Our Precarious Planet

A cough on Earth today

melts glaciers

as a man steps onto an escalator,

headed straight down.

Yesterday I attended a lecture at the Institute of the Americas on the UCSD campus. The title of the talk was "Global Climate Change and the Making of a Report to the President of the United States." The speaker was Dr. Ralph Cicerone, Professor of Earth Science as well as Chancellor of the University of California at Irvine, and an expert on the greenhouse effect. He began his talk by defining the greenhouse effect, which results from an interaction of gaseous constituents in the Earth's atmosphere with radiation from the sun. While Mars, for example, lacks a gaseous atmosphere and is a cold planet, both Earth and Venus are warmed by the heat absorptive characteristics of their atmospheres.

Dr. Cicerone pointed out the tremendous potential of solar power. The human population utilizes less than 0.01% of the incident energy from the sun that hits the Earth. Instead we use fossil fuels: oil, natural gas and coal, as primary sources of energy. The combustion of these carbonaceous fuels for the purposes of running our cars, keeping us warm or cool and powering our industrial concerns results in the release of CO₂, the principal greenhouse gas in the atmosphere. Additional CO₂ release results from the burning of tropical rain forests and other wooded areas worldwide in an effort to produce new agricultural land to grow the crops and animals that feed the human population.

Purely as a result of human activities, an estimated 6-12 billion tons of CO₂ are released into the atmosphere annually, corresponding to one to two tons of CO₂ per person per year. Roughly three-quarters of this results from the burning of fossil fuels while the remaining quarter is due to the loss of organic matter associated with land clearing, particularly in the tropics. It takes about 100 years for this amount of CO₂ to be recycled into non-atmospheric carbon as a result of microbial and plant photosynthesis!

We also generate other greenhouse gases such as methane (CH₄), the second most important greenhouse gas, and nitrous oxide (N₂0). These gases have increased dramatically in the Earth's atmosphere since the beginning of the industrial era in 1850. The figures are staggering. The CO₂ levels have increased over 25% while methane has more than doubled! Greater than 90% of the methane generated is made biologically, and less than a quarter of this is produced in natural wetlands; the majority is produced by microbial activities in domestic animals and rice paddies. Moreover, that produced in rice paddies exceeds that produced in ruminant animals by almost 50%. Clearly, the problem would not disappear if the entire human population were to become strict vegetarians!

Recognizing that the human population is changing the gaseous content of the atmosphere, the next question is, are these gases changing the climate? Accurate measurements of the global temperature have been followed since 1880. The results clearly show that the Earth's temperature has increased, but only to a modest extent, about 1.5º F over these 120 years. This seems a minimal increase, perhaps not worth worrying about, until the data are analyzed in greater detail. From 1880 to nearly 1980, global temperatures were essentially invariant, and almost all of the measured increase occurred during the past 20 years.

Conceivably, the climatic change occurring between 1980 and 2003 might have resulted from fluctuations in solar output. Fortunately, solar energy production can be, and has been measured with great accuracy. Indeed the sun does vary in energy yield over time, but it does so to a minimal extent and with an 11-year cycle. Over the past 23 years there has been no net increase in solar yield; nor has the level of incident solar radiation entering the Earth's atmosphere increased. The reasonable conclusion that can be reached from these facts is that human activities have been directly responsible for the documented global warming.

These facts lead to the inevitable question regarding future trends. To what extent can we expect global warming over the next 100 or 200 years? What will the average temperature of the Earth be in 2100 or 2200? Assuming that the current trends of atmospheric CO₂ and CH₄ accumulation due to human activity continue proportionally to the human population, and assuming that this population will continue to increase to the projected 10 billion within a few decades, we can expect the average temperature of the Earth to increase at least 10º to 15º F by the year 2100 and by more than twice this value by the year 2200. This means that for Arizona or an inland area of California, where the summertime temperatures normally range between 90 and 110º F, those temperatures will be minimally 100º to 120º F. in 2100 and easily 120º to 140º F by 2200. For wealthy nations that can afford air conditioning, this may not affect personal lifestyles dramatically. However, the more extensive use of energy-dependent cooling systems will only enhance the release of greenhouse gases. What about the poorer nations, particularly those in the tropics? There, temperatures will be unbearable, and the economic means to correct the problem will not be available. The obvious consequences will be mass migration of the human populations away from the equator towards the cooler parts of the Earth's surface.

Higher global temperatures will have dramatic consequences worldwide. For example, it will have a significant effect on the availability of water. The evaporation rate will increase, causing enhanced humidity and precipitation. The net result will be that arid regions will become even drier, and the incidence of drought will increase. In colder climates, snow will melt earlier, changing conditions that are important for the maintenance of many life forms. In all ecosystems the microbial flora as well as that of the plant, animal and fungal kingdoms will be affected as their environments change at a much faster rate than life can evolve.

Global warming will affect all life forms, humans included. There is no way to predict exactly how these changes will affect human life, but some consequences are almost obvious. Agriculture will need to move North; Northern Canada, Alaska and Russia may be the greenbelt of the world in 2100 and after. The vast deserts of the world will be unbearable with summer temperatures that will never drop below 110º F. Much of the United States will be arid land unable to support almost any form of plant life. The human as well as the plant and animal populations will be restricted to a narrower surface area of the globe.

What will the consequences be to human health? How quickly can the human population adapt to these altered conditions? These are the most difficult questions to answer. With ambient temperatures increasing towards body temperature (98º F), and with atmospheric water vapor increasing correspondingly, one can predict that pathogenic bacteria and viruses, which are adapted to mammalian body conditions, will be able to survive outside of the body for longer periods of time. This means that bacterial and viral diseases currently transmitted only by direct physical contact between human individuals may be airborne pathogens of the future. It may be possible to catch syphilis, gonorrhea and AIDS by breathing the air exhaled by an infected individual. Catching these potentially fatal diseases would then be as easy as catching the common cold. Moreover, with the populations of virtually all animal species diminishing, and only the human population and their domestic animals increasing, the evolutionary pressure for animal pathogens to acquire the ability to cause disease in humans and their food sources will increase, greatly enhancing the fitness of the infecting virus, bacterium, fungus or protozoan.

Over the past 60 years mankind has been able to keep these infectious organisms in check by the use of antibiotics, antifungal agents and antiviral drugs, but the more we use these antimicrobials in medicine and agriculture, the greater the advantage to these pathogens to acquire resistance. The shocking appearance of drug-resistant bacteria causing hospital-acquired infections, and the ease with which AIDS-causing HIV mutates to evade the few drugs that have been developed to combat this disease, illustrate the inevitable consequences of the evolutionary process. Those who have confidence in the scientific revolution should note that in spite of the hundreds of billions of dollars spent to combat AIDS, and in spite of the efforts of thousands of capable scientists working over a period of a couple of decades, we still have no effective cure, and no vaccine against HIV. Moreover, recognizing that HIV may have hopped to humans from another primate species less than 50 years ago, reveals the insurmountable problems the human population is likely to encounter in the foreseeable future when many other animal pathogens choose to invade humans.

Many folks I've talked with say, "Well, I'm sure glad I'll be gone before all this happens." Unfortunately, they think only of themselves. But what about our children and grandchildren? They will be here to experience these disasters. If we care about them or about the human race in general, we must take cognizance of the immense problems created by an excessive human population and take an international approach to bringing it under control. We must learn to live in harmony with nature rather than attempting to control nature as these efforts have met with consistent failure. Whenever we meddle with the world, even when our intentions appear most laudable, there seem always to be side effects that have long-term deleterious consequences. It is time to accept the fact that science has not, is not and will not solve the immense problems we face as inhabitants of planet Earth.

A friend of mine noted that the human population is to the Earth as a cancerous cell is to a healthy organism. The cancer cell proliferates at an uncontrolled rate until it eventually kills the host organism. Most cancer patients had done little to prevent the development of cancerous transformation in their bodies until it was too late, when the expensive and often devastating treatments proved futile. If they had used recognized preventative measures such as exercise, proper diet and avoidance of smoking and excessive drinking, these cancers would not have developed.

In like measure, the human population has grown out of control to the point where we're choking the life out of our planet. Thousands of species are becoming extinct every day thanks to us. The estimated loss of living species in just one year, in the year 2000, approached 50,000. This rate of extinction is more than 10,000 times the natural extinction rate that had existed for the 50 million years before the introduction of agriculture.

The only rational cure to the cancer that plagues our planet is to reduce the human population. I believe this can only be achieved by changing our value system through education, and by the imposition of strict international regulations. If these measures are not taken, we can be sure that worldwide starvation and pestilence will take its toll. The cost will be human suffering as never before known to mankind. While starvation will affect the poverty-ridden nations primarily, drug resistant microorganisms will ravish the poor and rich alike. There will be no escape. We have no other choice if human suffering is to be avoided.

In response to the global warming report prepared by Dr. Cicerone and the scientific panel, the Bush administration seriously considered and debated the contents of that report. Some officials advised that the U.S. take a lead in international efforts to control global warming while others felt the U.S. should simply withdraw support and assume a policy of isolationism. This latter course was adopted. This decision was not a complete surprise in view of the earlier Bush decision to do away with all U.S. support for international birth control, one of the very first actions taken when Bush entered the White House. As noted by Albert Einstein, "A major difference between genius and stupidity is that genius has its limits."

Withdrawal of the U.S. from the preexisting global warming treaty, the Kyoto Accord, which had been signed by the earlier President Bush, angered many of the world's nations. Not surprisingly for a highly industrialized nation, the U.S. is the number one cause of pollution and CO₂ release. Part of the anger expressed by other nations, as well as by many knowledgeable individuals both within and outside of the U.S., resulted from the fact that no action could be taken to curb the damaging activities of the mightiest nation on Earth. There is no international governing body that has the jurisdiction to reprimand and punish an ignorant but powerful nation.

In retrospect, individual efforts to curb the deleterious activities of human society in causing global warming, depletion of the ozone layer, pollution of the environment, or extermination of the species can represent no more than a "spit in the bucket". As long as the human population is out of control there will be no cure for our planet's cancer. Unless the population is dramatically reduced, we can only achieve a brief postponement of the ultimate, dismal fate of planet Earth.

Population control is and will remain the only solution, but it will be exceedingly unpopular. It is vehemently opposed in part because many individuals in our societies believe that procreation is one of their "God-given rights." After all, the Judeo-Christian-Muslim Book of Mythology does state: "And God blessed Noah and his sons, and said unto them, Be fruitful and multiply, and replenish the Earth" (Genesis 9:1). That was great advice 3000 years ago, but it's terrible advice for the 21^st century. While we have certainly multiplied, we are not replenishing the Earth! If God were around today, he would surely throw out the old book and write another. In fact, since men wrote the old one, it's our duty to write the new one. We can either face our responsibilities squarely and act accordingly, or we can bury our heads in the sand and wait for the devastating consequences. The choice is ours to make.

Further Reading