Watts Up With That?

For some time I’ve been critical (and will likely remain so) of the data preparation techniques associated with NASA GISS global temperature data set. The adjustments, the errors, the train wreck FORTRAN code used to collate it, and the interpolation of data in the polar regions where no weather stations exists, have given me such lack of confidence in the data, that I’ve begun to treat it as an outlier. 

Lucia however makes a compelling argument for not discarding it as such, but to treat it as part of a group data set. She also makes some compelling logical tests that give an insight into the entire collection of datasets. As a result, I’m going to temper my view of the GISS data a bit and look at how it may be useful in the comparisons she makes.

Here is her analysis:

a guest post by Lucia Liljegren

Trends for the Global Means Surface temperature for five groups (GISS, HadCrut, NOAA/NCDC, UAH/MSU and RSS.) were calculated from Jan 2001-May 2008 using Ordinary Least Squares (OLS) using the method in Lee & Lund. to compute error bars, and Cochrane-Orcutt and compared to the IPCC AR4’s projected central tendency of 2C/century for the trend during the first few decades of this century.

The following results for mean trends and 95% confidence intervals were obtained:

1. Ordinary Least Squares average of data sets: The temperature trend is -0.7 C/century ± 2.3C/century. This is inconsistent IPCC AR4 projection of 2C/century to a confidence of 95% and is considered falsified based on this specific test.
2. Cochrane Orcutt, average of data sets: The temperature trend is -1.4 C/century ± 2.0 C/century. This is inconsistent with the IPCC AR4 projection of 2 C/century to a confidence of 95% and is considered falsified based on this specific test for an AR(1) process.
3. OLS, individual data sets: All except GISS Land/Ocean result in negative trends. The maximum and minimum trends reported were 0.007 C/century and -1.28 C/century for GISS Land/Ocean and UAH MSU respectively. Based on this test, The IPCC AR4 2C/century projection is rejected to a confidence of 95% when compared to HadCrut, NOAA and RSS MSU data. It is not rejected based on comparison to GISS and UAH MSU.
4. Cochrane-Orcutt, individual data sets: All individual data sets result in negative trends. The IPCC AR4 2C/century is falsified by each set individually.
5. The null hypothesis of 0C/century cannot yet be excluded based on data collected since 2001. This, does not mean warming has stopped. It only means that the uncertainty in the trend is too large to exclude 0C/century based on data since 2001. Bar and Whiskers charts showing the range of trend falling inside the ±95% uncertainty intervals using selected start dates are discussed in Trends in Global Mean Surface Temperature: Bars and Whiskers Through May.

The OLS trends for the mean, and C-O trends for individual groups are compared to data in the figure immediately below:

Click for larger.
Figure 1: The IPCC projected trend is illustrated in brown. The Cochrane – Orcutt trend for the average of all five data sets is illustrated in orange; ±95% confidence intervals illustrated in hazy orange. The OLS trend for the average of all five data sets is illustrated in lavender, with ±95% uncertainty bounds in hazy lavender. Individual data sets were fit using Cochrane-Orcutt, and shown.

Discussion of Figure 1 Read the rest of this entry »

Here is an interesting note from grrlscientist at scienceblogs:

“In response to what appears to be a growing problem, a group of people at the Institute of Medical Science at University of Toronto in Canada wrote a scientist’s version of the Hippocratic oath. This oath (below) was recited by all graduate students in the biological sciences at the beginning of the 2007-2008 academic year. “

I promise never to allow financial gain, competitiveness or ambition cloud my judgment in the conduct of ethical research and scholarship. I will pursue knowledge and create knowledge for the greater good, but never to the detriment of colleagues, supervisors, research subjects or the international community of scholars of which I am now a member.

Given the politicization of science, such as we’ve witnessed recently from Jim Hansen’s conduct in calling for trials, perhaps making this a requirement for all graduating science majors, plus a requirement for membership to professional organizations such as AMS, AAAS, etc might be a good idea.