A Bit of (Climate) Perspective

Weather is not climate. Most humans conflate the two, such that they consider the fact that it is snowing outside as irrefutable evidence that global warming cannot be possible. Yet it is possible for me to acknowledge that today on March 1,  the Ohio valley today had a storm system pass through that was reminiscent of late April. I’m sitting in my den and see that the daffodils that I’ve worked to cultivate over the decades are at peak bloom – on March 1!  We had crocus bloom in January. Now, I am the first to acknowledge that, just like the presence of snow in winter does not refute global warming, an abnormally warm winter with early blooms does not prove global warming’s existence.

What has become evident is that, regardless of source, the climate is warming on this planet. The evidence of this warming is more pronounced in the polar regions, where we may hear in a few weeks that the Iditarod is once again suffering from a lack of snow. I am totally upset when I see a show like CNBC decry the notion that CO2 emissions cannot cause warming of the planet. I see talking heads nodding sagely in agreement that increased CO2 levels will be a huge advantage as it will foster luxurious plant growth to help to feed the increasing population. I wish to provide some guidance in this post as to why these popular beliefs are not correct.

Part of my college education involved a study of thermodynamics. You know, one of those classes that require the use of advanced calculus to be able to understand and use the principles of thermodynamics. One of those courses that only those of us elites think are important. Well, one concept that is taught in thermodynamics is that of  black body radiation. It turns out that this is the key concept in understanding why CO2 and other greenhouse gases are so potent in adjusting the earth’s thermostatic control.

Now, I think of black body radiation around my house, as our black cats absorb the heat emanating from the furnace vent, then re-radiate it back over time. Well, the concept also works with the atmosphere as well. The earth’s surface absorbs heat from the sun during the daylight cycle. Once the sun is below the horizon, radiation of the absorbed heat begins. Now, once heat is emitted in the infra-red portion of the electromagnetic spectrum, it will leave the earth and its atmosphere – unless it is intercepted. Nitrogen and oxygen do not absorb energy in the infra-red spectrum, so that part of the atmosphere is transparent to the infra-red, and the heat leaves the earth.

But trace gases in the atmosphere can intercept the infra-red radiation. And once they absorb it, they can release it back as they cool. Now, when they release it back, they do it omni-directionally. Some continues on to space, and some returns back to the surface of the earth. Water vapor is one example of a trace gas that serves to return heat energy to the earth. And, so is carbon dioxide, and methane, and many other compounds that have been created through organic chemistry and disseminated throughout society. The increasing levels of these trace gases does indeed have a significant effect on the ability of heat to leave earth’s atmosphere, thereby inducing a rise in the thermostat of earth.

Many who deny anthropogenic climate change throw out other factors that can affect climate as well. It is true that we on this planet are inextricably bound with the solar input, and if the sun changes the amount of energy we receive, then it will affect global climate. The effect of the sun is greater than any amount of climate forcing that we humans can cause. Likewise, volcanic eruptions can result in significant global cooling, as the particulates from the eruption and from sulfates forming from the eruption shield earth’s surface from the sun’s energy. I understand and accept that those factors can cause effects many times greater in size than the effects from the gases that man has emitted.

Still, the thermodynamics of black body radiation cannot be denied. And it is true that, in the absence of other external factors, trace gases that absorb and re-emit infrared radiation will increase the black body temperature of earth. This is the basis for taking action to reduce global greenhouse gas emissions in order to minimize the total amount of temperature change that we face.

One area of concern for me is that denial of human-caused climate warming leads to denial of the possibility that global warming is happening, and therefore we don’t need to mitigate the risks. I see coastal states where governors have forbidden their state employees from using any resources into planning what to do in order to mitigate sea level rises. These are states that are already facing tidal flooding at an increasing rate, and are also subject to salt water intrusion into ground waters. Even if humans are not responsible for the changes we are seeing, is it not prudent for our government to be preparing to deal with the effects that are already happening? Or will we be like ostriches that stick our heads into the tidal flats, only to be drowned by the ever-higher tidal flood?

 

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