Thursday, December 10, 2009

Another Take on "ClimateGate"

A main reason that I am a proponent of bicycle commuting is my belief that bicycles can be a key part of reducing pollution that comes from automobiles. Transportation emissions account for a significant percentage of global emission of pollutants. The complex brew spewing from tailpipes includes hydrocarbons, nitrogen oxides, particulates, carbon monoxide, and carbon dioxide. This last molecule has been implicated as the cause of anthropogenic global climate change more commonly known as global warming. Or has it? Some people have seized on the recent illegal release of emails between climate researchers, claiming that the emails demonstrate a conspiracy in which the evidence for global warming has been fabricated. Which brings us to the point of this post. I am not an expert in climate change. I haven't downloaded and plowed through all 120 MB of the released emails. I can however provide the viewpoint of working scientist, and that is the following: I am mostly unconcerned about ClimateGate. There are several reasons for this. Although it is true that some of us are irrevocably scarred from the memory of that pretty girl in 5th grade homeroom who laughed at me when asked to the dance and that some of those people will go on to build orbiting instruments of Armageddon, most of us are good eggheads. But there are perhaps more compelling reasons for my attitude. Some of what I have seen in the popular press has been extremely misleading. Important points have been missed.

1) Claims of data manipulation: I hear ClimateGate commentators derisively referring to data manipulation as if that by itself is somehow wrong. The fact is that virtually all raw data needs to be manipulated in order to make sense of it. A slew of software exists for just this purpose. Data are smoothed, differentiated, filtered, and thoroughly mathematically churned. Data are discarded because of perfectly legitimate statistical reasons or because you realize that your fluximizer was not properly thermalated for the first 10 minutes of your experiment. And so on.

2) Citations of researchers using "tricks" to "hide" results: As has already been pointed out, it is not uncommon in Geekville to refer to a clever way of solving a problem as a "trick". Similarly, the word "hide" is frequently used in the context of displaying multiple items that overlap. Igor Pro is a common data manipulation software package. A search for the word "hide" in the Igor manual shows that the word turns up more than 150 times. One "trick" that I have used to "hide" something (an axis) in an Igor graph is to change its color to that of the graph background, thereby rendering it invisible. Nothing nefarious there, I assure you.

3) Scientists are people. People are self-serving. Therefore, scientists are self-serving: One of the easiest ways to make a name for yourself in science is to overturn an existing paradigm. The contrario spirit runs deep in our blood and has been an essential part of the scientific mindset since well before Galileo's time. Just ask my wife. To a young climatologist early in his or her career and with not a lot to lose, the juiciest of all the low hanging fruit would be to show that humans are not responsible for global warming. But this has not yet happened.

It may yet turn out that some climatologists have faked or improperly treated their results. But there is no conspiracy. The "climate-change-denialist fringe" referred to in the previous link imperil us all.

No comments:

Post a Comment