Long-term sustainable solutions:

Preventive actions to reduce habitat destruction, loss of species, urban air pollution, water pollution, environmental ills by using : 1.Fuel efficiency; 2. Renewable fuels; 3. Recycling; 4. Population stabilization; 5. Growth management; 6. Market-based strategies; 7. Corporate and individual actions; 8. Environmental legacy.

International cooperation on acid rains control

The Convention on Transboundary Long-Range Air Pollution, LRTAP (Geneva, 1979).

The aim of the Convention is:

- to limit and, as far as possible, gradually reduce and prevent air pollution including long-range transboundary air pollution;

- to develop policies and strategies to combat the discharge of air pollutants through exchanges of information, consultation, research and monitoring.

Lecture 11

Topic: Human population. Demography. Urbanization

Section objectives:

1. Human populations:Population growth. Limits to growth

2. Basic Demographic processes.

3. Urban problems in developing & developed countries

4. Ways to achieve urban sustainability

1. Human populations:

World population now: 6.93 billion (Jan, 2011)

Demography— is the study of the factors that affect rates of birth, death, and growth in populations. In making predictions about a population's growth, it is necessary to know its age structure.

Current Birth and Death Rates

• Every second: about 4 children are born, while about 2 other people die

72 mln humans added to the world population every year.


Population Characteristics

Demographic transition –theprocesswhereby a country moves from relatively high birth and death rates to relatively low birth and death rates due to improved living conditions, that usually accompanies economic development.

Stage 1 – Preindustrial: high birth and death rates, so population grows very slowly.

Stage 2 – Transitional – high birth rate and lowered death rate, so population grows very rapidly.

Stage 3 – Industrial – a decline in birth rate and low death rate, so slow population growth occurs. In developed countries low fertility rate is due to high female literacy.

Stage 4 – Postindustrial – a population grows very slowly or not at all.


Population pyramids- is the age structure that is illustrated as a pyramid with the length of each tier showing the number of males (left side) and number of females (right side) in a particular age group of individuals: Prereproducti\e Reproductive and Postreprodictive. Because of age structure, a population that reduces its fertility rate to the replacement level (2.1 children)will continue to grow for another 30 to 50 >ears. This phenomenon, called population momentum, occurs because of the large number of prereproductive individuals that exist in the population.

Age group of individuals:

- Pre-reproductive (0–14 years)

- Reproductive (15–44 years)

- Post-reproductive (45 years and older)

Age structure pyramid

These population pyramids, showing distribution of population bv age. indicate that Country B has a much greater growth potential than Country A has stable growing


Replacement level = 2.1 children

2. Population growth. Limits to Growth.


• Overpopulation causes resource depletion and environmental degradation

• Human ingenuity and technology will allow us to overcome any problems - more people may be beneficial

Resources are sufficient to meet everyone's needs - shortages are the result of greed, waste, and oppression:

There is a sufficiency in the world for man's need, but not for man's greed.
~Mohandas Gandhi~

For most populations, limiting factors recognized as components of environmental resistance can be placed into 4 main categories:

– Raw material availability

– Energy availability

– Accumulation of waste products

– Interactions among organisms

World is divided into 2 segments based on economic development:

More-developed countries - 1.4 bln: per capita income > $10,000.

• Europe, Canada, US, Japan, Australia, New Zealand.

• Stable populations.

• Expected to grow 3% by 2050.

Less-developed countries - 5.53 bln: per capita income < $5,000.

• High population growth rates. Will grow 52% by 2050 (86% of world population).


Ecological footprint –is a measure of land area required to provide human food, energy, water, housing, transportation & waste disposal for one person.

To be ecologically sustainable, each person should consume no more than 1.8 ha of land (ecological footprint).

Data in table is given as global hectares per capita. The world-average ecological footprint in 2007 was 2.7 global hectares per person (18.0 billion in total). With a world-average biocapacity of 1.8 global hectares per person (12 billion in total), this leads to an ecological deficit of 0.9 global hectares per person (6 billion in total). If a country does not have enough ecological resources within its own territory, then there is a local ecological deficit and it is called an ecological debtor country. Otherwise, it has an ecological remainder and it is called an ecological creditor country

Последнее изменение этой страницы: 2016-12-12; Нарушение авторского права страницы

infopedia.su Все материалы представленные на сайте исключительно с целью ознакомления читателями и не преследуют коммерческих целей или нарушение авторских прав. Обратная связь - (0.006 с.)