Effects on the Biosphere (SL IB Geography)

Revision Note

Jacque Cartwright

Last updated

Impacts on Biomes, Habitats & Animal Migration

  • Ecosystems and biomes play a key role in carbon cycling
  • The availability of moisture for plant and animal distribution and growth is important
  • Changes in temperature, rainfall, and habitats affect species' survival, migration patterns, and interactions
  • This results in changes to ecosystem functions and services
  • Some places will improve conditions for crops and ecosystems, while others will suffer
  • Biomes may move north or south because they need specific climate conditions:
    • Polar and tundra biomes are at risk because they cannot move any further north or south
    • Rising sea temperatures and ocean acidification have caused coral bleaching
  • As biomes move, migration and behaviour patterns also change
    • Animals will have to migrate longer distances to find cooler climates, reduced pests, diseases and predators so they can breed 
    • Fish species are already moving further north and south of their usual habitats 
    • Reduced hibernation time due to warmer winters
    • Migrations begin earlier every year, with the birds leaving their winter nesting sites and heading north for the summer
  • Soil erosion reduces the fertility of the remaining soil
  • Soil erosion increases when rainfall is higher and vegetation is low
  • Warmer temperatures and increased rainfall increase soil loss on slopes
  • Increased rates of drought slow plant growth, reduce carbon cycling and reduce nutrient transfer to the soil; lack of nutrients and water exposes soil erosion; soil erosion can lead to desertification
  • Agricultural practices expose soil to increased run-off and erosion
    • Overgrazing: grazing animals destroy vegetation that binds soil particles
    • Over-cultivation: soil becomes exhausted
    • Deforestation: loss of roots to bind the soil 

Examiner Tip

It's important to note that while some regions may experience certain benefits from climate change, such as increased agricultural productivity or longer growing seasons, the overall negative impacts tend to outweigh the positive ones.

Changes on Agriculture

  • Suitable areas for agriculture will change
    • Farmers may have to change their crops 
    • Areas that could grow certain crops will have to change
      • Wheat grown in the USA will have to be grown in Canada
      • This will affect the USA's economy while boosting Canada's
  • Coastal flooding may lead to salt intrusion
  • Water shortages affect irrigation, limiting the choice of crops that can be grown
  • Food shortages will lead to malnutrition and famine
    • A rise of 3°C would reduce crop yields by 35% across Africa and the Middle East
    • A 2°C rise would cause 200 million people globally to experience hunger

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Jacque Cartwright

Author: Jacque Cartwright

Expertise: Geography Content Creator

Jacque graduated from the Open University with a BSc in Environmental Science and Geography before doing her PGCE with the University of St David’s, Swansea. Teaching is her passion and has taught across a wide range of specifications – GCSE/IGCSE and IB but particularly loves teaching the A-level Geography. For the last 5 years Jacque has been teaching online for international schools, and she knows what is needed to pass those pesky geography exams.