Time to deal with the big question of the day, is it getting hotter? I’m not a scientist, and I don’t follow this question in all of its minutiae, but I have tracked it over the last fifteen years, and I am peripherally involved by virtue of some of my professional work. The other day, I attended a meeting about global warming and projected sea level rise as part of a municipal planning effort to determine what should be done to protect critical infrastructure from flooding, particularly the sewage collection and treatment system. At the start of the meeting, a professor reviewed some of the data:
Yes, well, it seems to be warming up, doesn’t it? Permafrost is melting in Alaska, polar ice caps are getting smaller, etc. Something is happening – is it a long-term trend? At one point in the meeting, a colleague, perhaps sensing skepticism on my part, leaned over and said, “Just because at this moment in time you may not be able to determine from the data that there is a long-term warming trend doesn’t mean you shouldn’t do anything.” As a policy position, this is certainly true – you can’t wait for certainty when you have to safeguard the sanitary sewage system of a huge metropolis, but as an intellectual question, “What is going on?” you certainly should withhold judgment. I had the creepy feeling that these scientists ‘know’ that warming from human activity is happening, and that this colors their view of the data.
Remember the Dustbowl of the 30s? For generations, Americans moved west, created farms on the plains, and sowed wheat. The climate favored them with sufficient rain to do so until the twin scourges of the Depression and the dustbowl hit. In fact, the weather had been in an anomalously wet period, and it simply reverted to its established pattern of more sparse rainfall – the ‘drought’ was a result of bad land use by humans. As the author of Soil and Civilization put it, that soil should never have felt the plow. When it did, and it got dry, it blew away. [Now, farmers make up for the lack of rain by pumping from the groundwater with center-pivot irrigation, which is what makes those lovely circles you see on the ground when you fly over the mid-west. Eventually, the water will be exhausted or too pricey to pump, and we’ll have another ‘drought.’] How is one to know if one is in the middle of a temporary trend?
The scientists showed a graph of mean global temperature, rising…sort of steadily from 1860. Unfortunately, this isn’t as clear as the little graph appears because mean global temperature is calculated from stations all over the world, but not evenly distributed. And in the 1800s, there were relatively few stations…and where were they? And stations in cities tend to report higher temperatures than surrounding areas – the “heat island effect.” So, as they remarked, the earlier data has much uncertainty. So, again, how do you know if the trend is long-term or a mere blip in the record?
It all comes down to the models that scientists have created of the global weather system. If you can create a computer simulation of the weather system, and if you begin your simulation in the year 1850, and if the results match the graph I mentioned above, then you have a good model, and you feel comfortable using it to predict the future, right? [This is known as hindcasting (calibration) and forecasting.] But what if there are problems with the data that you are trying to match. And what if there are elements in the weather system of which you are unaware which you don’t understand well that might bring different effects from the causes you input to your model. [Candide said, “Il n’ya pas d’effet sans cause.”] How do you know what you don’t know? The modelers put their faith in calibration – if it mimics past behavior, it’s good. Then there are the questions of how well it has to match past data for you to have confidence, etc.
This is a devilishly complicated business. There are entire books written just on the questions of assessing the data related to one element of this question, e.g., the nature of the global mean temperature record. As an engineer who is well acquainted with computer modeling, I have to say that the tenor of the remarks I hear in meetings such as these is almost always rather cavalier, while my colleagues, who are modelers, though of water, not atmosphere, cluck a bit and shake their heads: “Well, maybe…we can’t even get the East River quite right – they’re doing the global climate!?”
Sometimes I dip into the literature with my big toe: What I find there is a lot of honest discussion of all these issues. It’s in the editorials that people put on their spin. Part of this is philosophical differences…
So What of It – What is to be Done?
I can think of so many reasons why we should burn less fossil fuel: political reasons, public health reasons, environmental reasons…global warming isn’t one of them. I can’t even see that as a practical motivator; human society just can’t respond to such amorphous threats; the Indians and the Chinese are not going to forgo their automobiles just because of these warnings. Sure, warming may bring disaster for some…island dwellers…but the rest of us will get on. Nobody misses what they never had. Europeans today don’t wail about the fact that 80% of the continent used to be deep forest and now it’s gone: Future generations may not care that it’s a bit warmer. Humans are as hardy as cockroaches – we’ll survive it, though it might very well be preferable to avoid it. Even if we were to implement the Kyoto protocols, it would only minimally slow the rate of warming, if that.
So, use less energy – conserve, be efficient, develop new technology: Achieve energy independence and leave the Sultans of Crude to thrash about in their bizarre medieval cum modern world: Improve public health by reducing smog and particulate emissions; cut acid rain and improve environmental quality: develop mass transit, fight sprawl, preserve natural habitat, cultivate an environmental ethic of stewardship – all great things! Let’s do it. At least if anthropogenic warming does come about, we’ll have a more pleasant world in which to experience it!