Impact of Environmental Change

Environmental changes can affect the distribution of organisms within an ecosystem. Some environmental factors that can affect the distribution of organisms include:

  • Temperature
  • Availability of water
  • Composition of gases in the atmosphere

These changes can be geographic, seasonal or a result of human interaction.


Due to increasing levels of carbon dioxide in the atmosphere, the average global temperature has increased. Organisms have adaptations that allow them to survive in environments within a specific temperature range.

For example:

  • The desert fox lives in North Africa, which has very hot conditions. So, the fox has large ears to increase its surface area. This allows it to lose heat more easily.
  • The red fox has adapted to live in cooler areas than the desert fox. This is why it is found in Europe.
  • The arctic fox has adapted to live in extremely cold conditions. So, it has small ears, which reduces its surface area. Therefore, less heat is lost.

As the temperature of the climate changes, this affects the organisms that live there. If the temperature in an area rises, plants that are essential to the ecosystem may be unable to grow. This reduces the amount of food available, which can lead to desertification.

  • Desertification is the process by which fertile land becomes desert.

Organisms that feed on the plant will have to migrate to find food. However, the organisms may move to an area they are not well adapted to. This can lead to extinction.

Water Availability

All organisms need water to survive, so if there is not enough water, some species will be unable to survive. Water is also essential for the growth of plants.

As a primary producer, plants support the whole food web and ecosystem. Plants have adapted to the areas they live in. This is why we find plants in the desert where water is scarce, such as cacti. It is unlikely that we will find cacti in regions where water is plentiful.

As global temperatures continue to rise, water availability decreases, which will have an effect on the distribution of organisms.

In North Africa, every year, wildebeest migrate long distances while following rainfall patterns. They are in search of fresh grazing land and water.

As the Earth’s temperature increases, ice and snow melt at a faster rate, which can lead to a rise in sea levels. This can have a number of impacts on water availability, including increased flooding in some areas and the loss of freshwater sources in others.

Composition of Gases in the Atmosphere

The release of greenhouse gases, such as carbon dioxide, methane, and water vapour contribute to global warming. Environmental change can also change natural systems that regulate atmospheric gases, Deforestation can reduce the amount of carbon dioxide removed from the atmosphere by plants.

Atmospheric gases can affect the distribution of organisms in many ways.

For example, some species are sensitive to air pollution. Some species of lichen are very sensitive to sulphur dioxide, which can be produced when burning fossil fuels. So, we will find more lichen in areas that are unpolluted.