1) Decreasing death rates in poorer countries, due to medical enhancements, better nutrition and improved sanitation.
2) Modern agricultural methods, can now sustain the level of food production, with the level of food demand.
3) High mortality balanced by a high birth rate led to stable populations before the rapid growth in the eighteenth century (the introduction of modern medicine & agriculture)
4) Religious beliefs that promote large families and lack of education for women in poorer countries hamper the ability to control populations.
5) Only Western forms of birth control techniques and educational programs will slow birth rates. In all under-developed countries, providing basic is education is difficult.
The increase in population is not the only pressure on the enviroment. Increasing living standards amongst, developed countries, demands more from the enviroment.
These two factors mean that;
1) Raw materials (including non-renewable energy resources) are rapidly being used up.
2) More and more waste is being produced.
3) Unless waste is properly handled more pollution will be caused.
When the Earth’s population was smaller, the effects of human activity were usually small and local.
More people means less land for plants and animals. There are for main ways that humans reduce the amount of land avaialble for other animals and plants;
1) Building
2) Agriculture
3) Dumping waste
4) Quarrying
More people means more enviromental dammage. Human activity can pollute all three parts of the enviroment:
1) Water-with sewage, fertilliser and toxic chemicals. The use of fertilliser leads to eutrophication.
2) Air- with smoke and gases such as sulphur dioxide, and nitrogen oxides
3) Land-with toxic chemicals, such as pesticides and herbicides. These may be washed from land into water.
An increase in population also means an increase, in agriculture and industry, this increases the level of CO2 in the atmosphere. This is contributing massively to the green house effect.
More demand for land and building resources has led to the deforestation of many countires. Along with millions of species, this also causes a major increase in the greenhouse gas, carbon dioxide. Deforestation increases CO2, in the atmosphere , in two ways;
1) The trees, unsuitable for timber, are burned, releasing CO2 directly into the atmosphere. Microbes also release CO2, by decaying the felled trees that remain
2) Because living trees, use CO2, for photosynthesis, removing these trees, means less CO2 is removed from the atmosphere.
Agriculture and burning fossil fules are necessary for our standards of living, and there is more demand on them as the population gets bigger. Greater care, must be taken to sustain the equillibrium, with our enviroment. The only way to ensure this, is to enforce sustainable development. A way of meeting the needs of todays population without harming the ability of future generations to meet their own needs.
