During the time I taught the class it consisted of anywhere from 50 to 120 students. The students ranged from experienced engineers that would have liked me to derive the formulas to undergraduates and the general public, some of whom had trouble plugging numbers into a formula to come up with the answer. It is difficult to teach a class that large and with that variation of student experience and interest. In 1978, I was transferred to Arizona by the U.S. Public Health Service for a two year stint and Will Nelson took over teaching the arctic engineering classes in Anchorage.
Over the years, I've heard some criticsm about how E.B. (and later I) taught the course. We used a lot of examples ("war stories") and not much theory. The objective of 603 was to create interest and provide a very basic description of cold regions engineering and construction. It was intended to alert a "down south engineer" when he was in "over his head" and should get help or should take additional courses. No matter the experience level of the student, they'll remember the how-to and how-not-to examples long after they have forgotten the formulas. You can't make a cold regions engineer out of a down-south engineer in one clase, no matter how it is taught. Arctic Engineering 603 and 604, as developed by E.B., did a good job of fulfilling this basic need.
As you all know, the earth is essentially a greenhouse because of our atmosphere. If not, the earth's surface ad weather would be like the moon's: -170C at night and +100C during the day. The major atmosphere gases that protect us from these extreme are as follows:
An example, cows in the United States alon produce 45,000,000 tons of hydrocarbons and methane each year. They belch this up when they regurgitate material from their first stomach to chew it for the second stomach. I understand someone in England has a research project to find ways of preventing or reducing this.
The largest single source of greenhouse gases may well be termites. They are responsible for 45 billion tons of carbon dioxide and methane each year. This is 10 times more than what is produced by humans buring fossil fuel.
By the way, another thing we need to keep in perspective is numbers. We throw around billions and trillions but don't really have a feeling for their magnitude. For example, 1,000,000 seconds is about 12 days, 1 billion seconds is over 32 years; and 1 trillion seconds is from now back to 30,000 B.C.
A recent major attention-getter was the supposed harm caused by deforestation and cutting old-growth timber. The subject is very emotional and more hysterical than scientific. The endangered spotted owl was a pawn in this fight to preserve old-growth timber. We know mature trees and old-growth forests remove 4.5 to 6.5 tons less carbon dioxide per acre per year from the atosphere than younger growing trees. If we are really interested, and we should be, in reducing atmosphereic carbon dioxide, we should be vigorously pursuning reforestation and planting trees and shrubs especially in urban areas where local impacts to the atmosphere are the greatest.
The timber companies in the United States have had a very active program of reforestation. The average annual forest growth is more than three times what it was in 1920 and increased 18% from 1952 to 1977. In New Zealand, and other more developed areas of the world, trees are actually farmed like hay.
Historically, there is no good or widely accepted explanation for why the earth's temperature and climate were as they were at any particular time. No one knows what caused the ice ages and the warm periods in between. No one knows what caused the "little ice age" of the late 17th and early 18th centuries, which was preceded by nearly a century of warming. However, it is pretty clear that humans and industrialization did not cause those warming periods.
Human activity, even now, is minimal compared to natural phenomenon such as volcanoes: Mount St. Helens erupted May 18, 1980. Gases and particulate matter were forced 25,000 meters up, into, and above the atmosphere. 3.6 billion tons of earth was displaced. No one measured the gases released during the eruption (for obvious reasons), but in the remaining seven months of 1980 the volcano released 830,000 tons of carbon dioxide; 200,000 tons sulfur dioxide; and thousands of tons of aerosols, methane, and carbon monoxide.
Mount St. Helens was a small eruption compared to Krakatoa in Indonesia (1883), Mt. Katmai in Alaska (1912), Helka in Iceland (1947), St. Augustine in Alaska (1976) and El Chiucon in Mexico (1982).
Estimates of the air-polluting materials that were released from Krakatoa, Katmi, and Helka, alone, are many times more than the amount released by humans since his beginning on earth. Krakatoa, for example, produced several colder than normal winters and a global temperature drop of 0.3C.
Until the proponents of the man-produced-greenhours-gasses-are-causing-global-warming Theory can scientifically show it true, we should not make drastic changes in our modernized lifestyle. We should not run off half-cocked and propose going back to the horse-and-buggy days of the 19th century, or earlier, with no logging, automobiles, industry, electricity, or other conveniences.
What caused the 80 ppm increase in carbon dioxide during a 100-year period 300 years ago, and the high peak, many times anything measured since, of 130,000 years ago?
This is not to say we should be working to reduce human's adverse effect on the atmosphere. I just ask that we keep things in perspective and not jump to conclusions and create hysteria as the environmental activists and press do.
Also, to narrow down the causes, what we do in the United States will have an insignificant effect of the world's production of greenhouse gases. For example, China alone burns a billion tons of coal per year. They have no other alternative. No matter what the Western world does, we will not materially affect the release of carbon dioxide arising from the human use fo fossil fuels.
Another attention-getter is the disappearing ozone layer. It appears the average thickness of the ozone layer increased in the 1960's and decreased about the same magnituse in the early 1980's. The ozone hole over Antarctica grew in size during the early 1980's, then reduced in size in 1986 and increased again 1987. In 1988 it at first did not appear at all in its normal location, but was finally formed elsewhere at only about 15% of the 1987 size.
The changes in the amont of ozone appear to be related to the production of chlorides and nitrous oxides. There was a widespread, but unproven, fear that there chlorine ions that were destroying the ozone came from chlorofluorocarbons (CFCs). So hysteria has us all give up our hand spray cans of deorodant and paint.
Chloride ions are injected into the stratosphere continuously by natural phenomena:
I've mentioned on only two examples, global warming and the ozone controversy, to show how we must seperate fact from the sensationalism used by the save-the-world-extremists and the press. Three other examples are as follows:
Scientists have recently analyzed ice-pack samples in the Antarctic, Greenland and the Himalayas. They found that precipitation deposited thousands of years ago in those relatively pristine environments had pH values around 4.2 for extended periods of time. In many cases these periods of high acidity lasted several years. Fossil-burning utilities and industrialization-producing sulfur dioxide and other pollutants were not even in existance at that time. However, the periods of high acidity do seem to correspond fairly well to times of major volcanic activity. For example, a rather recent period of low volcanic activity (1920 to 1960) shows lower acidity in the ice even though industrial activity was definitely increasing.
The general public seems to be attracted to the horror stories about cancer, and since the news media are primarily in the entertainment business, scientific accuracy seems to have a very low priority. Activists and extremists use this opportunity often while realists either haven't figured out how to combat them or don't realize they are at war. We've got to bring common sense into protecting the environment.
Nearly all (99.99%) of the carcinogenic materials ingested daily are either natural or produced by cooking or smoking. To avoid ingesting carcinogens you would have to give up nearly all fruits and vegetables, even if they are produced naturally with no chemical fertilizers or pesticides, and much else besides. The proper use of synthetic pesticides and fertilizers has produced enormous benefits to human health and nutrition, without a general harming of the environment, yet there is a major move afoot to eliminate them by the Natural Resources Defense Counsil (NRDC).
Alar is not a pesticide. It regulates growth and keep the apples from falling off the trees too soon, promoting better crispness, taste, and color. NDRC ran the typical mouse tests to show Alar caused cancer. It conveniently wasn't publicised that extrapolating to humans, an individual would ave to eat 12,700 kilograms (28,000 pounds) of apple every day for 70 years to produce cancer similar to that the mice developed. NRDC, in its well publicized attacks on Alar, did not include the additional information that the mice fed one-half the maximum amount (a person eating 6,350 kilograms (14,000 pounds) of apples a day for 70 years) produced no cancer at all. The attacks on Alar produced a near panic. Grocers removed the apples from their shelves fearing law suits. The U.S. apple industry lost more than 200,000,000 dollars. The Environmental Protection Agency (EPA) succumbed to the pressure and decertified Alar without any further scientific data or investigations. EPA even came out later and said the NRDC report was "gravely misleading" and included food consumption data of "unproved validity". However, the damage was already done.
We've all heard of the asbestos-scare fiasco. In 1978 a draft summary was released by the National Cancer Institute (with no authors listed) saying that "2 million cancer deaths would be caused by asbestos over the next 30 years". Johns Manville, Inc. was forced into bankruptcy. It set up an Personal Injury Settlement Trust, which is expected to pay out 2.5 billion dollars by the year 1997. EPA has virtually banned all uses of asbestos by 1997 even though there are important products in which its use is essential, such as brake linings and protective gear for firefighters. EPA studies since have estimated that the "draft summary" estimates were more than 10 times too high. There have been and will continue to be some cancer deaths from breathing asbestos fibers but should the public have been scared, as they were, using the greatly exaggerated figures? It has also been shown that the risk of lung cancer from asbestos is mostly confined to smokers (ninety times greater). What is really causing the lung cancer here?
We now know that long-fiber asbestos commonly found in North America does not usually penetrate into the lung lining and , if breathed in, is easily expelled from the lungs. The short-fiber type that occurs in South Africa is very dangerous. The short-fiber type was imported into the United States to be used mostly in pipe insulation on ships and filters for cigarettes. Asbestos miners in Canada, where much of the long-fiber type was mined, reportedly showed no higher incidence of lung canerr than the general populace.
The United States is into a five to 10 billion dollar test program to remove all asbestos from schools and public buildings. Test on buildings containing asbestos, before its removal, have shown concentrationa of one fiber per 10,000 cm3 of air but, after removal, this number rises to 20-40 fibers per 1 cm3 and can stay at they level for several years. This is a 40,000-fold increase! Why not save everyone money and reduce the exposure by leaving it in place and painting over it? This must be too simple. Also, what about the hazards (to be dreamed up in the future) of the material we are replacing it with?
A piece of old asbestos cement pipe, if pulled out of the grouds, is classified as hazardous waste and must be bagged and disposed of in an approved hazardous-waste disposal site. This is completely unnecessary.
The examples go on and on: PCB's, Dioxin, etc. The United States is spending large amounts of money foolishly on hazardous waste cleanup. Much of the billions of dollars being spent is going to lawyers, not to cleanup wastes. Most of this money could be more wisely used to find a cure or treatment for breast cancer, heart disease, or any number of other diseases.
When are we going to wise up? What can we as scientists and engineers do to bring things into perspective? How can we get across both sides of the picture to the public, with the costs involved, so they can make informed decisions?
I am not a "drop-the-blade-and-go" engineer or an environmentalist against any development. I manage a consulting office that includes both prodevelopment and proenvironmental professionals. We do design and environmental work. Both sides have learned from, and helped, each other.
We must try harder to seperate act from fiction and help the general public understand what is happening to the environment, who is causing it, and what they can do to help. We must counter the alarmists who misuse science to promote fear, trying to stop all development, or spending money foolishly to clean up something that isn't that big a problem.
In closing, the world may well come to an end some day but it will be mother nature, not humankind, that causes it.
This paper appeared as part of the Journal of Cold Regions Engineering, Vol. 8, No. 3, September, 1994. ŠASCE.