UPDATE: Turns out that Beenstock and Reingewertz Beenstock et al were clueless about the data they used.
In particular, point out that the greenhouse gas
concentrations they used was not a single series but changes from ice cores in 1960 to atmospheric
grab samples. This throws B&Rs analysis into the trash can. See here for details
UPDATE: Could somebunny point Eli to a consistent set of forcings in numerical format going back to the year dot.
UPDATE: Many thanks for the pointers (see comments)
UPDATE: Take a look at Nick Stokes on this
So the new best thing in the denialsphere is a paper by Michael Beenstock and Yaniv Reingewertz from the Department of Economics of the The Hebrew University where they pull a Wegman, analyzing climate data without knowing anything about the science. Now this is par for the course in economics where there are no constraints, but it ain't so cool when you deal with physical reality. Anyhow, the rubber hits the road very quickly when they say that
The method of co-integration is designed to test hypotheses with time series data that are non-stationary to the same order, and to avoid the pitfall of spurious regression. The order of non-stationarity refers to the number of times a variable must be differenced (d) to render it stationary, in which case the variable is integrated of order, d, or I(d). We confirm previous findings, that the radiative forcings of greenhouse gases (C02, CH4 and N2O) are stationary in second differences (i.e. I(2)) while global temperature and solar irradiance are stationary in first differences (i.e. I(1)).Straightforwardly this is a claim that forcing has been increasing as a second order function, while temperature has only been increasing linearly. Given the noise in the temperature record, that is a reach as an absolute, but Eli is a nice Rabett. Still, as one of the mice said, whoa. The best estimates of the radiative forcing is the NOAA Annual Greenhouse Gas Index, which was first described in a paper by Hofmann, et al. and considers all forcings since 1979. Why 1979? Well that's when they established the NOAA Earth System Research Laboratory global cooperative air sampling network. It's also the year when Eli got a tenure track job. Makes sense.
If you look at the CO2 forcing above it looks pretty linear, but how about the total radiative forcing, because, our new hero's are claiming that
.......greenhouse gas forcing, global temperature and solar irradiance are not polynomially cointegrated and AGW is refuted. Although we reject AGW, we find that greenhouse gas forcings have a temporary effect on global temperature. Because the greenhouse effect is temporary rather than permanent, predicitons of significant global warming in the 21st century by IPCC are not supported by the data.Hmm, that looks pretty linear too (the color you can't see in the legend is for CH4). So we have the result that the radiative forcing since 1979, has been linear. What about before 1979? Well, let's go to the IPCC WGI. Calculation of radiative forcing requires calculations, that means models. The figure below is from Nozawa et al., 2005; and Takemura et al., 2005. Different GCMs, get different values, but the general trends are as shown. Even if you simply plug into simple algebraic equations to calculate the radiative forcings, those equations came from GCMs, so in a real sense Beenstock and Reingewertz are unwittingly engaging in a circle jerk, but let the magnomious Rabett Labs skip over this,
The bunnies tossed back a few beers, took out the ruler and said, hey, that total forcing looks a lot more like two straight lines with a hinge than a second order curve, and indeed, to be fair, the same thought had occurred to B&R
We also check whether rfCO2 is I(1) subject to a structural break. A break in the stochastic trend of rfCO2 might create the impression that d = 2 when in fact its true value is 1. We apply the test suggested by Clemente, Montanas and Reyes (1998) (CMR).xvi The CMR statistic (which is the ADF statistic allowing for a break) for the first difference of rfCO2 is -3.877. The break occurs in 1964, but since the critical value of the CMR statistic is -4.27 we can safely reject the hypothesis that rfCO2 is I(1) with a break in its stochastic trend.BUT, the period they looked at was 1880 - 2000. Zeroth order dicking around says that any such test between a second order dependence and two hinged lines is going to be affected strongly by the length of the record. Any bunnies wanna bet what happens if you use a longer record???
Some snark to be added later.