The impact of humans
The Earth is the source of all the resources we need, such as metals, plastics and fuels. Humans are very successful living things. We compete with other organisms for many natural resources. These include:
- land (for farms, buildings and roads)
- water (for drinking, watering fields, and industry)
The world鈥檚 human population is increasing, and this means that we are using more resources all the time.
Population growth
The human population in the year 1800 was about 1 billion, and now it is more than 7 billion (more than 7,000,000,000).
Deforestation
Humans have been cutting down trees for thousands of years. We do this to clear land for farming and building, and for wood to use as a fuel or building material.
Forestry is sustainable as long as forests are allowed to replace themselves, or are replanted after felling, but often this is not done. The result is that the world鈥檚 forests are steadily shrinking.
The slideshow maps show the loss of forest across the world over the last 10,000 years:
Image caption, Map showing the forest areas of the world about 10,000 years ago
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Pollution
We produce waste whenever we make or transport objects and substance. Waste materials include:
- household and industrial rubbish
- chemicals from industrial processes
- smoke from burning fuels
- harmful gases from burning fuels
They damage the environment and are a waste of resources.
