Perhaps the most sobering aspect of global warming is that we might be nearing a tipping point of monstrous importance. This point will be reached when the emissions of the Earth’s vast quantities of stored carbon begin to add significantly to our atmospheric levels of carbon dioxide and methane. To appreciate what I am referring to, let’s start with the figure shown below.
This figure shows the change in average ocean bottom temperature of the Earth over the last 65 million years (that is, since the extinction of the dinosaurs). This figure shows that our average temperature has been decreasing over the last 50 million years. Over that long period, a vast amount of atmospheric carbon dioxide was converted to vegetation via photosynthesis. Following the death and oxidation of that vegetation, much of its carbon was converted back to atmospheric CO2. A large fraction of that organic matter was not completely oxidized back to atmospheric CO2, however, and instead was trapped on the Earth in the form of various organic compounds. The most abundant of these is methane (CH4) which is formed by the complete anaerobic reduction of all organic matter under oxygen-deficient environments such as those that exists in soils and ocean bottoms.
Over the last 50 million years, the products of these anaerobic processes have continuously accumulated in specific locations as the Earth’s temperature decreased. In particular, massive quantities of methane clathrates have been deposited below the ocean floors of coastal regions throughout the world. Similarly, a lot of volatile organic matter has accumulated in the permafrost of all high latitude regions of the Earth.
Thus, the Earth today can be legitimately said to be a loaded “powder keg” ready to “go off”. All that is needed to trigger this virtual explosion is an increase the Earth’s temperature to a point the initiates that process. Once initiated, the increased atmospheric level of the powerful greenhouse gas CH4 will further increase temperature causing yet more CH4 to be released. An irreversible run-away process will then occur, releasing more and more CH4 until the natural deposits have been depleted. The total amount of greenhouse-gas warming thereby caused would far exceed that which we would expect to occur by the combustion of all of the fossil fuels on Earth. To put it frankly, the “game” would indeed then be over for our species on this much warmer planet. I realize that to the lay public, talk such as this sounds like “science fiction”. Unfortunately, this is the prediction of well-documented and strait-forward science.
Nevertheless, let’s ask again, is this horrendous outcome really possible or even likely? Yes, absolutely it is – if we continue our emissions of CO2 into the atmosphere. Business-as-Usual projections of the Earth temperature all point to non-stop temperature increases throughout this and the next century. The only variable mankind has any control over is its cumulate total emissions of CO2 and CH4 (which is oxidized to CO2 within 10 years of its emission) over time and there are currently no indications that these emissions will be leveled, much less brought to zero as is required. Global emissions of CO2 by fossil fuel combustion are still increasing, not decreasing or even leveling. In short, there is no reason to expect that the “triggering point” of “Powerkeg Earth” will not be reached within this or the next century.
In addition, we also know that carbon explosions of this type have occurred before when the Earth’s temperature was increasing. One of these occurred about 56 million years ago and is clearly seen as a “momentary” event of about 150,000 years duration in the figure above. The temperature rise that caused this carbon explosion is thought to been the motions of continental shelves and a resulting increase in volcanism and CO2 emissions. This thoroughly studied event is called the Paleocene -Eocene Thermal Maximum (PETM). This event is very similar to that which is now poised to occur due to mankind’s combustion of fossil fuels.
Since the science behind all of this is now so well established, the only alternative left for those who can’t accept it will be to deny the science and the field of science itself. Many and perhaps most will probably do exactly that. After all, do you think the unfortunate souls that were herded into the barracks of Auschwitz told each other that they and their children would soon be headed for the gas chambers? No they did not. Their favored view was to promote the idea that the work they did in those “work camps” was too important to the German war effort as to allow their extermination. For that very same, understandable reason, the general public and the officials we tend to elect will continue, as they have to date, to ignore the implications of the business-as-usual “plan” we are presently on. It is profoundly unfortunate that a portion of the human anatomy has not yet evolved sufficiently as to enable our species to face its greatest problem.
Stated instead in religions terms, we have not made optimal use of the greatest gift God has given us – our brains. Instead, we are presently suffering from what I call the “hubris of mankind”. We tend to think “we have been here a long time” and have “faced some tough times before” and “can handle just about anything that comes our way” and “will surely solve this problem also when the clear need arises”. All of this is unadulterated BS, of course. On the geological time scale, “we just got here” and have not even paid due attention to what our scientists have learned in the last couple decades.