Population And Environment

POPULATION AND ENVIRONMENT A Complex Relationship Between 1960 and 1999, Earth's population doubled from three billion to six billion people. In many ways, this reflected good news for humanity: child mortality rates plummeted, life expectancy increased, and people were on average healthier and better nourished than at any time in history. However, during the same period, changes in the global environment began to accelerate: pollution heightened, resource depletion continued, and the threat of rising sea levels increased. Does the simultaneous occurrence of population growth and environmental decline over the past century indicate that more people translate into greater environmental degradation? In The Environmental Implications of Population Dynamics, Lori Hunter synthesizes current knowledge about the influence of population dynamics on the environment. Specifically, her report examines the following: •

The relationship between demographic factors-- population size, distribution, and composition-and environmental change.

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The mediating factors that influence this relationship: technological, institutional, policy, and cultural forces.

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Two specific aspects of environmental change affected by population dynamics: climate change and land-use change.

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Implications for policy and further research.

Hunter concludes that population dynamics have important environmental implications but that the sheer size of population represents only one important variable in this complex relationship. Other demographic dynamics, including changes in population flows and densities, can also pose challenging environmental problems. ENVIRONMENTAL IMPLICATIONS OF SPECIFIC POPULATION FACTORS According to recent United Nations estimates, global population is increasing by approximately 80 million--the size of Germany--each year. Although fertility rates have declined in most areas of the world, population growth continues to be fueled by high levels of fertility, particularly in Asia and Africa. In numerous Middle Eastern and African nations, the average number of children a woman would be expected to have given current fertility levels remains above 6.0--for example, 6.4 in Saudi Arabia, 6.7 in Yemen, 6.9 in Uganda, and as high as 7.5 in Niger. Even in areas where fertility rates have declined to near replacement levels (2.1 children per couple), population continues to grow because of "population momentum," which occurs when a high proportion of the population is young. Population Size No simple relationship exists between population size and environmental change. However, as global population continues to grow, limits on such global resources as arable land, potable water, forests, and fisheries have come into sharper focus. In the second half of the twentieth century, decreasing farmland contributed to growing concern of the limits to global food production. Assuming constant rates of production, per capita land requirements for food production will near the limits of arable land over the course of the twenty-first century. Likewise, continued population growth occurs in the context of an accelerating demand for water: Global water consumption rose sixfold between 1900 and 1995, more than double the rate of population growth. Population Distribution The ways in which populations are distributed across the globe also affect the environment. Continued high fertility in many developing regions, coupled with low fertility in more-developed regions, means that 80 percent of the global population now lives in less-developed nations. Furthermore, human migration is at an all-time high: the net flow of international migrants is approximately 2 million to 4 million per year and, in 1996, 125 million people lived outside their country of birth. Much of this migration follows a rural-to-urban pattern, and, as a result, the Earth's population is also increasingly urbanized. As recently as 1960, only one-third of the world's population lived in cities. By 1999, the percentage had increased to nearly half (47 percent). This trend is expected to continue well into the twenty-first century. The distribution of people around the globe has three main implications for the environment. First, as less-developed regions cope with a growing share of population, pressures intensify on already dwindling resources within these areas. Second, migration shifts relative pressures exerted on local

environments, easing the strain in some areas and increasing it in others. Finally, urbanization, particularly in less-developed regions, frequently outpaces the development of infrastructure and environmental regulations, often resulting in high levels of pollution. Population Composition Composition can also have an effect on the environment because different population subgroups behave differently. For example, the global population has both the largest cohort of young people (age 24 and under) and the largest proportion of elderly in history. Migration propensities vary by age. Young people are more likely than their older counterparts to migrate, primarily as they leave the parental home in search of new opportunities. As a result, given the relatively large younger generation, we might anticipate increasing levels of migration and urbanization, and therefore, intensified urban environmental concerns. Other aspects of population composition are also important: Income is especially relevant to environmental conditions. Across countries, the relationship between economic development and environmental pressure resembles an inverted U-shaped curve; nations with economies in the middledevelopment range are most likely to exert powerful pressures on the natural environment, mostly in the form of intensified resource consumption and the production of wastes. By contrast, the leastdeveloped nations, because of low levels of industrial activity, are likely to exert relatively lower levels of environmental pressure. At highly advanced development stages, environmental pressures may subside because of improved technologies and energy efficiency. Within countries and across households, however, the relationship between income and environmental pressure is different. Environmental pressures can be greatest at the lowest and highest income levels. Poverty can contribute to unsustainable levels of resource use as a means of meeting short-term subsistence needs. Furthermore, higher levels of income tend to correlate with disproportionate consumption of energy and production of waste. MEDIATING FACTORS: TECHNOLOGY, POLICY CONTEXTS, AND CULTURAL FACTORS Current technology, policies, and culture influence the relationship between human population dynamics and the natural environment. The technological changes that have most affected environmental conditions relate to energy use. The consumption of oil, natural gas, and coal increased dramatically during the twentieth century, as seen in Figure 1. Until about 1960, developed nations were responsible for most of this consumption. Since then, however, industrialization in the newly developing nations has resulted in greater reliance on resource- intensive and highly polluting production processes. Policy actions can ameliorate environmental decline--as in the case of emissions standards--or exacerbate degradationas in the case in Central Asia's Aral Sea basin, which has shrunk 40 percent since 1960 and has become increasingly contaminated, in large part because of the irrigation policies of the former Soviet Union. Cultural factors also influence how populations affect the environment. For example, cultural variations in attitudes toward wildlife and conservation influence environmental conservation strategies, because public support for various policy interventions will reflect societal values. TWO SPECIFIC AREAS OF POPULATION-ENVIRONMENT INTERACTION: GLOBAL CLIMATE CHANGE AND LAND-USE PATTERNS Two specific areas illustrate the challenges of understanding the complex influence of population dynamics on the environment: land-use patterns and global climate change. Land Use Fulfilling the resource requirements of a growing population ultimately requires some form of land-use change--to provide for the expansion of food production through forest clearing, to intensify production on already cultivated land, or to develop the infrastructure necessary to support increasing human numbers. During the past three centuries, the amount of Earth's cultivated land has grown by more than 450 percent, increasing from 2.65 million square kilometers to 15 million square kilometers. A related process, deforestation, is also critically apparent: A net decline in forest cover of 180 million acres took place during the 15-year interval 19801995, although changes in forest cover vary greatly across regions. Whereas developing countries experienced a net loss of 200 million acres, developed countries actually experienced a net increase, of 20 million acres (see Figure 2). These types of land-use changes have several ecological impacts. Converting land to agricultural use can lead to soil erosion, and the chemicals often used in fertilizers can also degrade soil. Deforestation is also associated with soil erosion and can lessen the ability of soil to hold water, thereby increasing

the frequency and severity of floods. Human-induced changes in land use often result in habitat fragmentation and loss, the primary cause of species decline. In fact, if current rates of forest clearing continue, one-quarter of all species on Earth could be lost within the next 50 years. Global Climate Change Recent years have been among the warmest on record. Research suggests that temperatures have been influenced by growing concentrations of greenhouse gases, which absorb solar radiation and warm the atmosphere. Research also suggests that many changes in atmospheric gas are humaninduced. The demographic influence appears primarily in three areas. First, contributions related to industrial production and energy consumption lead to carbon dioxide emissions from fossil fuel use; second, land-use changes, such as deforestation, affect the exchange of carbon dioxide between the Earth and the atmosphere; and third, some agricultural processes, such as paddy-rice cultivation and livestock production, are responsible for greenhouse gas releases into the atmosphere, especially methane. According to one estimate, population growth will account for 35 percent of the global increase in CO2 emissions between 1985 and 2100 and 48 percent of the increase in developing nations during that period. As such, both attention to demographic issues and the development of sustainable production and consumption processes are central responses to the processes involved in global warming. WHAT SHOULD POLICYMAKERS DO? The policy implications of demographic influences on the environment are complicated and can sometimes be controversial. While some view large, rapidly growing populations in developing regions as the primary culprit in environmental decline, others focus on the costly environmental effects of overconsumption among the slowly increasing populations of the developed nations. These differing emphases naturally point to radically different solutions: slow population increase in less-developed nations or change destructive consumption and production patterns in the more-developed nations. This debate, however, presumes a one-step solution to the complex problems created by population pressures on the environment. Both population size and consumption influence environmental change and are among the many factors that need to be incorporated into realistic policy debate and prescriptions. Examples of policies that could address the environmental implications of demographic factors include policies to promote effective family planning, more effective rural development to slow migration to crowded urban centers, and incentives to encourage sustainable levels of consumption and the use of efficient, cleaner technologies. WHAT SHOULD RESEARCHERS DO? Disciplinary boundaries between social and natural scientists have hindered the study of the interrelationships between demographics and the environment. These barriers, however, are beginning to fall. The trend toward interdisciplinary environmental research must be encouraged, and researchers should continue to improve analytic approaches and collect new data that allow examination of the links between social and natural processes. The use of recent technology (e.g., satellite remote sensing) to study environmental change promises to contribute significantly to expanding knowledge in this area.

Environment and Pollution Curriculum for College in India A Welcome Sign for Environmental Awareness Moment: Environmental science has been a subject of great importance to us from ancient time. However, not much concern was expressed until some signs of its detritions are noticed as a result of human activities. Several governmental and non-governmental organizations have initiated programs to monitor and understand it better. Atmospheric chemistry, pollution, air quality are among the prominent environmental issues of the 21stcentury. Therefore awareness about it must begin at the grass root level through schools. Hence the Supreme Court of India’s directive, mentioned below, comes as a welcome step to help the students across the country to make aware about the environmental science. The Hon’ble Supreme Court in its Judgment delivered on 18th December 2003 in Writ Petition No 860 of 1991 has directed the NCERT to prepare a model syllabus for the Environmental Education to be taught at different grades. The Supreme Court directed all the States and educational agencies in the country to introduce environment as a compulsory subject in all classes in schools up to the higher secondary level from the academic year 2004-05. It directed the National Council for Educational Research and Training (NCERT) to frame a model syllabus for the schools keeping in view the 1991 judgment and submit it before the court on or before 14 th April 2004 so as to enable them to consider the feasibility to introduce such syllabus uniformly through out the country. The direction No 4 issued by the Hon’ble Supreme Court as per its order dated 22 nd November

1991 read thus: “We accept on principle that through the medium of education awareness of the environment and its problems related to pollution should be taught as a compulsory subject. Learned Attorney General pointed out to us that the Central Government is associated with education at higher levels and University Grants Commission can monitor only the undergraduate and postgraduate studies. The rest of it, according to him, is a state subject. He has agreed that the university Grants Commission will take appropriate steps immediately to give effect to what we have said, that is requiring the universities to prescribe a course on Environment. They would consider the feasibility of making this a compulsory subject at every level in college education. So far as education up to the college level is concern, we would require every State Government. and every Education Board connected with education up to the matriculation stage or even intermediate colleges to immediately take steps to enforce compulsory education on environment in graded way. This should be so done that in the next academic year there would be compliance with this requirement”. Hence, the above Supreme Court directive is a positive gesture for environmental science awareness campaign. The concept to save our environment will automatically follow once awareness is created about its importance in the main stream. Now it is left to the implementing agencies as to how fast and effectively they can act on it. In this direction, National Council of Educational Research and Training (NCERT) has initiated to consult and collect opinion of various experts / institutions regarding the perceptions in various dimensions of environmental education at different stages of school education. Some issues pertaining to overall implications like how one should introduce the course without increasing curriculum load and what are the implications of this in teacher’s education, etc are basic issues which can be debated and may be kept aside for the time being. Because this may certainly require a proper balance in overall load on a student by shortening the syllabus of other subjects without compromising the important elements and at the same time full weightage should be given to the new subject. We should start working directly and more rigorously on the content and material to be tough in a systematic manner in different standards regarding the environment subject. The environmental science should be considered as compulsory subject irrespective of the selection of optional subject. In a later stage (say in intermediate or so), this may be included as specialized course rather than subject, which may cover different disciplines of environmental science in detail.

Indo US Workshop “Modeling of Transport of Air Pollution” An Indo US Workshop on “Modeling of Transport of Air Pollutants” has been organized jointly by National Environmental Engineering Research Institute, Nagpur and The Ohio State University, Ohio, USA at Nagpur, India during November 11-13, 2003. This workshop was sponsored by Indo-US, S & T forum, Department of Science and Technology, New Delhi. It was inaugurated by Shri. Suresh Prabhu, chirman, task force for linking of rivers and Ex-Environment Minister, Govt of India. There were number of leading research papers presented in this workshop by several experts from USA and India. The workshop covered vast area to address impact of pollutants on Agriculture, Health and Atmosphere. Dr. Moti L. Mittal and Dr Chhemendra Sharma (who were also the investigators and office bearers of the project) presented preliminary results on the distribution of chemical species (mainly pollutants like O3, NOx, CO, Peroxyacylnitrate) over the selective Indian cities using the Episodic Regional Chemical Transport Model called HANK Model. Hotspots with reference to these chemical pollutants were identified. However such results with 60 Km resolution scale could only present a rough idea about the distribution. The input to such model goes from general circulation models (like MM5), which are highly sensitive to several meteorological parameters. On the other hand regional pollution models suffer from several approximations. The weaker link is the emission inventories for various pollutants (NOX, CO and VOC etc) from various sectors like biomass burning, transport, agricultural, residues, etc. Correct attribution of these inputs in pollution models is most critical for pollution forecasting. The status of emission inventories of various pollutants over India is in its initial stage. In this direction an exciting work on “Gridding CO Emissions Over India using GIS Techniques and Modelling Ozone Pollutants” has been presented by Dr. Gufran Beig (ENVIS Co-ordinator at IITM). The presented results on the gridded inventories of CO over the Indian region using the GIS based modeling, were the outcome of the joint venture of Indian Institute of Tropical Meteorology, Pune, Center for Development of Advanced Computing, Pune and National Physical Laboratory, New Delhi. This paper further elaborated upon the pollution forecasting and the sensitivity of emission inventories over the distribution of the concentration of ozone and secondary pollutants using the global three dimensional chemical transport model being operated at IITM, Pune. Presented result clearly demonstrated an urgent need of systematic gridded emission inventories over the Indian region. This needs to be done if any fruitful and meaningful pollution forecasting modeling has to be carried out for Indian region. In addition to this some more interesting presentations were made related to- Uncertainty Analysis in Air Quality Dispersion Modeling; Air Quality Prediction System; Transport of Particulate and Fine Particulate Matters; Effects of Air Pollution on Agriculture; Impact of Air

Pollution on Soil Health and Productivity of Crops in urban Areas; Air Pollutants of Concern for Human Health; Health Impact of Air Pollution in Rural and Urban India; Indoor Air Pollutants Associated with Solid Fuel Use, etc. In conclusion, it was an exciting meet.