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 greenhouse gases 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 is native to North Africa, which has very hot conditions. The fox has large ears to increase its surface area, which allows it to lose heat more easily.
  • The red fox, found in Europe, has adapted to cooler areas than the desert fox.
  • 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, it 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 and it’s also essential for the growth of plants. 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 are specifically adapted to the regions in which they thrive. 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.

Every year in North Africa, wildebeest migrate long distances, 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, certain species of lichen are particularly sensitive to air pollutants like sulphur dioxide, which can be produced when burning fossil fuels. So, we will find more lichen in areas that are unpolluted.

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