Bill Meredith

"Everybody talks about the weather, but nobody does anything about it."
… Mark Twain

People who know such things tell us that children who have talent for mathematics show it early in life, and that regardless of how much talent you have, you reach your highest potential for learning and creativity in math at a fairly early age, probably by the early twenties. In my case, I missed the boat on both counts; I was born without any special talent for mathematics, and I avoided the subject in high school and college as much as possible. But apparently the gene for mathematical talent is not connected to the one for interest in numbers; in spite of my computational ineptitude, at the age of 30 I found myself in a graduate program in ecology, a field dominated by mathematical models and statistics. So it came to pass that every spare minute in the summer and fall of 1966 was devoted to analyzing the results of my experiments.

In spite of my limited background, I found statistical data to be irresistibly fascinating. The problem was that in those days calculations had to be done by hand or with a desktop calculator that sounded remarkably like a threshing machine. And the problem didn't go away when I finished graduate school; teaching, research and administrative tasks continued to flood my desk with columns of numbers to be interpreted. Eventually I was saved by Dan Brickson.

Brickson's name never became a household word, but he had an impact on my life because in 1979 he invented the computer spreadsheet. For me, that was a godsend; it enabled me to use the computer to do things my own brain was not capable of. Suddenly I found that projects like the one that took six months in 1966 could be done in a few days, and with greater accuracy. It made me more productive in the remainder of my career, and now in retirement it continues to entertain and educate.

A couple of years ago, for reasons I no longer remember, I started recording the daily temperatures from the Frederick newspaper on a spreadsheet in my computer. In one sense this is a sign that I have too much free time on my hands, for it has no useful purpose that I can think of; but it has been educational. In a smaller fraction of a second than I can imagine, the computer will draw a graph of the whole year's records. I was surprised to see from the graph that the highest average daytime temperature for this area is only 90 degrees, reached on July 20, and the average nighttime temperature reaches its low point of only 24 degrees on January 24. Between these two values the graph rises and falls in a smooth line that mathematicians call a sine wave.

The actual daily temperatures are more interesting; they rise and fall in a jagged, irregular manner that looks random at first. However, a second look shows that there is a pattern involved. Temperatures will rise above the averages for several days and then drop below average for several more. After staring at the graph for a while, I realized that this reflected the passing of warm and cold fronts, as we see on the TV weather maps every evening. It was this kind of information that led Jacob Bjerknes to discover frontal systems some 75 years ago (he was a lot smarter… he did it without a computer).

All ecologists know that the survival of any living thing does not depend on average values that have been calculated over long periods of time; the extreme temperatures reached over short periods are what are important. For example, the recent heat wave was blamed for several deaths across the U. S., but on the days that the mercury reached 100 degrees here in Emmitsburg, the average temperature was only 88. Clearly, it wasn't the average temperature that killed people.

This is one of the reasons global warming is so hard for the public to understand. Heat waves have always happened nearly every year. I can remember working in the hayfields as a boy when the temperature was recorded at 100 or above, and the temperature in my grandmother's kitchen when she was canning tomatoes on the coal stove regularly surpassed that level. It is easy to say we were tougher then, and we have grown soft by living in air-conditioned homes and workplaces, and to some extent that is true. But the fact remains that on a worldwide basis, climate is getting warmer.

The idea that carbon dioxide from the burning of fossil fuels could absorb the sun's heat and raise global temperatures was proposed by a Swedish chemist, Svante Arrhenius, around 1900. No one took it seriously at first, but by the 1950s clear evidence of a connection had been found and the Greenhouse Effect was commonly mentioned in college textbooks. I learned of it in college, and included it in the first courses I taught. From the 1960s onward, weather instruments on satellites made it possible to measure solar energy, atmospheric gases and worldwide temperatures more accurately; and the more accurate the measurements were, the clearer the connection became. The last doubters in the scientific community had conceded defeat by about 10 years ago; scientific opinion now is virtually unanimous that global warming is real, and that human activities are responsible for it. Finally we have actually done something about the weather, and that old cynic, Mark Twain, would not have been surprised to learn that what we did was to make it worse.

The average world temperature has increased only about 1½ degrees in the last 150 years, and that doesn't sound too serious; but as shown above, averages are not what count in ecology. Ice melts when it gets above 32 degrees, and each year there are more days when it gets that warm. Satellite photographs show that polar icecaps are shrinking, and instruments all over the world show that sea levels are rising and ocean currents are shifting. The evidence is unequivocal, and no informed, reasonable person can doubt it any longer. The trouble is that national policy is not always made by informed, reasonable people.

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