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Elementary Science Education

Climate Change

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    • #8407

      Bernard Nebel

      I wish that I could go along with climate-change deniers and conclude that climate change is a hoax. Unfortunately, scientifically weighing the evidence forces the conclusion that climate warming is real; the prime cause is increasing carbon dioxide in the atmosphere, and the source of that increase is the burning of fossil fuels and other human activities. The main points of reasoning that bring me to this conclusion are the following:

      1. The temperature of a body is a balance between incoming and outgoing energy. For the Earth this is a balance between incoming solar radiation and outgoing radiation of heat (infra red radiation) to outer space. Note that temperature may be influenced by changing the flow of either the incoming or the outgoing energy.

      2. Carbon dioxide strongly absorbs infra red radiation. Therefore, increasing carbon dioxide in the atmosphere has a climate warming effect by blocking the exit of infra red (heat) radiation into outer space. It is the effect of covering yourself with an extra blanket.

      3. The atmospheric concentration of carbon dioxide has been carefully monitored over the past 60 years. See the graph at:

      (The wiggly nature of the line reflects the difference between winter/summer photosynthesis/respiration.) The graph shows a better than 30 percent increase in atmospheric carbon dioxide since 1960 — a 30 percent increase in “blankets on the bed”.

      4. This increase in carbon dioxide is directly correlated with our burning of fossil fuels (coal, oil, natural gas), for which there is ample data.

      5. We are witnessing manifold effects of a warming climate — record temperatures, droughts, increasing numbers and severity of storms, unprecedented melting of glaciers and icecaps, etc.

      With these facts, I can only conclude the climate warming is real and that our burning of fossil fuels and other activities that increase CO2 (and other greenhouse gases) are responsible. Yet, there is still a substantial number of climate-change deniers. The following are prime arguments used climate-change deniers followed by why the argument is spurious.

      1. The amount of CO2 in the atmosphere is minuscule; It can’t possibly have an effect.
      Evidence: The percentage of CO2 in the atmosphere in 1950 was 0.03%. This may seem “minuscule” but it fully supported the photosynthesis of every plant on Earth. Further, one can mathematically calculate that 0.03% is 3 x 1013 molecules of CO2 in every cubic centimeter of air. The observe increase of 30% to the current 0.04% is an addition of 1 x 1013 . An addition of 1 x 1013 molecules of CO2 to every cubic centimeter is hardly “minuscule”.

      2. Water vapor is a more potent absorber of infra red radiation than CO2. Therefore, water vapor may be responsible for the warming effect we are observing.
      Evidence: The amount of water vapor in the atmosphere is a direct and immediate response to heating of water—more heating, more water vapor. There is no way that water vapor can increase ahead of heating and be the cause of global warming.

      3. Climate has always changed. Get used to it.
      Evidence: To be sure, analysis of ice cores and other studies reveal that
      climate has changed over the course of the last close to million years. And, these same studies reveal that atmospheric CO2 also changed synchronously with the climate. (See climate/historic CO2 graphs:
      In short, these studies suggest that CO2, far from being incidental, has been the driving force behind historic climate changes.

      Please post additions (pro or con) to this discussion. Also post questions.







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