Comment: From Geotimes, 1990, p. 6
A revolution in research, especially Earth-Science research, began in the 1970s as the public became more concerned about the environment. It was on the first Earth Day, April 22, 1970, that the famous cartoon character Pogo rendered his immortal phrase, “We have met the enemy an’ he is us.”
However I prefer to begin with the Clean Air Act of 1970 because this was the beginning for major funding for environmental studies. Although the act is not perfect and often criticized, figures from EPA show that particulates, sulfur dioxide, and carbon monoxide all have decreased markedly in our air.
The Clean Water Act of 1972 followed the Clean Air Act. Progress has been slower for water, but some key pollutants, such as lead, have decreased significantly.
We earth scientists know that, “The present is the key to the past,” so we normally look backward in time. In the environmental and natural hazards areas, the present and the past can also be used to forecast the future. Climate is an example of how geologic prediction can be used most effectively. And now, climate issues are of global concern.
We have become increasingly aware through the global politics of the last year, that we are citizens of one world, that many of the actions we take not only affect us but others as well. Global housekeeping is a challenge for us all.
Release of gaseous pollutants into the atmosphere knows no national boundaries. We are learning that things done with the best intentions can foul the global environment. We have learned just how difficult it is to produce something that is totally benign, yet beneficial to humanity. For example, chlorofluorocarbons (CFCs) – those wonder compounds developed as nontoxic, nonexplosive, colorless, odorless refrigerants to replace the dangerous ammonia and sulfur dioxide – degrade the ozone layer in the stratisphere.
Evidence indicates that certain gases (carbon dioxide, methane, nitrous oxide, CFCs, and ozone) are increasing in the troposphere. These radiatively active gases let short wavelength radiation from the sun pass through Earth’s atmosphere yet absorb heat reflected from Earth. In the simplest model, the heat absorbed from the troposphere will be proportional to the amount of these radiatively active gases – the more of these gases, the higher the global temperature. This concept is now well known as the “greenhouse” effect.
If the greenhouse effect develops as general circulation models suggest it will, consequences will accompany increasing global mean temperatures. The global warming will be greater at higher latitudes than near the equator; winters will warm more than summers, and midcontinent areas will experience increasing dryness. Some other possible consequences are that sea levels may continue to rise, perhaps by a half meter or more, and violent storms may increase in number and severity. Increased temperatures in the troposphere could result in cooling of the stratisphere which, with CFSs in the stratosphere, could result in deterioration of the ozone layer.
However, neither rising sea level nor increasing temperature is a necessary consequence of the increasing human contributions of greenhouse gasses. Even with some increase in increased warming, expected increases in resulting precipitation might result in accumulation of snow and ice in polar regions rather than in melting of the ice caps. It is possible that greenhouse could be counterbalanced. For example, warmer temperature should result in more evaporation of ocean water, increasing the humidity of the atmosphere. More humidity means more moisture is available for forming more low-level clouds that could have a cooling effect. The increase in low-level coulds need not be large, only about four percent, to completely counteract the expected greenhouse effect over the next 50 years. Were it not for the geologic record, researchers could easily develop models where the global mean temperature remains constant. However, the geologic record shows that temperature fluctuates and that it is about as warm now as it has been at any time in the last two million years.
All this has been well covered by the news media. But seldom considered is the likelihood of some changes occurring from greenhouse gas buildup even without global warming. For example, increasing carbon dioxide would have a fertilizing effect and increased cloudiness might also result in increased precipitation. Both of these possibilities could stimulate plant growth. Of course growth of weeds would also be stimulated, and increased precitation might cause flooding. Global warming is receiving considerable official attention. The number of congressional hearing on the topic has increased; global change is a presidential initiative; and plans are well advanced for congressional action. Whether we are convinced that the proposed warming will or will not occur, most of us agree that it is dangerous to let these greenhouse gases accumulate.
But we should not delude ourselves. The prime source of basic energy for the next 20 years is going to be coal. The quickest and largest savings on carbon-dioxide emissions can be expected to come from conservation.
Maximizing natural-gas and solar-power use as well as major reforestation efforts will help. The value of nuclear power will be reconsidered. As to long-term options, the major effort in the U.S. in on nuclear-fusion power with a budget of about $350 million a year. Also, several other countries are exploring the use of hot-dry rock geothermal power.
As we work toward a better future, it is bound to be a bumpy course. However, as for now, we can take some comfort that life expectancy is still increasing in spite of current levels of pollution. The global population is growing, but, so far, technology has kept ahead, in spite of changes in climate. Food distribution may be a problem, but currently food production is not.
To create an even better life will be a challenge just as it always has been. This challenge is going to require hard work and all kinds of talent: We will need geologists as well as engineers, philosophers as well as scientists, and, perhaps, informed teachers most of all.
Bruce R. Doe
Mailstop 923, U.S. Geological
Survey, Reston, Va. 2209
The University of Missouri, Rolla, presented Doe with an Honorary Doctor of Science degree last May at its graduation ceremony. The text here is adopted from a speech Doe made for the occasion.
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