We Live in a Greenhouse by Bruce Grant
In the April OSCAR, I contributed a story about the biodome at the Brewer Park Community Garden. In the story, “The temperature outside was around freezing and snow covered the ground, but inside it was comfortable for working.” The greenhouse effect was at work. Yet, a recent story in the news reported that
30% of Canadians still don’t believe in a man-made greenhouse effect as the cause of global warming. I
think if we’re not settling this question it’s because we’re arguing in the wrong way.
We are presenting an inductive argument that we can’t prove; we should be using the deductive argument that we can prove. Let’s examine the difference.
Isaac Newton sat under an apple tree and observed the fall of an apple. I would have just eaten the apple, but Newton, the great intellectual that he was, wanted to understand why the apple falls. If the apple is drawn to the earth, isn’t the earth equally attracted to the apple? Why does the moon orbit around the earth? Why doesn’t it fall like the apple? Or why doesn’t it fly away like a stone from a sling?
From simple observations of well-known phenomena, Newton induced his laws of motion and his law of gravity, published in 1687. Induction is the process of expanding particular observations into general rules. In our times, we still apply Newton’s theories to deduce what will be the trajectory of a missile or the orbit of a satellite or a comet. Deduction is the process of using the general rules to anticipate what will happen in a particular case.
We are all but unanimous that the earth is warming; the argument is only about the cause of it. The earth’s climate is a very complex and ever-changing thing and it was so even before people started messing with it. How can you prove to skeptics that global warming in our time is caused by man-made greenhouse gases? We waste our time trying to induce the theory behind global warming. It has already been done.
John Tyndall, an experimental physicist in 1859 was interested in questions about global climate and he performed some experiments. The assumption in those days was that all gases are equally transparent to light. He tested nitrogen, oxygen and hydrogen, the main atmospheric gases, and found that the assumption was correct.
Then he tested coal gas, because it was close at hand as the source of light and heat in his laboratory. He discovered that for heat rays, the coal gas was as opaque as a plank of wood. He went on to test carbon dioxide and other gases that were all larger molecules than the main atmospheric gases. Same results. Those larger molecules are not transparent to heat rays, what we now call infra-red light.
Since that long-ago time, the experiments have been repeated and expanded and the results have been quantified to the point where Tyndall’s theory is proven no less than Newton’s theory of gravitation. Simply put, the larger molecules of gas are opaque to heat rays. So, heat comes to us as visible light from the sun which heats the ground, but the resulting infra-red heat rays are partially blocked from being reflected back out to space. Let’s apply the theory to answer this scientific question: Can we deduce from the theory what will happen if we increase the amount of atmospheric carbon dioxide? Yes, we can. Climate scientists, starting with Tyndall, have given us their predictions and observations have shown that they were correct.
Now, the onus must be upon the climate change deniers to deal with this little problem. 1: The climate theory, based on experiments showed that increasing greenhouse gases such as carbon dioxide and methane would cause global warming. 2: Measurements of these gases show that they have increased in our atmosphere by about 40% since the beginning of the industrial revolution. 3: Observations show clearly that global warming is happening. 4: Show us your evidence now that there is not a connection between 1, 2 and 3.
This is a guest post by Bruce Grant, retired Engineer and Layabout who is a resident of Old Ottawa South.
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