Global Warming, Ice ages, and the like

Recently I wrote a letter to the Mensa Bulletin about the topic of Global Warming. I will not repeat that here, but rather will expand on what I said. The one hundred fifty word limit made it difficult to express what I wanted to express.

I will add a discussion of Ice Ages and their cause, because this is directly related to global warming. I will begin by relating a story.

A few years ago I visited an historic site. This was a house that had been historically significant for a period of about fifty years. During that time, the tour guide pointed out, the house had undergone major remodeling. Therefore, when the house was "restored" the restorer were faced with a problem. When would they restore the house to? That is, which set of remodelings and repaintings would they restore? Of course, they chose a year during that period, and restored it to that year as best they could.

This is analogous to the problem facing environmentalist, whether they realize it or not. The environment has been around for literally billions of years. In restoring the "environment" which year will it be restored to?

Facts:

I my observations are based on facts as I see them, and I will review some of them here.

First, I am not a climatologist, however I will note that the series "Walking with dinosaurs" points out that during much of the time dinosaurs were on the Earth there were no polar ice caps. That is, in the summer even the south pole warmed to the point that all the ice melted.

I will also note that the similar series dealing with human evolution (I have forgotten the exact title, it was something like "Walking with Cave Men") notes that when the homanids started to walk upright the Earth was completely covered with vegetation. That is, the reason humanids (prehumans) started to walk upright was that this gave them and advantage over their cousins who didn't because they could see over the grasses, and therefore could see the predators earlier. The main point I will note is that the Earth was covered by vegetation.

Ice ages come and go. There have been several period of time called ice ages in the past. Further, these have not been uniformly cold periods of time. That is, the ice ages have periods where the ice if very thick, covering most of the planet, and periods which are quite warm. At least one reference had noted that the period from today to the last ice age is less than the warmer periods that occur during the ice ages.

That is, rather than being on the edge of an ice age that ended 10,000 years ago, we may actually be in the middle of one.

Theories

I have seen several theories presented for the ice ages. For the most part, the comments I've seen are that the author of the comment didn't know why they occurred, but a few have speculated.

One I recall says that the sun, for some unknown reason, cools off on occasion. That is, the solar furnace decides to not be as hot for a few thousand years. I've never seen any suggestion as to why this would be from astronomers, but that was the theory. If this is true, then ice ages are inevitable, and there is nothing people can do about it, except prepare for the next cool down (which hopefully will not be permanent).

A second, rather interesting, theory I've seen is more catastrophic in nature. That is, ice ages are caused by a catastrophe, in particular, the polar ice caps (this theory assumes they always exist) become very heavy and unbalanced. That is, the center of gravity of the polar ice caps is a certain distance from the pole. If the ice cap becomes heavy enough, or the distance from the pole far enough, then the Earth mantel will separate from the core, and the ice capes will suddenly find themselves at the equator, and a new spot will exist for the poles. If this is accepted, then as "rulers of the planet" people should try to keep the polar ice capes balanced.

At this point I will suggest a third theory which seems more reasonable to me. That is, the Earth is "normally" quite a bit warmer than it is today, that is, to the point that there are not normally polar ice caps. During these periods there is quite a bit of carbon dioxide in the air, and the phenomenon we call "global warming" is at its extreme. This would favor the growth of plants, and a lush vegetation. That is, the warming would warm the oceans to more water would evaporate into the atmosphere, so the planet would be more moist, and the increased carbon dioxide would tend to favor the growth of plants.

Ice ages form then when the growth of plants outstrip the creation of carbon dioxide. Therefore the carbon dioxide in the atmosphere drops, so the climate favoring plants decreases as well. Plants die. Therefore, the carbon dioxide is not used up, so the global cooling is stopped. The planet will cool to whatever is required to kill enough plants to allow the generation of carbon dioxide to outstrip the usage by plants. Of course this is not instantaneous, so warming and cooling cycles occur – somewhat akin to what happens when the one displaces a weight at the end of a spring.

Right now we are at a time when the creation of carbon dioxide is outstripping what plants can use, that is, a time of global warming. A fact I did not point out above is that global warming has been going on since the last ice age (or the cool end of the cycle) 10,000 years ago, with some mini ice ages in the interim.

Why are there Ice Ages?

Consider the carbon cycle. That is, there is carbon dioxide in the air. This is used by plants to make food and other organic material. The carbon is then released into the atmosphere when the plant dies, either by it being burned in a fire, or oxidizing more slowly sitting in the oxygen atmosphere and rotting. (Some goes through a slight divergence by being eaten by animals – but the result is the same.)

This is the normal cycle for carbon. However, it can, and has, been short circuited. In times of heavy vegetation, not all the vegetation is oxidized. That is, if it is wet enough, the vegetation just grows on other vegetation forming a thick layer of carbon. When this happens coal is formed, or oil depending on the life that is building up. The important point is that the carbon is taken out of the carbon cycle above, so the carbon dioxide in the atmosphere is not being generated, and the carbon dioxide in the atmosphere decreases, so the greenhouse affect of the carbon dioxide is lessened, so the planet cools.

This is why there was no polar ice capes when the dinosaurs were on the planet. That was "normal." At that time most of the carbon currently in oil and coal was in the atmosphere warming everything. But then the coal and oil were formed, reducing the carbon dioxide in the air, and the greenhouse affect to the point the planet cooled. Hence the ice ages.

During the ice ages the plants were killed, and the ice expanded to whatever was required to increase the carbon dioxide to the point the cooling would stop. As noted above, this would result in a cycling affect because the climate, and plants, cannot react instantly to the changes temperature, nor the climate instantly to the changes in carbon dioxide.

This suggests that people can prevent another ice age, and people are currently doing precisely the right thing. Burn coal and oil to increase the carbon dioxide in the air. This will bring us back to the lush vegetation that existed prior to the last ice age. Of course the temperature will go up, and climates will be affected. If may be that species will need to evolve to accommodate the change. Perhaps genetisist can even help out, particularly with plant species that are needed for human food, etc.

I have been told (although I have not researched it) that the Mississippi river would not flow past New Orleans except for dams that keep it in its course. That is, normally rivers meander a bit, and the Mississippi at the current time would meander away from New Orleans except for human intervention. Any attempt to control global warming due to burning coal and oil is, in reality, the same sort of thing. Normally this carbon is in the atmosphere, and the planet is much warmer than it currently is. We, as a species, and as custodians of the planet, may decide that we want to keep a bit of the ice age for our comfort, which is what limiting oil use does, or we can chose to allow the planet to return to its normal state, one that has not existed for a million years. The choice is ours, and will be made for us (in favor of the latter) if we continue as we have.