Contentious Issues in Environmental Science (Edexcel International A Level Biology): Revision Note

Contentious Issues in Environmental Science

• It can be said that there is a consensus, i.e. everyone agrees, among the scientific community that

  • Increasing concentrations of greenhouse gases cause global warming

  • Human activities are the direct cause of increasing greenhouse gas concentrations

• Despite this there are some individuals, even among the scientific community, who do not believe that the correlation seen between humans burning fossil fuels and global warming is a causal relationship

  • These individuals claim that global warming is caused by factors other than human activities

Evaluating the data

• It is important to evaluate any statement that is made about the causes of climate change in the light of scientific evidence

  • Consider how good the evidence is

    • Does a statement address all of the evidence, or only part of it?

      • E.g. there may be some years when global temperatures go down, but there is strong evidence for an overall upward trend

    • Is the data reliable?

    • Does the data come from several independent studies i.e. is there plenty of evidence?

    • Does statistical analysis show that findings are statistically significant?

  • Find out whether the statement comes from a trustworthy, unbiased source e.g.

    • An individual working for an oil company or a particular government is likely to be biased because they have a financial or political interest in the outcome of a study 

      • Several countries wrote to the United Nations in 2021 to ask that urgent recommendations against burning fossil fuels were toned down; all of these countries had economies that depended on the use of fossil fuels

    • An individual who campaigns passionately for conservation may be biased because they strongly believe that humans are causing climate change and they have an emotional stake in the outcome of a study

    • An individual who works for a renewable energy company may be biased because they are of the opinion that their technologies are better than fossil fuel technologies as well as having a financial interest in the outcome of a study

Evaluating Claims that Human Activities are not the Cause of Cimate Change Table

• When claims are made about the causes of climate change, it is important to evaluate these claims while bearing the following factors in mind

  • There is a great deal of scientific evidence that has been tested and checked by other scientists that supports the hypothesis that humans burning fossil fuels causes climate change; this increases the likelihood that further claims of this nature are correct

  • Climate is highly complex, so scientists need to be careful not to state that one factor alone has led to a specific event

    • Climate can be affected by any number of factors in any given year; it is important to look at all of the data

      • Climate and weather experts in the media are often asked about whether one particular extreme weather event is due to climate change; they always say that it is wrong to draw conclusions from one event, while also pointing to that event's place in a trend of increasingly extreme weather

    • Climate change is not expected to be linear in effect; scientists expect that there may be a tipping point beyond which changes happen faster

      • This makes it very difficult to make predictions about exact future climate conditions

  • People may have a personal interest; some are especially passionate about the environment, while others depend financially on fossil fuels

    • It is important that we are aware of the personal biases of those making claims about the causes of climate change

• If predictions about global warming are correct, then the potential impacts on the future of Earth are huge

• As scientists, it is our responsibility to be aware of the important factors surrounding this debate so that we can help other to assess evidence thoroughly