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Environmental Management AS CIE

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  1. 1-1-continents-and-oceans as
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  2. 1-2-country-classification-by-income-level as
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  3. 1-3-sustainability as
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  4. 1-4-the-water-cycle as
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  5. 1-5-the-structure-and-composition-of-the-atmosphere as
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  6. 1-6-ecosystems as
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  7. 2-1-the-scientific-method as
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  8. 2-2-environmental-research-in-the-context-of-climate-change as
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  9. 2-3-collection-of-environmental-data as
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  10. 2-4-data-collection-techniques-and-data-analysis as
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  11. 2-5-the-use-of-technology-in-data-collection-and-analysis as
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  12. 3-1-human-population-dynamics-and-structure as
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  13. 3-2-impacts-of-human-population-change as
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  14. 3-3-managing-human-population-change as
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  15. 4-1-ecosystems as
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  16. 4-2-managing-the-conservation-of-biodiversity as
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  17. 4-3-impacts-of-human-activity-on-ecosystems as
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  18. 5-1-food-security as
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  19. 5-2-energy-resources as
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  20. 5-3-waste-management as
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  21. 6-1-global-water-distribution as
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  22. 7-1-acid-deposition as
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  23. 7-2-photochemical-smog as
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  24. 7-3-managing-air-pollution as
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  25. 7-4-ozone-depletion as
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  26. 8-1-climate-change as
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  27. 8-2-the-impacts-of-climate-change as
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Exam code:8291

Observations & Hypotheses

  • The scientific method is a systematic approach used by scientists to investigate natural phenomena and acquire knowledge

    • Central to the method is the interplay between observations and the development, testing, and evaluation of hypotheses

  • Observations involve gathering information using the senses or scientific tools and instruments

    • Observations serve as a starting point, prompting scientists to explore and understand a particular phenomenon

  • Hypotheses are educated guesses or predictions that are formulated based on observations

    • Scientists use inductive reasoning to generate hypotheses from observed patterns or phenomena

  • Scientists continually refine their hypotheses through a cyclical process of observation and hypothesis formulation

    • Observations guide the formation of hypotheses, and hypotheses, in turn, prompt further observations

Flow chart outlining the scientific process
The scientific method follows a standardised process, as shown by this flow chart

  • In summary, the main steps of the scientific method are:

    1. Make an observation (or note a phenomenon in the natural world) that poses a problem or question

    2. Develop a testable hypothesis based on the observed patterns or phenomena

    3. Design an experiment that allows for controlled variables and quantitative data collection

    4. Conduct the experiment and gather quantitative data to objectively measure the outcomes

    5. Use statistical methods to analyse the collected data and draw meaningful conclusions

    6. Make a conclusion by evaluating whether the results support or do not support the hypothesis, leading to a clearer understanding of the phenomenon

  • It is possible to apply the scientific method to design and conduct investigations focused on environmental issues, ensuring the collection of reliable environmental data

    • This data can be used to help further our understanding of environmental challenges and how to manage them

Testing a Hypothesis

  • When scientists want to explore and understand something, they conduct experiments to test their ideas

    • This process is known as hypothesis testing, a crucial step in the scientific method

  • In order for an experiment to produce valid quantitative data (that can then be analysed), there are certain types of variables that need to be understood and carefully managed

Variables

  • In an experiment, a variable is any factor that can change or be changed

  • There are different types of variables within an experiment

    • The independent variable: the only variable that should be changed throughout an experiment

    • The dependent variable: the variable that is measured to determine the outcome of an experiment (the results)

    • The controlled variables: any other variables that may affect the results of the experiment that need to be controlled (if possible) or monitored

  • It is essential that any variable that may affect the outcome of an experiment is controlled in order for the results to be valid and for the experiment to be considered a fair test

    • A fair test is one in which only the independent variable has been allowed to affect the dependent variable

    • Preliminary research and preliminary studies can be used to identify variables within an experiment and to determine ways of controlling these variables effectively

    • The existing published scientific research surrounding the question or problem being investigated is likely to contain information about different factors or variables that the person doing the experiment should be aware of

Examples of Independent and Dependent Variables

Experiment

Independent Variable

Dependent Variable

Example of Control Group

Impact of soil pH on plant growth

Soil pH

Height and health of the plants

Plants in soil with a carefully maintained neutral pH

Effect of temperature on fish behaviour

Water temperature

Fish swimming patterns and activity

Fish in a controlled tank with a consistent, optimal temperature

Influence of light intensity on photosynthesis

Light intensity

Rate of photosynthesis in plants

Plants exposed to a controlled, consistent low light environment

Study on air pollution impact on respiratory health

Air pollution levels

Respiratory health of study participants

Individuals in an area with minimal air pollution exposure

Biodiversity in response to habitat fragmentation

Level of habitat fragmentation

Diversity and abundance of species

Ecosystem with undisturbed, unfragmented habitat

Impact of fertiliser type on crop yield

Type of fertiliser used

Crop yield and quality

Crops treated with a standardised, common fertiliser or no fertiliser

  • The effect of temperature on photosynthesis can be investigated as shown in the diagram below

    • The plants usually used are Elodea or Cabomba – types of pondweed

    • As photosynthesis occurs, oxygen gas produced is released 

    • As the plant is in water, the oxygen released can be seen as bubbles leaving the cut end of the pondweed

    • The number of bubbles produced over a minute can be counted to record the rate

    • The more bubbles produced per minute, the faster the rate of photosynthesis

Diagram showing how to investigate the effect of changing temperature on the rate of photosynthesis in pond weed
Investigating the effect of changing temperature on the rate of photosynthesis – note the independent variable (IV), dependent variable (DV) and controlled variables (CV)

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