The Population Crisis; Are there more Solutions than what we are currently considering?
F. Farrell, MD
University of Connecticut
14 August 2005
Women, Reproduction and Public Health
Human population growth is based on the same general parameters that affect other animal and plant populations; i.e. birth and death rates. Birth rates may be described with the exponential growth function:
A = A0ekt (Thomas, 1992)
Death rates may be described with the exponential decay function:
A = A0e-kt (Thomas, 1992)
Population growth may be seen as a combination of the two such that the birth rate is offset by the death rate:
A = A0ekt- A0e-kt (Thomas, 1992)
To understand the issues around human population growth, we will first consider bacterial population growth. Bacterial population growth is geometric or exponential. “One cell divides to form 2, which divide again to produce a total of 4 cells, then 8, 16, and so on, the number doubling with each generation”. Most bacterial populations will double (generation time) within one to three hours, some may even double within twenty minutes. If the growth rate of bacterial colonies (populations) were sustained and unchecked by death rates, etc. a single cell could give rise to a colony weighing 1,000,000 kilograms in just 24 hours. “However, growth of bacterial colonies both in the laboratory and in nature is usually checked at some point when the cells exhaust some nutrient or the colony poisons itself with an accumulation of metabolic wastes” (Campbell, 1990).
The human population can also grow exponentially; in fact it has been doing so for the centuries. For example, the population doubled from about 500 million in 1650 to 1 billion by 1850. “The population . . . doubled again to 2 billion between 1850 and 1930, and doubled still again by 1975 to more than 4 billion.” If the present growth rate continues, the earth will have 8 billion human inhabitants by the year 2017, assuming an overall growth rate of 1.7% per year (Campbell, 1990). The anticipated problem is that with an increasing birth rate secondary to improved sanitary conditions worldwide and decreasing death rates secondary to improved health maintenance and medical care, we may reach a point where the world is populated with more people than it can support.
A unique feature of human reproduction is that it can be conscientiously controlled by voluntary contraception or by government sanctions. "Social change also affects birth rates. For example, in most developed countries, many women are delaying marriage and reproduction, perhaps because of better opportunities for employment and advanced education. Current worldwide population growth is a mosaic of various rates of growth in different countries. Some developed countries, such as Sweden, are near zero population growth because birth and death rates balance. The human population as a whole, however, continues to grow because birth rates greatly exceed death rates in most nations, particularly in underdeveloped and developing countries" (Campbell, 1992).
In China, government intervention has attempted to stem the growth of the population by allowing only one child per couple. The policy basically gives incentives to couples that comply and have only one child, and it also exacts punishments on those who do not. There are exceptions to the policy that would allow couples to have a second child, but they are very specific and not applied evenly. Those in lower socioeconomic classes do not have the same access to the assistance that would allow them to legally obtain permission to have more than one child. This has led to gross violations of the reproductive rights of women such as forced contraception, abortion, genetic screening, sex screening, etc. Sterilization of underprivileged groups (people with infectious disease, mental illness, reproductive disease, etc.) is also allowed and even mandated in some provinces. The social implications of more governments taking similar stances as their populations continue to swell is huge.
But the question then becomes, does this policy even work? From 1949 to 1974, the annual population growth in China exceeded 2 percent but in the mid-1970s, however, fertility declined dramatically. The annual population growth rate has remained around 1.5 percent since the mid-1970s. The “one-child policy wasn’t adopted by China until 1979, yet China’s huge fertility drop occurred between 1970 and 1979 when live births fell from 34 per 1,000 people to 18 per 1,000 people. Since the introduction of the one-child policy in 1979, there has been no large drop in fertility and in fact China experienced a slight increase fluctuating around 21 births per 1,000 people in the 1980s” (Overpopulation.com, 2005). Yet even though the impact of the one-child policy has been minimal, “Hua Jianmin, State Councilor and Secretary-General of the State Council, said that the family planning policy launched at the end of the 1970s has successfully pulled back China's runaway population growth in rein. The one-child policy has helped cut down the country's population by over 300 million people and postpone the arrival of 1.3-billion population by four years . . . ‘The policy has contributed to the improvement of the nation's comprehensive power, social progress and enhancement of the people's living standard’” (NPFPC, 2005).
An alternative to such measures would be to change the Petri dish. If we liken the human population to a bacterial population on a Petri dish, then we can deal with the growth of the population in one of two ways, either we decrease birth rates, increase death rates or we do not attempt to alter the birth and/or death rates and transplant a sizable portion of the population to another Petri dish. Mars is showing promise as one such possible option. If we are able to get to mars safely and terraform it in some way, we could one day colonize it with our excess occupants and so provide a relief valve of sorts for the earth.
In a recent press release President Bush has outlined some very impressive goals for our nation’s space agency:
“Our first goal is to complete the International Space Station by 2010. We will finish what we have started, we will meet our obligations to our 15 international partners on this project. We will focus our future research aboard the station on the long-term effects of space travel on human biology. The environment of space is hostile to human beings. Radiation and weightlessness pose dangers to human health, and we have much to learn about their long-term effects before human crews can venture through the vast voids of space for months at a time. Research on board the station and here on Earth will help us better understand and overcome the obstacles that limit exploration. Through these efforts we will develop the skills and techniques necessary to sustain further space exploration.
To meet this goal, we will return the Space Shuttle to flight as soon as possible, consistent with safety concerns and the recommendations of the Columbia Accident Investigation Board. The Shuttle's chief purpose over the next several years will be to help finish assembly of the International Space Station. In 2010, the Space Shuttle -- after nearly 30 years of duty -- will be retired from service.
Our second goal is to develop and test a new spacecraft, the Crew Exploration Vehicle, by 2008, and to conduct the first manned mission no later than 2014. The Crew Exploration Vehicle will be capable of ferrying astronauts and scientists to the Space Station after the shuttle is retired. But the main purpose of this spacecraft will be to carry astronauts beyond our orbit to other worlds. This will be the first spacecraft of its kind since the Apollo Command Module.
Our third goal is to return to the moon by 2020, as the launching point for missions beyond. Beginning no later than 2008, we will send a series of robotic missions to the lunar surface to research and prepare for future human exploration. Using the Crew Exploration Vehicle, we will undertake extended human missions to the moon as early as 2015, with the goal of living and working there for increasingly extended periods. Eugene Cernan, who is with us today -- the last man to set foot on the lunar surface -- said this as he left: "We leave as we came, and God willing as we shall return, with peace and hope for all mankind." America will make those words come true.
Returning to the moon is an important step for our space program. Establishing an extended human presence on the moon could vastly reduce the costs of further space exploration, making possible ever more ambitious missions. Lifting heavy spacecraft and fuel out of the Earth's gravity is expensive. Spacecraft assembled and provisioned on the moon could escape its far lower gravity using far less energy, and thus, far less cost. Also, the moon is home to abundant resources. Its soil contains raw materials that might be harvested and processed into rocket fuel or breathable air. We can use our time on the moon to develop and test new approaches and technologies and systems that will allow us to function in other, more challenging environments. The moon is a logical step toward further progress and achievement.
With the experience and knowledge gained on the moon, we will then be ready to take the next steps of space exploration: human missions to Mars and to worlds beyond” (White House, 2004).
These aspirations are not as far fetched as some may believe. In the 1960's when Kennedy proposed to put a man on the moon, he was met with skepticism, but the skeptics were proved wrong when the US succeeded. There are plans that are being considered that involve the equivalent of Saturn V booster rockets going to mars and accomplishing the mission in stages. For example, he first rocket would carry equipment to the Martian surface and begin the process of producing rocket fuel (methane/oxygen) for the trip back to earth. This fuel will be created from raw materials on the Martian surface (carbon dioxide), and the second rocket would carry the crew. Using technology that we already have instead of relying on creating large science fiction like space ships would make a trip to the red planet a very realistic and achievable goal (Zubrin, 1997).
References
1. Campbell, Neil A. Ecology. Biology Second Edition. Benjamin/Cummings Publishing Company, Inc. Redwood City, CA., 1990. pp. 1088-9.
2. Campbell, Neil A. The Evolutionary History of Biological Diversity. Biology Second Edition. Benjamin/Cummings Publishing Company, Inc. Redwood City, CA. 1990. pp. 528-9.
3. Thomas, George B and Finney, Ross L. The Calculus of Transcendental Functions; Growth and Decay. Calculus and Analytic Geometry 8th Edition. Addison-Wesley Publishing Company, New York, 1992. pp. 432-433.
4. China's One Child Policy. Overpopulation.Com. http://www.overpopulation.com/faq/Population_Control/one_child.html. Last visited 01 August 2005.
5. Zubrin, Robert. The Case for Mars; The Plan to Settle the Red Planet and Why We Must. Touchstone, New York, 1997.
6. President Bush Announces New Vision for Space Exploration Program. NASA Headquarters. Washington, D.C. January 14, 2004. http://www.whitehouse.gov/news/releases/2004/01/20040114-3.html. Last visited 01 August 2005.
7. China Adheres to Family Planning to Keep Low Birth Rate. National Population and Family Planning Commission of China (NPFPC). 10 July 2005. http://www.npfpc.gov.cn/en/en2005-07/enews20050711-1.htm. Last visited 10 August 2005.
