The Baby Boomer generation I was born into has enjoyed a very long period of relative ease and comfort made possible by the previous generation, which faced far greater hardships and endured far greater sacrifices (see The Greatest Generation by Tom Brokaw). After enjoying these opportunities and privileges since the 1950s, it is now appropriate that our generation takes its turn in addressing a life-threatening problem that has been largely of our making. The problem I am referring to is anthropogenic global warming (AGW). If this one is not solved, all of the other endeavors of mankind and future generations will be of little long-term consequence. If you think this is an exaggeration, please read on.
The basic science behind AGW is not rocket science and can be easily understood. The essence of it is as follows. The Earth contains two distinctively different forms of carbon. One of these we will call “geological carbon” (GC) here and includes “inert” substances such as the fossil fuels (coal, oil, and natural gas) and inorganic compounds such a calcium carbonate (limestone). These forms of carbon stay put in or on the Earth essentially forever if they are left undisturbed. The other basic type of carbon we will call “biological carbon” (BC) and consists of all living plant and animal materials as well as the CO2 in our atmosphere and the CO2 which dissolves in our oceans, lakes and streams. The BC forms of carbon are “active” and continuously cycle through the atmosphere, oceans, plants and animals.
The present AGW problem has been caused by the exceedingly rapid rate with which man has been converting GC to BC by the combustion of fossil fuels. While the plants might like the EXTRA CO2 we have been thereby adding to the BC cycle, both the atmosphere and the oceans definitely do not. In the atmosphere, this EXTRA CO2 increases the amount of infrared radiation (heat) that is absorbed as the Earth attempts to cool itself via its emission of infrared radiation. Therefore, just as you get warmer when you put on a heavier coat, the Earth gets warmer as more BC and atmospheric CO2 are made by the combustion of fossil fuels. In the oceans, the extra dissolved CO2 is converted to carbonic acid (CO2 + H2O = H2CO3), which makes the oceans more acidic, thereby perturbing its ecosystems.
Now consider the alarming rate with which man is converting GC to BC. We began doing this on a significantly large scale in about 1850. We now estimate that we could use up the Earth’s known reserves of oil in several decades and its known reserves of coal in about two centuries. That would mean that man could accomplish this massive conversion of GC to BC in approximately three centuries, which is to say “instantly” if viewed on the geologic time scale.
Now consider the rate with which this EXCESS CO2 will be removed from the BC cycle and returned to the inert forms of GC. First, it takes at least several million years to naturally convert plant material to the fossil fuels and, therefore, we can ignore that process. The other means of BC to GC conversion is called the “weathering” of CO2 by which, for example, the CO2 dissolved in rain drops or in the oceans comes in contact with rocks that have some calcium oxide (CaO) on it. A very small portion of that dissolved CO2 will then be converted to limestone (CaCO3). Unfortunately this process is also not fast and has a significant effect only over a time scale of several centuries to a few millennia.
Therefore, the concentration of CO2 in the Earth’s atmosphere continues to rise as GC is converted into BC. Today, the atmospheric CO2 level is 33 percent higher than it has ever been in at least 750,000 years and is increasing at a rate of 0.6 percent per year. As this rate is further increased by the rapid economic development of other countries (especially China and India), we can expect to see a 50 percent increase in the pre-Industrial Age level of CO2 by the year 2025 or sooner. Most models of the Earth’s atmosphere indicate that the probability of having reached a “game over” condition for future human beings will then be very high. Because there is a time lag of about 20 years between the causes and full effects of the CO2 level we accumulate up to any point in time, we Baby Boomers might still enjoy relatively livable conditions by the year 2025 – so once again our own generation might luck out. However, the second halves of my two grandchildren’s lives (both are presently one year old) would be exceedingly problematic, to say the least. We simply cannot let this scenario to play out and our only chance of preventing it requires that we all stop denying this problem, immediately begin to forcefully address it, and continuously intensify these efforts throughout the current decade.
Eric Grimsrud is a recently retired atmospheric scientist and chemistry professor now living near Kalispell. His current activities are described on his Web site, ericgrimsrud.com.