Population growth projections

The current world population stands at 5.3 billion and is growing rapidly (1), Demographers project that the world population will reach 6.1 billion by the turn of the century, approach 8.2 billion by 2025, and probably reach 15 billion by 2100 (2), Never before in history have humans, by their sheer numbers, so dominated the earth and its resources. What is equally alarming is the 1.8% annual population growth rate --a rate 1800-times greater than that during the first million years of human existence. At this growth rate about one quarter million people are added to the world population every day. 

The primary feature of the projected population growth is the increase of the third world from 41/2 to 8 billion people in the next half century. History has shown that the key measure of population welfare and population stabilization is energy use. Today, people in the high birthrate, poverty stricken, low income nations use only a small fraction of the per-capita energy use of the rest of the world.2... 

Over the past several decades, there has been a continuing growth in the worldwide demand for plastics, films and fibers, particularly polyesters. The raw materials that make up these polymers are based primarily on the C8 family of aromatics (C8A)-ethylbenzene (EB), para-xylene (PX), meta-xylene (MX), and ortho-xylene (OX). Polyester (PET plastic), derived from PX, in particular has experienced rapid growth and is projected to see continue rapid growth as many developing countries desire to have the lifestyle flexibility that such readily available, versatile plastics support. While the markets for MX- and OX-derived plastics are smaller (plasticizers and specialty polyesters, respectively), all C8A markets continue to increase with population growth [59],... 

Given projected levels of population growth, world food production must more than triple in the next 50 years to adequately feed 9.6 billion people. A long-term solution may turn on increasing crop productivity on the arable land affected by aluminum toxicity, and citric acid may play an important role in achieving this goal. 

China alone will contribute a quarter of the increase in C02 emissions or 3.6 billion tons, bringing its total emissions to 6.7 billion tons per year in 2030. However, Chinese emissions will still be well below those of the USA. A projected increase in fossil fuel consumption is largely responsible for fast-paced growth in C02 emissions. Of the fossil fuels, coal and oil account currently for the major part of the total energy-related C02 emissions. Factors such as population growth, rising personal incomes, improved standards of living, and further industrialization are expected to have a... 

The amount of pesticides used in Tanzania increased from 330 g capita-1 in 1977 to 500 g capita-1 in 1988. With population growth in the country at 2.7%, this implies a significant increase (140%) in pesticide use. The control of importation, formulation, and use of pesticides is inefficient. Imported amounts can exceed the authorized amounts because of donations and the specific projects that import pesticides without official authority from the licensing agent (Tropical Pesticides Research Institute). 

Figure 25.1 shows active pharmacists in the United States including the new model s projections of pharmacist numbers to 2010, at which time the model estimates 224,524 active pharmacists. In 2000, the model estimated there were 196,011 active pharmacists. The annual growth of the workforce from 2000 to 2010 is projected at about 1.4% per year, somewhat more than the projected rate of population growth, which is about 1%. Based on these estimates, the number of pharmacists per 100,000 population will rise slowly... 

Fig. 4. The history of the major sources of world CO2 emissions from 1860 to 1993 (Houghton, 2002 Marland et al, 2002 Stern and Kaufman, 1998). From the largest to the smallest they are fossil fuel use biomass, which includes deforestation methane, which converts to CO2 in the atmosphere and cement production. Fossil fuel emissions are projected into the future based on proved reserves shown in Fig. 1. Other curves are projected based on projected population growth.

The supply of naturally occurring fresh water available for human use is limited. It consists of nonrenewable sources such as aquifers and other reservoirs that are not recharged as they are used, and renewable sources such as lakes, rivers, reservoirs and other sources that are replenished by the annual water, or hydrologic, cycle. However, the amount of water available in a given location as a result of the natural water cycle is essentially fixed. Thus as the population increases, the annual water supply per person, which is a general indicator of water security, decreases. The per capita water supplies worldwide are approximately one third less now than in 1970 due to population growth since that time. The water supply crises which already exist and are projected over the next few decades have received much attention recently. Population Action International expressed the concern quite... 

FIGURE 19.1 The T-shaped curve of past exponential world population growth, with projections... 

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