Environmental impacts of climate change: Wildlife

By Matt Burdett, 3 April 2018

On this page, we look at the environmental impact of climate change on the spatial changes in biomes, habitats and animal migration patterns.

The nature of wildlife

Climate change will have many impacts on the natural environmental systems that support life. There will be changes in biome distribution, habitat processes and the migratory routes of animals. Other key issues include (EPA, 2017):

  • Timing of Seasonal Life-Cycle Events – such as fertility patterns and nesting amongst birds. Different species that are currently synchronised with one another may adapt differently to climate change, leading to unforeseeable consequences for ecosystems.
  • Range Shifts. Each animals has a range of latitude and altitude that it is suited to – such as an insect that can live in warm conditions near the equator, but can’t survive further towards the poles. As the climate warms up, animals may move further to the poles to keep within their temperature range.
  • Food Web Disruptions. As some species become extinct or shift to new areas, other species could be left without a food supply.
  • Threshold Effects. Some ecosystems can absorb the effects of climate change but then suddenly fail – such as coral, which can suddenly die off due to a complex series of processes. Once the threshold has been reached, it is difficult or impossible for the ecosystem to recover.
  • Pathogens, Parasites, and Disease. As temperatures increase, threats to the health of species that were previously kept in check might be able to reproduce more.
  • Reduction in biodiversity as some species fail to adapt to new climatic conditions
  • Loss of some biomes altogether due to sea level rise – such as coral reefs and mangroves and some polar habitats

Key terms

Biome: A global scale ecosystem type. Biomes are identified by having similar biological characteristics such as vegetation type and soil type. Biomes are closely linked to climate, because temperature and rainfall are controlling factors that determine the vegetation type. Examples include the tropical rainforest, equatorial rainforest, boreal forest, hot desert, tundra, tropical grasslands (savanna) and temperate grasslands (steppe).

Ecosystem: A community of living organisms and their physical environment. Ecosystems occur at a range of scales from very large global systems known as biomes to very small ecosystems such as insects living on a tree.

Habitat: This term refers to the environment in which a particular organism lives.

Migration: The movement of animals from one place to another. Seasonal migration patterns involve a return to the original location each year. Climate change may lead to permanent migration as animals are forced to move away from areas that are hotter, drier and so on.

Changes in biomes (wildlife at the global scale)

Biomes are likely to shift because the type of vegetation in an area is largely controlled by the climate. The climate itself is controlled by several factors, but the most important are altitude and latitude. Altitude refers to height, while latitude is the distance from the equator. In general:

  • Places at lower altitudes are warmer than places higher up, because the greater density of the atmosphere at low altitudes retains heat more effectively.
  • Places in lower latitudes (near the equator) are warmer because the sun is at more of an overhead angle and is therefore more concentrated.

  • Similar effects of altitude and latitude. Source: Cartographers Guild, n.d.

As global temperatures increase, biomes are likely to shift. Places that are next to hot deserts will find themselves becoming more desert-like. This is called desertification. It is happening in the Sahel region, just south of the Sahara Desert in northern Africa. Meanwhile, places that are currently very cold near the Poles are likely to become warmer, so they will have less ice and therefore more opportunity for growing vegetation. Overall, the biome in any given place is likely to switch to one that is generally more suited to warmer conditions. This is already happening, as shown on the map below.

Picture

  • Locations of observed biome shifts during the 20th century. Source: IPCC, 2013.

Changes in habitats (wildlife at the local scale)

Local habitats are likely to change even more radically than biomes. This is because it is not only the climate that will change but also the need for humans to use potentially productive agricultural land even more intensively, along with an increased risk of forest fire, changes in streamflow in rivers, and specific species invading an area because their original habitats have been changed. Furthermore, some of these changes will have an effect on the rate of climate change too – e.g. forest fires may put more carbon into the atmosphere, speeding up the rate of warming.

  • The links between climate change and potential habitat changes. Source: IPCC, 2013.

Animal migration patterns

The changes in biome distribution, and in the ways habitats work, mean that species that can move will do so. Migration can be seasonal or permanent.

Seasonal migration

Seasonal migration is likely to change as the routes that animals previously took are barred (e.g. no water available, or the species that it preyed upon has become extinct). It’s important to note that seasonal migratory patterns are changing because of many factors including deforestation, agriculture, urbanisation, pollution and surface mining.

There have been several studies that have mapped the potential changes in both seasonal and permanent migration due to climate change. The map below shows seasonal migration changes that have occurred due to human impact for specific individuals from species including the stork. Whie most of the species migrated to southern Africa (shown in pink), one bird – named Zozo by the researchers – now stops long before that because there is enough available food in human rubbish dumps (Zozo’s migration is shown in yellow).

  • Changes in animal migration due to human activity. Source: Cheshire and Uberti, 2017.

Although this particular example is just one bird, the authors found many similar cases where the natural migration of animals was affected by human activities including climate change.

Permanent migration

Permanent migration may occur as animals move to find new habitats. One study found that half of the species observed were gradually shifting their permanent location, with land animals moving at around 16 kilometres per decade and marine life around four times faster (Welch, 2017).

The map below is a screenshot of an animated map showing the movements of animals due to climate change – that means it shows how animals might switch their habitats over time, by ‘jumping’ into neighbouring habitats that are similar but experiencing the effects of climate change by a lower amount. The authors recognise that the local pattern will not be so clear, as many of these migratory routes will be blocked by rivers, roads, urban areas, managed farmland and so on.

  • How animals will move to new habitats as a result of climate changes. Source: Majka, n.d.

Sources

Cartographers Guild, n.d. No title. https://www.cartographersguild.com/showthread.php?t=28168&page=2

Cheshire and Uberti, 2017. Where the Animals Go. Via Poon, 2017. See How Human Activity Is Changing Animal Migration Patterns. https://www.wired.com/story/see-how-human-activity-is-changing-animal-migration-patterns/

EPA, 2017. Climate Impacts on Ecosystems. https://19january2017snapshot.epa.gov/climate-impacts/climate-impacts-ecosystems_.html

IPCC [Intergovernmental Panel on Climate Change], 2013. Climate Change 2014: Impacts, Adaptation, and Vulnerability, Chapter 4. https://www.ipcc.ch/report/graphics/index.php?t=Assessment%20Reports&r=AR5%20-%20WG2&f=Chapter%2004 Via https://www.ipcc.ch/report/ar5/wg2/

Majka, n.d. Migrations in Motion. The Nature Conservancy. http://maps.tnc.org/migrations-in-motion/#3/47.64/-111.45

Welch, 2017. Half of All Species Are on the Move—And We’re Feeling It. https://news.nationalgeographic.com/2017/04/climate-change-species-migration-disease/

Environmental impacts of climate change: Wildlife: Learning activities

Questions

  1. Describe at least three ways in which wildlife may be affected by climate change. [6]
  2. Define each of the following terms:
    1. Biome [1]
    2. Habitat [1]
    3. Ecosystem [1]
    4. Migratory patterns [2]
  3. What is meant by ‘altitudinal variation’ in terms of biome distribution? [2]
  4. What is meant by ‘latitudinal variation’ in terms of biome distribution? [2]
  5. Describe how one biome of your choice is changing its distribution. [3]
  6. Outline the links between climate change and habitats. [4]
  7. Distinguish between seasonal and permanent migration. [2]
  8. Describe how season migration might be affected by climate change. [3]
  9. Explain why animals might permanently migrate due to climate change. [3]

Other tasks

The information on this page is presented using several diagrams and maps. How effective are these at communicating their message? Identify the strengths and weaknesses of each image. Extension: Conduct your own research to find better examples of graphics/images that communicate similar ideas.

© Matthew Burdett, 2018. All rights reserved.

All secondary material on this site is clearly referenced and may be subject to copyright restrictions by the original authors. All original material on this page is subject to copyright.