What are the effects of changes in the global population?

The earth’s population is growing fast, and the rate seems to be accelerating. In 1927 – less than a hundred years ago – there were two billion people on the planet. By 1974 this number had grown to four billion. Today (2012) it is estimated there are over seven billion people alive on earth.

However, population is a complex issue, and some experts believe the birth rate is slowing down – at least in some countries. As they progress towards an industrialised economic system most countries pass through five stages of population growth, known collectively as the demographic transition model. The five stages of this are:

1 High birth rates, high death rates. Population stable.

2 Birth rates remain high but death rates drop dramatically.

3 Population grows rapidly but gap between birth and death rate narrows.

4 Birth rates fall due to contraception and education. Death rate also falls.

5 Low birth rates and low death rates. Ageing, shrinking population.

Many ‘Western’ countries are now in

stage 4 and in some cases (possibly Sweden) stage 5. However many developing nations (such as Bangladesh) are still in stages 2 and 3, and their populations are growing much faster than those of Western nations.

Population is affected by a number of factors, including:

Urbanisation: More than half of the world’s population now live in or near a major city, which means better health care and better access to food, so death rates fall.

Agricultural change: As farming becomes more efficient, more people are able to feed their children. Child mortality drops. Death from famine drops.

Education: As people become more aware of basic hygiene infection drops. Contraception becomes more popular. Educated people tend to have fewer children.

The emancipation of women: When women are able to go out and work they are less likely to stay at home producing children. Women who have the choice tend to have fewer children and later in life.