Jim Thompson
Jim Thompson
By Jim Thompson
HCP columnist

We started in this series two weeks ago talking about how poor a job one might have done predicting the future several hundred years ago. We brought this forward 100 years at a time and it did not get any better. I think it was very clear that looking very far into the future is fraught with lots of unknowns.

Then, last week, we talked about when conditions change, people adapt. In fact, for millennia, humankind has adapted to changing conditions. If there is anything predictable, it is that humankind is very good at adapting.

This week, I would like to finish up talking about the math involved in predicting the future. Interestingly, one must dig to find an approximation of the current global temperate (around 15.6 degrees Celsius or 60 degrees Fahrenheit). The predicted rise over the next 50 to 100 years is 1.1 to 5.4 degrees C. If you don’t understand Fahrenheit or Celsius, don’t worry – we are here to talk about the numbers, not the nomenclature (or labels, if you prefer).

But first we are going to talk about graphs and fishing poles. Most of us understand a simple graph. Often, depending on what one is measuring, there is a line, rising from a low point at the lower left-hand corner to a higher point at the upper right-hand corner of the graph. If one plotted a line from a point in the lower left-hand corner that was labeled “15.6” to a point in the upper right-hand corner labeled either “16.7” (that is, 15.6 + 1.1 ) or “21” (that is, 15.6 + 5.4), one would have graphically represented the suggested temperature rise over time, assuming we have labeled the horizontal axis in units of time and the vertical axis in units of temperature. We have two lines: One going from 15.6 to 16.7 and one going from 15.6 to 21.

OK. I hope you are with me so far. Now, let’s replace a line on the graph with a fishing pole you are holding in your hand. You’ve studied the graph and have now gone outside and are holding a fishing pole at approximately the same angle as one of the lines (you pick which one). I want you to notice that it takes a very small movement of your hand to change the height from the ground of the other end of the fishing pole by quite a distance.

So, you can say a small change at the start, makes a big change at the end, correct? Further, if you incorrectly position your hand holding the pole, the outer end can move a great distance.

If we turn this all into mathematics, we will find that a rate of change of only 1/100th of a degree per year will allow us to reach close to 16.7 degrees C in 100 years if you start at 15.6 degrees C. Likewise, we find a rate of change of 5.5/100th of a degree per year will produce a final result of approximately 21 degrees C in 100 years, again, starting at 15.6 degrees C.

Personally, I find it hard to conceptualize these kinds of measurements and rates of change. The numbers are so tiny and the surface of the earth so large (196,900,000 square miles) that it defies logic that such changes can be calculated with any level of precision. Then there is the variability introduced by the seasons. I can’t get my head around it as they say. And remember, the rate of change can possibly go down as well as up.

Let’s go back to the fishing pole as we wrap up. You have now moved to the dock, put a worm on the hook and dropped it in the water. A bluegill comes along and grabs your worm. What happened to the pole? The outer end bends downward. This represents people adapting to changing conditions and pulling the graph back in line, the point made last week.

Now, if you talk to your “friends” (including family) and express doubt about climate change or global warming, you will likely get blowback and derision over your obvious ignorance of this important subject. Take this as a warning sign. If they won’t have a reasoned, low-speaking volume equitable exchange of ideas with you, be suspicious of what they really know about the subject.

As for me, I have gotten so I don’t talk to hardly anyone about climate change, including highly educated family members. I just don’t need the angst.

Jim Thompson, formerly of Marshall, is a graduate of Hillsboro High School and the University of Cincinnati. He resides in Duluth, Ga. and is a columnist for The Highland County Press. He may be reached at jthompson@taii.com.