This is the introduction of harmful substances into the environment. The most common pollutants are:
Different animals thrive in different environments, and each has its own natural habitat. When sudden, major changes affect a natural habitat, some species cannot adapt or move and die out. Humans have caused changes in some areas, eg flooding valleys through building dams. These changes have caused the extinction of animals and flora.
In the last 50 years, human beings have destroyed 50 per cent of all forest and woodland. Their reasons include the need for timber, constructions and fuel, or more space to grow crops. Most species, including humans, need the oxygen from trees to survive and the increase in carbon dioxide resulting from deforestation has contributed to the greenhouse effect.
Natural resources are substances that are found on or inside our environment. Non-renewable resources such as coal or oil were formed over millions of years and are limited in supply. They also create pollution when burned. Some natural resources produce no pollution and are renewable, eg wind and solar power. These are often more expensive to harness, and are less reliable.
Average temperatures have increased by nearly one degree Celsius in the last 100 years, and the polar ice caps are melting. According to a report from the Intergovernmental Panel on Climate Change (2015) there is a 95 percent probability that human activity has caused an increase in the Earth’s temperature. It cites human-produced greenhouse gases, such as carbon dioxide, as major contributors to the observed increase in our planet’s temperature over the past 50 years.
A minority claim that climate change is simply a result of a natural cycle. Whatever the cause, the effects include rising sea levels and more severe weather patterns.
In the last 70 years, awareness about the damage human beings may cause to the environment has prompted new legislation, eg insulation in new houses and the use of renewable energy such as solar panelling. Other changes include the introduction of cycle to work and car sharing schemes.