ENVIRONMENTAL DEGRADATION AND MANAGEMENT
Professor Gabriel B. Ogunmola, FAS
Chairman, Institute of Genetic Chemistry and Laboratory Medicine
Being Paper delivered at the Conference of the Department of Physics, Faculty of Science,
Olabisi Onabanjo University, Ago Iwoye, Ogun State.
6th August, 2008.
Vice Chancellor, Professor Odutola Osilesi
Dean of Science, Professor Tunde Ogunsanwo
Head of Physics Department, Dr. Kola Odunaike
Special Guest Speaker, Dr. Ayo Coker
Chairman Organizing Committee, Dr. (Mrs.) O. Fasunwon
Very distinguished colleagues.
Forces of Change
In the history of mankind, civilizations have risen and fallen. Cultures of great sophistication have developed on all continents. Societies offering great promise at one time have failed to sustain progress and turned into decay, leaving only fragments of past glories behind due to degradation of environment.
Man has always been striving towards a better life, but progress had been uneven to say the least. In many instances, changes for the better have come to a halt or even regressed. Which are the driving forces behind progress and why are some cultures or our own unable to sustain the forces of progress thus leading us behind in stagnation and decay with consequence of excessive exploitation of scarce resources – human or material?
Science in general and the basic sciences in particular have been and most certainly will continue to be a decisive force for achieving better management of the environment and development. This is in no way an original idea, but it has often been forgotten. The emergence of the industrial societies in Europe and North America, starting in the 18th century, is generally, seen to be the result of new, mechanized methods of production. The results have been staggering in many ways. One may wonder what started this dramatic change in the pace of development. Moreover, so far there seems to be no slackening in the pace. On the contrary, the rate of change is still increasing. The key to this is the new attitude towards science and the laws of nature that developed in Europe at that time.
Since the ancient times man has looked upon nature as the obvious guide to harmony and proportions. Man must work with nature, on nature’s own conditions. To study matter and the laws of nature means to find nature’s own solutions to the problems. The idea is simple and attractive. Evolutionary processes are governed by the laws of nature. Through evolution, nature has found the best and most efficient solution consistent with the laws of nature, and therefore man should learn from the results produced in this way to manage its environment.
If we get to know the laws of nature, why can we not exploit this knowledge and make science work for us? The answer to the question is, of course, that we can make science work for us, and this is exactly what the industrial countries, did a couple of centuries ago. Science provided new ideas lending themselves to new inventions or improvements of inventions.
The immense power of science is apparent and development in advanced countries of the world today would be inconceivable without the support of science and science-based technology.
We must immediately therefore address the old philosophical divide between “science for itself”, which is the structure of science, and “science for our use generally referred to as technology, which can be referred to as function of science. The history of human civilization has shown that the manner of resolution of this divide between structure and function has determined the impact which science has made not only on the society that breeds it, but also on science itself.
It is in the interplay of structure and function of science. It is in this process that the factors of national policy objectives and national plans come in to play in relation to our country Nigeria and indeed the African continent and for this purpose, the relevance to our survival I believe this why you have mounted this seminar.
Threats to Existence
Each generation feels threatened, we are really threatened. Current threats include population growth, lack of energy, poverty and mass starvation, gross pollution of water and air, low life expectancy and rising costs of living, the disappearance of natural resources. Each threat is severe, and the sum is such that we may be the most threatened generation in human history and Africa is the most threatened continent.
But if we are more threatened than those who have been at any other time in history, we are better equipped to understand and meet the threats. We are freer than ever before because of the many choices available to us; choices that were unknown years ago.
Let us explore some of these threats and some choices. The exploration may provide insight into the role of science and the relationship between the form and function of science.
For most of written history, the rate of human population growth was about 0.04% per year and the time required for doubling the total human population about 2002 years. The present worldwide average rate is 50 times as great (about 2 percent per year), giving a doubling time of about 35 years (see Table 1). The growth rate in Nigeria is about 2.6%.
It is increasingly clear that the world’s population cannot continue to increase much longer. Had there been only a dozen people alive at the time of Christ, and had the population increased at the present rate for the past 2002 years, there would now be about 1017 people on earth – a population density of one hundred people per square foot over both land and water.
Table 1: Doubling time of a population is universally proportional to present rate of growth
|Rate of growth (percent)||0.1||0.5||1||2||3||4|
|Doubling time (years)||700||140||70||35||24||18|
Population control is probably a most crucial problem of our time. We have just had an accurate census; but we do a national policy on population control. Many other problems are directly related to rapid population growth and if growth increases much longer, it seems unlikely that we can ever solve many associated problems.
There are three broad choices for controlling population, natural disease based in increasing the death rate which nobody wants, decreasing the birth rate and migration. Both of these are happening now.
Birth control methods are a reliability of almost 100 percent (though that figure will almost certainly never be reached because of chemical variations from one individual to another). Cheaper and more effective methods are now readily available. For example, there is a subcutaneous capsule that will reduce the chances of conception to less than 1 percent over a period of as long as twenty years; such a capsule could be removed at any time a child was desired. Male fertility control is equally being practiced in increasing number. We have a national policy that would need our development objectivity of population growth rate and increase in the standard of living. Four (4) children per family is still rather high, we can cut this by half and improve the quality of life.
In some societies “death control” has long been used to maintain the necessary balance between population size and available resources. Few people today advocate a planned increase in death rates, though war is sometimes excused as being a population control device. Instead, as our knowledge of human physiology grows, “death control” means postponing death, and accelerates population growth by increasing life spans. Research now is expected to extend life expectancies to a hundred years or more but the life expectancy in Nigeria is still less than 60, actually 47 years.
Customarily these are said to be the only three choices available. Let us turn now to some limits that are placed on human population by those things that are necessary for human life, such as air, water, food, environment and health, rather than the raw materials such as copper, iron, and salt, that we need to maintain improved standards and life style standards. We shall, in what follows, assume that each individual will require the same amounts of necessities.
We would perish quickly from lack of air, so it is pertinent to ask how many humans the earth’s air supply can support. Air exerts a pressure of about 15 pounds per square inch; the total area of the earth is 200 million square miles. Thus the atmosphere contains about 1015 tons of oxygen and 5 1015 tons of nitrogen.
At present roughly if each person uses some 200 million kilocalories (kcal) of energy per year (mostly from burning fossil fuels), this means an expenditure of about 102 tons of oxygen per person per year. The present rate of cycling of oxygen through the atmosphere is estimated to be once per 3000 years, making 1012 tons available per year – in the assumed steady state, enough for 1010 people, only three times the present world population.
Nitrogen is an essential element in food, and is present mainly in the form of protein. The per person consumption of protein nitrogen per year is about 25 pounds (1002). The cycling time for nitrogen is estimated at 108 years, giving 2-108 tons per year, or enough for about 1010 people.
These figures are approximate and involve both optimistic and pessimistic numerical assumptions. The attempt here is to give as realistic a maximum population estimate as possible within the simplifications. For example, it is necessary to synthesize nitrogen compounds at the rate of 40 pounds of nitrogen per person per year in order to supply the fertilizer required for current crop yields as the topsoil frequent supply of nutrients after 10 – 15 optimistic mechanical treatment. Clearly atmospheric nitrogen is already inadequate in the face of population pressures. The shortage can be relieved only if synthetic chemical methods are used to shorten the nitrogen cycle.
The atmosphere is not only a source of oxygen and nitrogen; it is also a sink into which we pump many substances. Carbon dioxide build-up is one case in view.
It has been predicted as far back that combustion of fossil fuels would lead to an abnormal rise in atmospheric CO2. The average temperature of the earth’s surface has already risen by 0.2oC and that of the stratosphere 2oC as a result of carbon dioxide build-up and the fact that CO2 is transparent to most solar radiation but not to heat radiated out from the earth. Further heating will cause ocean levels to rise several hundred feet as the polar icecaps melt and dramatic changes in weather.
But we have new choices. Nitrogen compounds are widely synthesized and are becoming cheaper, other fuels, which neither consume oxygen nor release carbon dioxide, would be more available, and the direct conversion of sunlight to storable energy is now feasible. We can benefit a lot from solar energy as the intensity of the su is quite high in Nigeria. Professor Animalu has demonstrated this within his solar washing machine at Nsukka as one of the achievements of science in meeting our human needs.
The total annual rainfall on earth is about –1019 litres. Much falls into the ocean, and much runs off in places inaccessible to man. About 3-1017 litres are actually available per year. At the current average rate of use 107 litres per person per year, this amount of rain would support a worldwide population of 3-1010. Modern technology of water reuse multiplies the supply by a factor of 5 or 6, and large-scale desalination of seawater can soon multiply it by another factor of 10. The cost of desalination has come down rapidly and is approaching the thermodynamic limit discovered by “pure science” years ago.
Available water is unequally distributed over the earth’s surface, making it likely that there will continue to be severing local water shortages, but there is little threat of a worldwide shortage.
Streams, lakes and oceans are not merely sources of water. They are, like the atmosphere, sinks into which we continue to pour great quantities of waste. When the waste input exceeds the amount of oxygen in the water, much of the aquatic life is destroyed, drinking the water is unhealthy, and chlorination and similar treatment must be increased just to make the water barely suitable for human consumption. Making water available and accessible to every individual is a realistic national goal in this country. Many water borne diseases can be eliminated and improved health mostly of the children assured.
A well-fed person consumes close to 3000 kcal per day. The minimum human requirement appears to be about 1000 kcal per square metre of body area (the approximate size of the average person). It is apparent that, if present trends are not altered, the entire population of the earth (on the average) will be underfed throughout this century; half is already underfed today and poverty looms large in many developing countries of Africa. Students already coined 0 1 0, 0 0 1, 1 0 0 for one meal a day profile of no breakfast and no dinner, no breakfast and no lunch and no lunch no dinner respectively even among the moderately elite students.
Food production could be increased almost everywhere. The amount of arable land remained fairly large and underutilized, but food production has not increased significantly. IITA has through the introduction of improved genetic species, improved the tonnage of cassava and new maize hybrid has increased but storage remains a great problem to food storage.
Increased mechanization and energy input is necessary to improve farm yield and fertilizer for increased yield.
Yet agriculture in Nigeria is now at the place where it is impossible to feed even our own population if it were denied chemical and biological controls of pests and chemical fertilizers. Such chemical assistance, much of which is based on a rather detailed knowledge of molecular behaviour in living systems, has certainly increased as it becomes safer for the human consumers. Our available choices will continue to increase as our knowledge of biological systems continues. We need a rapid expansion of agriculture and food production to increase food security in Nigeria.
The solutions must clearly involve, in addition to population control, a major agricultural reform, and a higher and higher dependencies on chemical substances. But note again; solutions are available, choices can be made. For example, available methods of food preservation and enrichment could lead to great net gains in the effective food supply.
The range and efficiency of life are strongly influenced by the environment, especially by the temperature and the humidity. Our ability to construct shelter and to use fire has given us a great advantage over other forms of life by extending our habitable range and increasing our biological efficiency.
One interesting natural adaptation that has enabled human being to overcome a weather problem is illustrated by the correlation between skin colour, vitamin D synthesis, and population distribution. Vitamin D is synthesized in humans by subcutaneous cells, which obtain the required energy from sunlight. Too little vitamin D leads to death from rickets, too much to death by vitamin D poisoning. Dark-skinned persons may obtain too little vitamin D from sunlight in northern latitudes, and light-skinned persons exposed to tropical sunlight may synthesize too much of the vitamin – hence the natural distribution of man by colour. Eskimos get vitamin D from a fish diet and thus survive with very little sunlight in spite of their skin pigmentation. Enough modern foods are enriched by the addition of vitamin D to make availability of sunlight no longer a dominant factor in relating population distribution and skin colour. We have abundant vitamin D that we do not need a natural supplement in the tropic through our skin pigmentation.
The longevity and life expectancy of human species are determined by many factors. Apparently, most of them are chemical and have to do with the rates of critical chemical reactions, which show up in the aging process, sickness, and health.
For most of our existence, the principal sources of sickness, especially among children, have been malaria, bacterial and viral infections and malnutrition.
Antibiotic and vaccines have reduced death rates from these maladies but malaria infestation had remained major problem in addition to the current HIV infection and AIDS endemic and the resurgent tuberculosis.
Medical Sciences are making great strides in combating these maladies and the future of Africa in its economy and well being would depend on efficient remedies and eradication of this scourge and other diseases.
Meanwhile prevention is costly and treatment often entails a protracted regimen of medication that local facilities cannot presently supply and that patients find hard to use. Most people with this illness in Nigeria live on an average low annual income. The cost of medication exceeds patients’ income. What do we do now? How do we go about this new scourge?
Habits and institutions favour this disease, its spread as well as and thwart medical solutions. The disease is almost invariably shaped by patterns of human behaviour, and remedies entail not only medication but also changes in comportment. AIDS in Africa is ravaging. A figure of 6 million profiles in Nigeria is quoted as haven been infected without a major screening going on or is there any organized counseling to reduce its incidences.
Measures of public health may offend indigenous susceptibilities, while medical tests and precautions may be seen as condescending and exploitative but we must take bold steps to deal with this scourge because with its presence we just cannot survive, cannot develop and we cannot be the fittest. Whosoever and whatsoever invented this virus, or designed it, can no longer will it away from the surface of the earth. What do we do and where do we go from here!!
Great progress is also being made in treating functional diseases of the heart and other viral organism and serious investigation is underway into controlling the aging process itself. We shall almost certainly have an increasing ability to control the rate of death and the average age at which death takes place, i.e. life expectancy. The life expectancy in Nigeria is currently below 60 years.
The effect of death control measures on the genetic process is the subject of much current research. It is possible, for example, that sickle cell patient will have prolonged life through our improved knowledge and accompanying therapies, improve the chance that there will be more babies born with sickle cell disease that would survive to adulthood.
The total area of the world is about 200 million square miles; about 60 million square miles is dry land. The present average population density of the world is 50 persons per square mile of land. Some of the most densely populated lands are about 1000 persons per square mile in Netherlands; Japan, 700; India, 400. Australia and Canada are among the countries having the lowest density, with about 5 persons per square mile. If we assume that the whole world could be as populous as the Netherlands, we get a total population of 60 billion, a level that would have be achieved by the year 2100 unless present growth rates decrease between present population density and present adequacy of food supply, correlates hunger and growth rate.
Living species require a certain average minimum area for health and growth. This is true of plants and of predatory animals. It now appears that the minimum for many animals is determined by needs other than such raw materials as food, water, and sunlight. Rats will resort to cannibalism even with an adequate food supply if the population density in a cage exceeds a rather well defined limit, and similar effects appear to be present in other species. There is some evidence that man is similarly affected, it seems that there is a variation in need from one culture to another but that the minimum requirement for space is real and may already be operative in some crowded places. This is why crime increases in large cities.
Each of the problems outlined so far may be solved in a variety of already established ways and our number of choices in most areas is still increasing with time, though this will hardly continue indefinitely. But most of the solutions share a common feature. They all require energy.
Most if not all, of the useful energy supply on earth comes from the sun. some comes in the form of direct sunlight (at the rate of about 1021 kcal per year of which about 50 per cent is immediately reflected back to space, 50 percent is absorbed as heat then quickly radiated to space, and some 0.1 percent, or 1018 kcal year-1, is converted into earth-bound energy, as in wood. Some energy comes from fossil fuels (of which consumption rate is now about 1017 kcal year-1); some from hydroelectric power, although currently these add only a few percent to the supply. Perhaps the most dramatic interpretation is the year 2100, when the rate of energy generation by man on earth will exceed the present rate of energy retention from the sun. From then on the earth will be operating on an energy deficit. Table 2 summarizes the known reserves of the largest energy sources, and their exhaustion periods if the present rate of use continues.
Table 2: Known Reserves on the Large Energy Sources and their Exhaustion Periods at Present Use Rate
|Fuel||Reserve (kcal)||Annual use
|Years until exhaustion at present use rates|
|Oil||1018||3 – 1016||30|
|Coal and gas||3 – 1019||1017||300|
|Solar energy||1020 year-1||–||1010|
As population increases, some demands (for water, for example) increase in a roughly linear fashion. But other demands, especially for energy would increase much more rapidly. We shall have very serious energy production shortage or what is the meaning of NEPA; Never Expect Power Always, despite the presidential deadline.
The present energy consumption is about 2 – 108 kcal per person per year. At this rate the fossil fuels listed in Table 2 would last about 1011 person years, or about thirty years for the present world population. Additional fossil fuels are being discovered. It is clear that fossil fuels cannot supply the long-term energy needs and are going to decline rapidly in the near future as a prime source of energy. Many chemists would argue, even now, that oil, gas and coal are of more potential value as chemicals for synthetic purposes than they are as energy sources. Yet their projected consumption as fuel continues to increase unless the conventional use is changed.
The long-term energy picture for the world is rather favourable; however, nuclear fission is now controllable and is already contributing appreciably to the available energy in some advanced countries. Fission products are difficult to handle, but so is the carbon dioxide from fossil fuels. The direct conversion of sunlight to electricity is a most promising source of energy that may produce no chemical contaminants at all. A principal problem now is to find a cheap material for covering large areas – for example, sheet plastic. The energy received a single desert in the Sahara, 180 by 100 miles in area, could supply the total energy needs of the present world population if it were all captured and converted to useful forms instead of reradiating to the sky.
Knowledge of energy sources has improved and the point at which it should soon be possible to have much more energy available and to harness it much more cheaply, is an area of intense science. Since energy is required to solve most of man’s problems, its increasing availability is most encouraging. That would make the production of energy in this country a priority. We have abundant gas as well as high intensity light radiation to make solar energy a most desirable choice.
One result of scientific research that is of considerable import to any discussion of human affairs and energy production is the observation that energy turns into heat as it is used. Thus energy flows from concentrated sources like the sun to relatively cool places like the earth, with most of the energy on earth turning into heat and warning the earth as summarized in the second law of thermodynamics. In addition to the heating that has resulted from the increasing carbon dioxide content of the atmosphere as well as that due to the large energy output in big cities from burning of fossil fuel from automobile.
The steady-state heat supply on earth has, for the past few thousand years at least, been made up of about 2-1017 kcal year-1 from radioactive and other thermal processes inside the earth, and about 5-1020 kcal year-1 of solar energy. The sum of these has just balanced the radioactive heat losses to space, and the earth’s average temperature has been about constant. We are adding about 1017 kcal year-1 to the total.
The present energy output of 1017 kcal per year is sufficient to warm all the water in all the oceans about 10-4oC per year. This is not a negligible amount of heating, and of course, the heat is not uniformly distributed through the ocean waters. As production and use of energy from fossil and others increases, the rate of heating will also increase. The present rate of increase of temperature in the earth’s atmosphere probably runs about 0.01oC per year, may shortly raise this to 0.01oC per year, or 10oC per 100 years. It is extremely doubtful that the earth could support a large human population if such a rise continued for long. If the earth cannot, we thus by inference need to control our population growth rate as a nation and as a continent.
It is true that there are methods for increasing the rate of heat loss from the earth’s surface, but none presently known can increase the rate of loss as fast as humans are increasing the rate of production of heat.
Thus, in all likelihood, heat production will be a primary limiting factor on human activity and population. It also seems likely that the present rate of heat generation is near the maximum tolerable rate; it may even be too high for a tolerable steady-state situation. However, if the rate of heat generation is slowed, changes due to the rising temperature will also be slowed. The heat will have a chance to diffuse through the oceans, markedly lowering the rate at which atmospheric temperature rises, and the temperatures of ocean, land and air may change so slowly that living organisms will be able to adapt to the change and to slightly higher average temperatures. In fact, there is considerable geological evidence that the temperature of the oceans has fluctuated several degrees in the past. It will probably slowly do so again in the future, and the changes need not even be uncomfortable for mankind. But if the fluctuations become a monotonic trend fed by larger and larger human energy production, the ecological results will almost certainly be catastrophic.
The dissipation of heat is one area in which we seem to have few choices, their number being limited by the laws of thermodynamics. Nor does it seem likely that the number of choices will increase in the future. Of all the threats to the existence of human society, of humankind itself, the most serious – except for the unceasing growth of population – is probably that from the steady increase in the temperature of man’s environment. Yet a leveling off or decrease in energy use will have the immediate effect of exacerbating the present tensions in society.
At the moment, the solution to the heat problem seems to be more intensive use of sunlight. Even now, about 50 percent of sunlight is converted to heat without doing useful work and is then radiated into space. If this unused energy were converted to work, it would probably increase the amount of useful energy by a factor of from 2 to 10 without adding appreciably to the heat that is not radiated into space. And this, of course, would make unnecessary the production of energy in ways that increase the earth’s increment of heat. We spend much effort on the direct conversion of sunlight as energy source as we attempt to increase our generating capacity in the national grip. The actual current effort is minimal, but even so is producing results, which promise real choices for minimizing the heat problem at the present population level.
The Steady State
We were 132 million at the last count population growth is 3.5. We are about to do another head count and we better do it right because it is from it that we would be able to evaluate our threats and make more provision for better choices. The projection is that we shall double in population every 25 years.
The Decisive Moment
- The Environment and the Gap in Development
The gap in the development between us and others in the developed world is not contemporary but historic, environmental and long standing but quite often we blame technology and those who have developed it to suite their own condition for improvement. Hence our potential fertile tropical soil remains fallow. We have often blamed the colonial legacies that disrupted our society such that we have lost control of our environment. The slave trade that depopulated and dehumanized us hoping reparation might substitute for the loss incurred. Could all these be the answer? Certainly not. We must not take the easy way out. We cannot rewrite the past to make it more pleasing, but we must be optimistic that we would develop. The weakening of the constraints of the past would come from science and technology. One thing of which I am reasonably certain is that the great issues of our time, issues involving survival and sustainability, are, in the end, likely to require choices.
Ladies and gentlemen, we stand watching the dawn of a new tomorrow. We need to pool all of our resources if we are going to meet the needs of our time. This is not a time for competition, but rather a time for collaboration, a true partnership with government and with the society.
This is a time to be thankful in our triumph of the human spirit and the many great and clever people we have in our institutions, science departments and researchers and in pursuance of the advancement of knowledge, and renew our faith, over and over again, in the capacity of the human mind and begin a new Renaissance of the human spirit to overcome the degradation in our environment.
The first industrial revolution was the product of a society that had developed a sense of respect and concern to impart, empirical and technical knowledge, and a preference for advancement by competence.
The major reasons for the failure of our past are not to have consolidated and sustained the reforms and achievements of the early years or even the preceding colonial regimes in understanding and valuing our institutions as agents of change. Our government needs to see our institutions, not as partners in development to be supported.
Nigerian institutions and scientific centres are to be developed. First, our political leaders must come out strongly with clear policy orientations to address society’s pressing needs, with a system of innovation for the 21st century. The scientific institutions and the scientists on their part must develop strategies to contribute to meeting these needs. There are challenges ahead and we must all be resolved to offer to our country and our continent the best of our skill, collective will to support progress, banish poverty, eradicate ignorance and so liberate the total human spirit for contribution to national development.
Professor Gabriel B. Ogunmola
August 6, 2008