As an outsider to the global warming debate, as nearly all of us are, it is hard to evaluate the claims and counter-claims. Some say there is a consensus. Is that true, and if so, is the consensus right or merely the product of group-think?
Last year, I was able to have a conversation with a mainstream (i.e., not a “skeptic”) climate scientist and got his account of the state of play in the field. He said that the evidence is very good that the climate is warming and that carbon dioxide levels are increasing, and that it seems very likely that humans are responsible. In regard to projections of future climate, he said that the direct effect of increased carbon dioxide is not very large, and estimating the indirect effects depends on computer models.
Unfortunately, (this is my opinion now, not his), we cannot rely on the computer models, because they do not make predictions that we can test, so we really don’t have any good science for predicting the future. Nevertheless, we have a pretty good idea about the past.
That’s what I thought, but my confidence was shaken two months ago when I read a National Review article alleging that prominent climate researchers refused to reveal their data and methodology. The allegation is serious; if true, it completely undermines their work. We don’t accept scientists’ word for their results. Even if a scientist is honest, he might make a mistake. We need to be able to verify the results. Refusing to reveal the data and methodology is like a mathematician claiming a theorem and refusing to provide the proof. Such a result is worthless.
Even worse, the article alleged that the researchers withheld their data specifically to keep it from skeptical scrutiny, saying: “Why should I make the data available to you, when your aim is to try and find something wrong with it?” The answer is: because that’s how science works.
Still, the article seemed to be based on interviews with just one side, so perhaps they weren’t a fair account of what happened. I did some googling, but I was unable to verify the claims independently. So I waited, hoping something would come out to clarify matters. And now, of course, something has.
Unless you’ve been living in a cave without internet access, or you get your news from the mainstream media, you’ve heard of the leaked emails and documents from the Hadley CRU. They show that the National Review article was absolutely accurate. The Hadley researchers were determined to withhold their data, specifically to protect it from skeptical scrutiny [1228330629, 1059664704, 1074277559, 1254345174, 1256735067]. They were even prepared to delete it, rather than release it to the wrong people [1107454306, 1212073451].
The emails also show a deliberate campaign to corrupt the peer-review system. They discussed submitted papers (which are supposed to be confidential) and how to sabotage them [1054756929, 1077829152, 1233249393]. They worked to oust editors with a skeptical bent, or who were even suspected of a skeptical bent [1051190249, 1106322460]. They spoke explicitly of “plugging the leak” at journals that sometimes published the work of skeptics . So when people speak of a consensus among peer-reviewed research, it turns out that doesn’t mean as much as you might think.
But let’s return to the withholding of data and methodology, because it turns out they had much to conceal. I’m not sure if the data was included in the leak; if so I haven’t seen an analysis of it yet. However, the code is part of the leak, and the code, frankly, is complete crap.
One file, the now infamous HARRY_READ_ME.txt, chronicles the effort of one poor programmer (Ian Harris, according to Real Climate) to maintain the code base for one of their temperature databases. It documents endless problems with the code: subscripts out of range, segmentation faults, overflow (e.g., causing a sum of squares to become negative), underflow, division by zero, silently ignoring exceptions. Pretty much a complete disaster. (UPDATE: Good link as of January 2014.)
ASIDE: The last one is so appalling it’s worth a short look. (Fuller story here.) At one point in Harry’s tale he had to deal with the code that determines whether a station contributes to a cell (whatever that means). This amounts to determining whether two points are within a certain range of each other. Rather than do the necessary geometric calculation, the code uses the graphics library instead (!):
..well that was, erhhh.. ‘interesting’. The IDL gridding program calculates whether or not a station contributes to a cell, using.. graphics. Yes, it plots the station sphere of influence then checks for the colour white in the output.
But better yet, when IDL occasionally generates a plotting error, the code simply ignores it and moves on. (You can find this in documents/cru-code/idl/pro/quick_interp_tdm2.pro).
There’s much, much, more. Near the end of Harry’s tale of horror comes this:
I am seriously close to giving up, again. The history of this is so complex that I can’t get far enough into it before by head hurts and I have to stop. Each parameter has a tortuous history of manual and semi-automated interventions that I simply cannot just go back to early versions and run the update prog. I could be throwing away all kinds of corrections – to lat/lons, to WMOs (yes!), and more.
The bottom line is that nothing their code produces can be trusted.
Some people are delighted by all this. I am not. Instead, I am furious. As a libertarian, I would like to believe that global warming is a myth, but I have thought it unlikely that an entire scientific field could be wrong. But now, who’s to say? Since it now appears that the peer-review process in climate science is corrupt, an outsider cannot begin to assess which claims are valid and which are not; we can only assess which ones are in and which are out. I feel as though I’ve been lied to. (And perhaps I have. How can I know?)
It would be exaggerating to draw from this that there is no science of climate, but not by all that much. Here’s the thing: climate change matters, if it is real that is (which I still think it probably is, retrospectively at least). It would be useful for us to know something about it.