Tuesday, March 27, 2018

Thoughts on Climate Change

Haven't posted anything here in a long time, so please forgive the sudden intrusion. I'm here now because I've decided to use this blog as a venue for freely and fully sharing my thoughts on  the extremely controversial topic of climate change without having to worry over whether or not I'm taking up too much bandwidth on someone else's forum. For the last few years I've been posting comments from time to time on the RealClimate blog, a gathering, for the most part, of hard line "climate change" advocates, who usually find me extremely irritating, but can't resist responding to my posts nevertheless. Typically I will post some thought or quote some source that they object to; they will offer what I often consider rather lame responses, so I feel obligated to set them straight, which in turn prompts more responses from them and so it goes until everyone gets either bored or annoyed or frustrated and either I wind up backing off or my posts start getting exiled to their "Bore Hole" (don't ask).

I recently decided that there was no longer any point in continuing a prolonged debate that was going nowhere and promised to cease and desist from further responses on that topic. After making that decision, however, I noticed that one of my most persistent critics had actually posted what appeared to be a sensible response to an objection of mine, grounded in a basic principle of Occam's Razor -- specifically that certain "explanations" offered by certain climate scientists to account for evidence that, on  its face, appeared to falsify their theory, could be understood as what has been called "saving hypotheses," i.e., attempts to save a failing theory by pointing to additional factors that make everything "come out  right." As I see it, the interjection of such factors violates Occam's Razor by introducing unnecessary complications for the sole purpose of rescuing an hypothesis that would otherwise be inconsistent with the evidence.

In this instance, the evidence I was pointing to is the long period of roughly 40 years, from ca. 1940 through ca. 1979 when global temperatures apparently either declined or remained steady, while CO2 levels due to fossil fuel emissions soared. This, for me, as for so many others, is one of several instances where the evidence appears to falsify the AGW hypothesis, based as it is on the claim that global temperatures have been steadily climbing in tandem with CO2 emissions ever since the beginning of the industrial revolution.

The standard response goes something like this: in order to understand the complexities of the climate system, we need to consider ALL the various forcings that affect climate, and when we do we see that a major factor in holding down temperatures during the period in question was the emission of polluting aerosols due to the rapid and uncontrolled development of heavy industry after WWII. Since the source of these aerosols was the burning of the same fossil fuels held responsible for emitting all that CO2 in the  first place, I have always regarded that explanation with extreme skepticism. It's always looked to me like a perfect example of a "saving hypothesis," as it appears to add complications whose "necessity" is only to explain away evidence incompatible with the favored theory, making it in violation of Occam's Razor, which states, essentially, that additional "entities" should not be attached to any hypothesis unless it can be established that they are necessary for a complete understanding of the totality of the evidence.

In responding to my objection on such grounds, RealClimate regular, CCHolley offered a reasonable sounding explanation that deserves further discussion. Here is his post in its entirety:
Let’s give a simplistic example for Victor on how science actually works. 
Let’s say an early scientist is interested in applying Newton’s Laws of Motion to ballistics. He uses the law to derive a mathematical model of the predicted path of a projectile given a know initial velocity, angle of launch, and the force of gravity. The mathematical model predicts a trajectory of a parabolic arc. 
He then sets up an experiment to confirm the results of his model. Instrumentation is used to measure the initial velocity. The launch angle is set and the projectile is launched. The distance from launch to landing is carefully measured. Unfortunately the landing point is well short of that predicted. Several more launches are made to make sure the initial result was not an anomaly. All the results are similar. 
He then goes through his model and cannot find any mistakes in the derivation. Does the scientist then declare Newton’s Laws falsified? No, that would be foolish because others have confirmed the laws through other experiments. It is already considered scientific truth. Physics is physics.
So the scientist must ask himself questions. What am I missing? What are the gaps in my knowledge? Could there be other unknown forces acting on the body of which I am unaware? This opens a new line of inquiry and he eventually hypothesizes the influence of air in the form of drag on a body in motion. His evidence of such was NOT simply collected to support a pre-conceived view. It was collected to support known physical laws. 
Likewise for AGW theory. The laws of physics are the laws of physics and the laws of physics allow us to make certain predictions. When evidence surfaces that might conflict with our predictions, we don’t consider the physics falsified, we look for gaps in our knowledge and hypothesize explanations. Those hypothesis must stand on their own merits. This is NOT simply collecting evidence to support a pre-conceived view, it is attempting to explain the world based on known physical laws. We don’t just throw out physical laws because of any little bump in the road, that would be an extraordinary claim that requires extraordinary evidence. 
CO2 is a greenhouse gas that prevents heat from escaping to space. That is a scientific certainty. In a complex world, if observations seemly conflict with that scientific certainty, then looking for explanations is absolutely the right thing to do. Explanations that are supported by evidence and conform to physical laws. Aerosols like drag have an effect and cannot be ignored. We don’t throw out greenhouse gas laws just because the effect of aerosols changes the outcome. Like the Newtonian Laws, we didn’t throw them out simply because we didn’t initially understand drag.
And here is the "response" I felt compelled to offer under the circumstances:
352 CCHolley
In this post CC actually presents a very intelligent and reasonable response to some of the problems I’ve raised regarding violations of Occam’s Razor and the presentation of questionable “saving hypotheses.” Thanks for that, CC. Since I recently promised to back off on arguing any of these points, I won’t attempt a rebuttal here. Actually what is called for is not so much a rebuttal but a fresh consideration of certain very basic epistemological problems.
Because Holley's very well thought out argument deserves an equally well thought out response, based on a consideration of the epistemological issues mentioned above, I decided to move over here to this old blog I initiated several years ago to deal with certain political and economic issues, which will enable me to express my thoughts fully and freely without interference.  In the following post I will respond to Holley's objections in the  light of my understanding of what the scientific method is really all about. Please stay tuned .  .  .  (Comments are welcome at any time.)

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