human population explosion

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					Human Population Explosion
   Homo sapiens, the humans are relatively recent
    arrivals in Earth’s history.

   But their influence on the environment is very great.

   The explosive growth in the human population has
    had dramatic consequences for the environment and
    for other organisms
How quick is the population growing???

  Rate of increase = births - deaths

 Though birth rate remains constant or
 has a slightly drop, but the death rate
 drops rapidly.

 The population has grown at an
 ever-increasing rate!

It’s just like a explosion!!!!!
The Human Snowball

“Population Explosion”

-Human population grows so fast

->>exceeds the carrying capacity of the   More and more people live
   environment                            on the Earth,
                                          As a result , a large number
                                          of human may die.
    >> human lives are threatened.
   Cause Of Overpopulation
1. Change in methods of food production?

2. Agricultural Revolution?

3. Industrial Revolution?

4. Progress in medicine?
The significant rise in
population growth rate

1st increase in population growth rate:
Age of colonization begins
(More space for living)

2nd increase in population growth rate:
Agricultural + Industrial Revolution
(Food production increased)

3rd increase in population growth rate:
Medical Revolution
(Mortality Rate decreased)
The Domino Effect of the development of humans

                                    Population increase
          The other Domino Effect

                                                          Population increase
•Control of harmful bacteria made water safer to drink
•Sewage disposal systems
•Things for daily use are made which could be easily washed
•The new medicine was introduced
•Living Standard improves
Problem posed by overpopulation

 Ⅰ   Social Problems

 Ⅰ   World Food Problem

 Ⅰ   Impact to Environment
 1. The Social problem of the overpopulating

     Over-crowded
     Conflict --> war
     “Aging” problem in developed countries
     Other moral problems

Those would not be discussed deeply, just be mentioned only.
2. The World Food Problem
Which is the most serious social problem of the overpopulating

 1. Political instability

 2. Unfair trading policy

 3. Uneven distributed food supply
                                                        Famine in less-
 4. Unbalanced population distribution
                                                        developed countries
 5. So much food is wasted

 6. Deforestation inhibits food production

 7. Natural disasters
  The cause of world food problem
1. Political instability:

   - Hinder the export and import of food in the less-developed countries

   - War  destroy the agriculture  less food produced

2. Unfair trading policy:

  the government and businessman from well developed countries ( such as USA)
  deprive the less-development countries by selling the low cost food to destroy
  the agriculture of those countries.
 3. Uneven distributed food supply:
    Though food production is increasing faster than the population.

          -- 1/3 world population (well developed countries)
             consume ½ world food supply

4. Unbalanced population distribution:
   population of less-developed countries >>> population of well developed countries
   consumption(well developed countries)>>>consumption(less-developed countries)
5. So much food is wasted:

   Wasteful eating habits of the people

6. Deforestation inhibits food production:

   Soil erosion -> soil no longer fertile

7. Natural disasters:

   Droughts, floods, pests

  Slow-down of food production
                                                                                             Country      Population at
   Africa Food Crisis
   If the population still keep on increasing,
    the food problem will be worsen                                                          Burundi      2 million

                                                                                             Djibouti     230,000

                                                                                             Ethiopia     > 10 million

                                                                                             Kenya        3.5 million
                                                                                             Malawi       4.9million
                                                                                             Mozambique   801000
                                                                                             Somalia      2.1million
                                                                                             Tanzania     3.7million
   Source: USAID. Executive Overview of Food Security in Sub-Saharan Africa, 15 Feb 2006;
    for Burundi figure, News from Africa
                                                                                             Zambia       1.4million
How to solve this problem?

•The food aids

•Teaching the agriculture technology to the people in those countries

•GM food !!!

•New policies to the agriculture and trading system.

•Reduction of energy loss and food loss
 -reduce the energy loss during TROPHIC TRANSFER , such as eat plants
 -reduce the waste of food
GM engineering

   Genetic engineering, genetic modification
    (GM, 基因改造) and gene splicing are
    terms for the process of manipulating
    genes, usually outside the organism's
    normal reproductive process.
    GM food

   Genetic Modified food can benefit the food
    in the following categories:
    - Taste
    - Yield
    - Nutrition value
III. Impact to the environment
 The environment has largely destroyed by
  us. There are a lot of environmental
  problems. Air pollution, land pollution and
  water pollution.
 As the human population increase, the
  demand of natural resources increase as
   Air Pollution Land Pollution Water Pollution
    -Carbon monoxide -Waste disposal Toxic chemical
    -Sulphur dioxide    -pesticides   Oil
    -Nitrogen dioxide
 A large area of forest was pulled down by
 Lots of organisms lost their habitat.
 Soil erosion
 Desertification
   The community of Hong Kong disposes about
    17,900 tons of solid wastes every day. Of this,
    7,500 tons are domestic waste, 1,800 tons are
    commercial and industrial waste and 7,500 tons
    come from construction activities. The municipal
    waste production amount of each person is
    about 1.4 kilograms per day.

   Hong Kong only got a population of 7 million,
    can you imagine the amount of waste produce
    each day in the World, which got a population of
    14 billion?
 Green House Effect
 In 2006, the average temperature or Hong
  is 23.6 , which is the highest record.
 Increasing concentration of greenhouse
 Lead to Global warming
Exploitation of resources
   Renewable Resources – resources that can be
    regenerate fairly rapidly through natural
    processes. E.g. Oxygen, Minerals in soil.
   Non renewable resources – resources that
    limited in availability. They are fixed in total
    quantity in the Earth’s Crust and are not
    replenished by natural processes in short time.
    E.g. Fossil fuels
Are you noticed our resources are
   Resources like coal and oil are non
    renewable. Once they had depleted, we
    will lost the access of almost all our
Why should have population control?

   The critical question is: In the present of such a
    huge human population, can the natural
    environment be maintained in a condition that
    will supply all living things with the required food,
    water, and space?

   An immediate task must be to reduce the birth
Population Control
   The Earth has its capacity, its resource will
    be used up one day. if the population keep
    on increasing, the problem of food and the
    problem of pollution will be worsen
    Controlling the population is critical to savi
    ng the environment from hazards of polluti
  Population Control Policy
China   : one family one child
Hong    Kong (past): 2 children is
India  :
-in the mid 1970s
-concentrated on male sterilisation.
-strong resistance developed to the
concept family planning.
Tunisia  and Jamaica:
-improved the provision of freely
available family planning advice and
-introduction of education skills and a
general raising of the economic
-improved the health of mother and
the child by preventive medicine.
   Population control is fundamental and
    essential as to avoid long term damage to
    the environment as a consequence of acid
    rain, green house effect and possible
    Global Warming, and the threat to the
    ozone layer.