that grid point in the Indian Ocean, I can confirm your results with my own eyes. Upon doing so, I will publish on my blog a prominent, unambiguous admission of my error. But until I see it with my own eyes, I remain skeptical.
I look forward to seeing the data
Well, Judith Curry has “responded” to my last blog post … sort of. Here’s what she has to say about it:
In her recent blog post Judith Curry gave her reasons for not believing that global warming is exacerbating heat waves. Her conclusion was summarized thus:
It has often been rumored that when Marie Antoinette was told that the people of France faced starvation because they had no bread, she replied “Let them eat cake.”
The story isn’t true, but it does encapsulate the kind of cavalier, thoughtless, arrogant thinking that makes people want to cut your head off.
If the people of India and Pakistan were facing starvation, what would we recommend? “Let them eat curry”? Fortunately, they aren’t presently facing terrible food shortages. But thousands of those people — human beings — died as a result of recent killer heat waves. What advice does Judith Curry offer? This:
Looks like they need more air conditioning in Spain and France and also South Asia.
Does it make more sense to provide air conditioning or to limit CO2 emissions. I vote for more air conditioning in these susceptible regions.
Let them buy air conditioners! Never mind that they’re poor and can’t afford it. Ignore the fact that the energy use would make global warming worse. And be sure to paint it as an “either/or” proposition whether it is or not. Just don’t make us do anything like limit CO2 emissions.
Sometimes I wonder whether Anthony Watts is trying to show how wrong he is about global warming.
California has been in drought for some time now, visible in California data for the Palmer Drought Severity Index, or PDSI. It’s a measure of, well, drought severity. On the PDSI scale negative numbers mean drought (i.e. unusually dry conditions) while positive numbers mean unusually wet conditions, so it’s the most extreme negative PDSI values that mark the most extreme drought. Anyway, here are 12-month moving averages of the data through April
With the death toll from a recent killer heat wave in India up over 2,500, making it India’s 2nd-deadliest heat wave on record and the world’s 7th-deadliest, I can’t help but think how much more common this is becoming. Russia 2010 with over 55,000 casualties, the 2003 European heat wave killing over 70,000, are still fresh in our memories. One wonders how many more such “memories” lie ahead.
When it comes to temperature at Earth’s surface, with 2014 the hottest year on record and 2015 on pace to exceed even that, things are getting hot for those who deny that global warming is a danger to us all.
In their scramble to find something that looks like global warming has somehow “paused,” they seem to have settled on one particular data set with which, if you wait until just the right moment to start looking, it looks like they want it to look.