Human Impact on the Environment (WJEC GCSE Biology: Combined Science)

Revision Note

Naomi H

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Naomi H

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Biology

Conflict between Human Need & Conservation

  • A rapidly increasing human population means that the human need for resources continues to increase, e.g.
    • More agriculture is needed to ensure that enough food is produced
    • Land requirements for housing are increasing
    • Industry requires more land and energy and also produces more pollution
  • The increased need for resources means that human requirements are often in conflict with the needs of other species

Environmental impact assessments

  • Proposed developments, e.g. housing or industrial buildings, can only go ahead once an environmental impact assessment has been completed 
    • During an environmental impact assessment, biologists study the proposed development site to identify local species and determine the value of the site to wildlife
      • Endangered or protected species might be found, e.g. great crested newts
      • Important sites, such as maternity bat roosts, might be present
    • The assessment will determine the effects of a particular development on local wildlife and will put forward solutions to reduce its impact
  • The findings of an assessment may mean that:
    • Developers need to modify their plans to protect certain endangered species, e.g. relocating newts to another local pond
    • Developers are granted permission under certain conditions, e.g. they may be asked to plant more trees, or build new habitats for displaced species
    • Permission may be refused if environmental damage cannot be mitigated
Two great crested newts

Bouke ten Cate, CC BY-SA 4.0, via Wikimedia Commons

An environmental impact assessment may be carried out to determine whether great crested newts are present on a proposed development site; if they are found then developers would be expected to protect them

Government agencies

  • In addition to environmental impact assessments, which are often carried out by biologists working for private companies, there are government agencies tasked with reducing the impact of human activities on the environment, e.g.
    • The Environment Agency
      • Involved with ensuring that development is carried out in a sustainable way
      • Has responsibility for waste management

Intensive Farming Methods

  • In order to produce enough food to feed a growing human population, some farmers are turning to more intensive farming methods
  • Intensive farming aims to produce more food with reduced energy and land inputs

Advantages and disadvantages of intensive farming table

Farming method Advantages Disadvantages
Agricultural machinery

Allows farmers to farm larger areas of land easily

Machinery can monitor crop health more effectively, reducing losses to disease and ensuring that harvesting is carried out at the correct time; this results in increased yields

May take jobs away from people

Machinery usually runs on fossil fuels

Smaller fields may need to be combined into larger fields, resulting in losses of hedgerow habitats
Chemical fertilisers Increases soil nutrient availability, leading to larger crop yields Fertilisers can run off into local bodies of water, leading to eutrophication
Insecticides and herbicides Kills insect pests and reduces competition from weeds, leading to larger crop yields

May kill non-target species

May lead to the evolution of pesticide and herbicide resistance
Selective breeding of crop and animal species Can be used to produce food varieties that are resistant to environmental damage, have a higher yield, and taste better

Such varieties are often grown as monocultures, reducing biodiversity

Selectively bred varieties may have low genetic variation, reducing their ability to adapt to change

Disease control Antibiotics may be used to prevent disease in livestock populations; this reduces losses due to disease and leads to increased meat production

Overuse of antibiotics can increase the likelihood of antibiotic-resistant strains emerging

Antibiotics may be present in meat
Battery farming of livestock Livestock live in small, temperature controlled spaces, reducing energy losses due to movement and temperature regulation; this means that more energy is used in growth and meat production increases

Many have concerns about the welfare of animals farmed in this way

Disease can spread easily, leading to the loss of many animals at the same time; this can be expensive for farmers

 

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Naomi H

Author: Naomi H

Naomi graduated from the University of Oxford with a degree in Biological Sciences. She has 8 years of classroom experience teaching Key Stage 3 up to A-Level biology, and is currently a tutor and A-Level examiner. Naomi especially enjoys creating resources that enable students to build a solid understanding of subject content, while also connecting their knowledge with biology’s exciting, real-world applications.