The Blackboard

It’s September 29, and I’m finally reporting the test of the hypothesis that the global means surface temperatures are rising at a rate of 2C/century, ( which is ‘purt dang close to the trend represented by the average of models in the IPCC AR4: That is to say, it represents a central tendency for the [...]

Once again, I am nattering on about volcanoes and GMST (global mean surface temperature).
Yes, volcano eruptions affect GMST. Does anyone really doubt this anymore? Though no one doubts volcano eruptions affect GMST, it appears some wish to estimate the variability of GMST (weather noise) since 2001 as if a volcano [...]

Climate blog-viating being what it is, readers interested in whether the current flat trend in data is consistent with 2C/century are reading terms like “ARMA(1,1)” ; those who have been reading my blog are aware that I have extended my hypothesis tests to include results we obtain if we use a statistical model called [...]

I understand some anonymous commenters at other blogs are under the impression the graph below, created by JohnV, and I discussed here long ago, proves that the recent 0 C/century (or less by some reporting agencies) 92 month trend is not inconsistent with a mean trend of 2C/century:

See those big temperature swings?
Those who [...]

Recently, Tamino described statistical model for “weather noise” using an ARMA (1,1) model. He computed his ARMA(1,1) “weather noise” using GISS observations since 1975. I think this choice is inappropriate because the choice of statistical model, and analysis period fail to account for an important observation about the variability of observed “weather”.
That [...]

I was writing a post and explaining that I’d defer running tests until Hadley posted the GMST for August. Then… I looked and voila.

July 2008: 0.412
August 2008: 0.387

I’ll still post “the math” I’m writing up first, and then the actual hypothesis test. But. . .
HadCrut3

Whenever I compare IPCC projections for global mean surface temperature (GMST) to observations, someone suggests I do the comparison a different way. Today, I’ll do the comparison yet another way!
Here’s today’s method
I will:

Plot the the average GMST from 38 model runs from the AR4 with each run “rebaselined” to the average temperature from [...]

One of the on going blog-disputes related to testing the IPCC AR4 projections of the Global Mean Surface Temperature (GMST) is whether one should the variability of 8 year trends for earth weather based on observation of the earth’s weather or based on the variability of model trends.
Of course, if the statistical properties “model weather [...]

This falls in the category of odd things found while trying to answer a few questions I was asking myself. One of the questions I’ve always wondered about is: “Do the measurement errors in the global mean surface temperature look like “white noise’?” That is, to say, is the correlation between a [...]