Straight talking on that crooked consensus

crooked line

Crooked.

Lawrence Solomon: 97% cooked stats

First published in the Financial Post, Jan 3, 2011
(h/t Gary Kerkin)

How do we know there’s a scientific consensus on climate change? Pundits and the press tell us so. And how do the pundits and the press know? Until recently, they typically pointed to the number 2,500 — that’s the number of scientists associated with the United Nations Intergovernmental Panel on Climate Change. Those 2,500, the pundits and the press believed, had endorsed the IPCC position.

To their embarrassment, most of the pundits and press discovered they were mistaken — those 2,500 scientists hadn’t endorsed the IPCC’s conclusions, they had merely reviewed some part or other of the IPCC’s mammoth studies. To add to their embarrassment, many of those reviewers from within the IPCC establishment actually disagreed with the IPCC’s conclusions, sometimes vehemently. Continue Reading →

NZ vs S. Hemisphere temperatures

The “Seven-Station Series” (7SS) constituting the official New Zealand Temperature Record (NZTR) is analysed and compared with the Southern Hemisphere (SH) temperature record using an interesting new data analysis technique called Empirical Mode Decomposition (EMD).

UPDATE 1, 10 JAN 2011, 22:28 NZDT

Analysis of temperature trends usually employs extrinsic data smoothing techniques such as regression, moving average and Fourier filtering, but there is a more appropriate technique available.

Empirical mode decomposition (EMD) is an intrinsic data analysis technique now being used across a number of disciplines, including climatology. You can find out more from these two background papers: On the trend, detrending, and variability of nonlinear and nonstationary time series (Wu et al., 2007)(pdf) and Analysis of Temperature Change under Global Warming Impact using Empirical Mode Decomposition (Molla et al., 2007)(pdf). If you want to study EMD in detail, there’s a lot of help available — even a free command line utility.

EMD uses a sifting algorithm that filters the data until an overall adaptive trend (monotonic residual) is revealed. The first paper linked above shows how a decadal trend was also extracted from the global record but the 100-year 7SS time-frame used here is too short to do the same. A longer 7SS record would probably reveal an intermediate decadal trend similar to that presented plus an overall trend that cannot be extracted (by this author) from the 7SS at its current length. Continue Reading →

Tepid support from BoM

Sydney Opera House at dusk

Constrained support

The Australian Bureau of Meteorology (BoM), like the National Institute of Water and Atmospheric Research (NIWA) in New Zealand, is an advisory group of Government scientists responsible for the compilation and maintenance of official temperature records.

After NIWA scientists rewrote the official NZ temperature record — the Seven-Station Series — during 2010, their ‘Review Report’ included a letter of support from the BoM. This was seen as necessary, as NIWA’s credibility had been somewhat strained by its lengthy (and ultimately futile) defence of the old record.

Some are critical of the selection of the Bureau to review work by NIWA, as both groups have been widely criticised (especially in the blogosphere) for applying the same biases and questionable adjustment methods. See, for example, Australian Temperatures in cities adjusted up by 70%!? at Jo Nova’s blog.

As climate archivists, both agencies are extensively engaged in the work of the IPCC; and both are firmly of the school of thought led by Professor Phil Jones, head of the Climatic Research Unit at the University of East Anglia (UEA).

The NZ Climate Science Coalition wrote to Science Minister Wayne Mapp, suggesting the appointment of two genuinely independent reviewers, and putting forward names of highly regarded scientists and statisticians. Continue Reading →