Effects on Human Activities and Population Growth

Effects on human activities and population growth.

For many thousands of years people lived on the Earth in quite small numbers. There were only a few hundred million of us! We were scattered all over the world, and the effects of our activity were usually small and local. Any changes could easily be absorbed by the environment where we lived. But in the last 200 years or so, the human population has grown very quickly. At the end of the 20th century the human population was over 6 billion, and it is still growing.

If the population of any other species of animal or plant had suddenly increased in this way, natural predators, lack of food, build up of waste products or disease would have reduced it again. But we have discovered how to grow more food than we could ever gather from the wild. We can cure or prevent many killer diseases. We have no natural predators. This helps to explain why the human population has grown so fast.

Not only have our numbers grown hugely, but in large parts of the world our standard of living has also improved enormously. We use fossil fuels like oil to produce electricity. We also use it to move about in cars, planes, trains and boats at high speed and to make materials like plastics. We have ore than enough to eat and if we are ill we can often be made better

Overpopulation (also called over inhabitation) refers to a condition where an organism's numbers exceed the carrying capacity of its habitat. In common parlance, the term usually refers to the relationship between the human population and its environment, the Earth. Overpopulation is not a function of the size or density of the population. Overpopulation is determined using the ratio of population to available sustainable resources. If a given environment has a population of ten, but there is food or drinking water enough for only nine, then that environment is overpopulated; if the population is 100 individuals but there is enough food, shelter, and water for 200 for...