“How to lie with statistics”, an example

Climate Change: Atmospheric Carbon Dioxide

“The global average atmospheric carbon dioxide in 2018 was 407.4 parts per million (ppm for short), with a range of uncertainty of plus or minus 0.1 ppm. Carbon dioxide levels today are higher than at any point in at least the past 800,000 years.

Source: NOAA Climate.gov

This chart accompanies the claim(numbered red boxes added):


Statistical fallacies employed:

  1. “Correlation is not causation”:
    CO2 levels are interesting but correlation may be coincidental or the cause-effect relationship might be the reverse, i.e. temperature might cause CO2 to increase. The Climate system is complex and there are other significant variables influencing global temperature, atmospheric water vapour for instance and Milankovitch cycles.
  2. “Cherry-picking data”:
    The chart of the last 600 million years (below) shows that today’s CO2 levels are low relative to levels the longer timeframe.
  3. “Omitting the baseline”
    The Y-axis starts at 150. This is a case of “Graph manipulation”
  4. “Amplifying the Y-axis”.
    For the period which is cherry-picked, the maximum is 400 ppm (that is 0.04% of the atmosphere). CO2 levels have been 10 times that concentration in earth’s history.

The following chart:

  1. Shows both Temperature and CO2 levels.
    If there is any correlation, it isn’t obvious.
  2. There appears to be correlation for the most recent 50m years – but that could be coincidental
  3. The baseline is zero for CO2
  4. Showing the full range of CO2 levels (up to 7000 ppm), today’s levels of 400 ppm are not high

Source: JoNova

The 800,000 years shown in the first chart is about 1.3% of the Tertiary period at the right, less than 1 pixel width of the above chart.

The Corals which are supposedly jeopardised by ‘Climate Change’ survived 543m years, or most of the above chart. Thanks, JoNova!