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

• 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