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’s 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).

Graph shows population in billions. The population is steady, at just over 0 billion, until 4000 BCE, when it begins to rise. At around 1000 CE there is a sharper increase.A graph to show the population growth over the years


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’s forests are steadily shrinking.

The slideshow maps show the loss of forest across the world over the last 10,000 years:

Map shows areas of forest at around 8000 BC

Map showing the forest areas of the world about 10,000 years ago


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.

Traffic congestion at a standstill in both directions on M25 motorway
Many harmful gases are emitted from motor vehicles