How to Lie With Statistics

Estimated Temperatures During A and E TimesSteve McIntyre of Climate Audit caught Professor Michael Mann of hockey stick fame misleading people about the quality of global climate models at the December 2012 American Geophysical Union meeting.

A problem for those who are convinced that mankind’s activities are influencing global temperature is that, as the top chart from the IPCC shows, recent observations of land-and-ocean temperature (red line) are considerably lower than midrange temperature model predictions (blue line). [The red and blue lines were added by McIntyre to aid in discussing the chart.] In fact, as previously reported at this blog, there has been no warming for the past 15 years.

Land-and-OceanThe second chart is a bad photo of one that Mann used in his talk with, once again, the red and blue lines added by McIntyre for emphasis. Two tricks minimize the difference between observation and predicted temperatures. First, this graph plots land temperatures (red line) which are always warmer than land-and-ocean temperatures. The Climate Audit site has an animated graphic showing just how much they differ. It also offers additional photos, and a clearer chart showing that similar data manipulation was used at an earlier talk at Rugters.

Second, the graph only provides temperature data to 2005 even though the talk occurred in 2012.

The result is a slide that made it look like observed temperatures agree with the models that forecast global warming, a result not supported by the IPCC graph.

Comments (8)

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  1. Tom says:

    Manipulating statistics has been seen over and over again on a wide range of topics and fields. Sad how far people go to fulfill special interests.

  2. Ryan says:

    @Tom: True, statistics are often manipulated and oftentimes the general policymaker can’t even read data and will tend to believe such reports. Therefore, oftentimes policies can be implemented based on false data. I think this issue permeates beyond statistics, however.

  3. Tyson says:

    I’ve learned that stats can pretty much be manipulated to fit any kind agenda, conservative or liberal.

  4. Kimberly says:

    To all of comments above: I agree.

  5. Samson says:

    I guess the saying “numbers dont lie” isn’t always true?

  6. Gabriel Odom says:

    We actual statisticians sit in the heavens and laugh.

  7. H. James Prince says:

    I would like to say that I am shocked and appalled by this, but I’m only appalled.

  8. Henry GrosJean says:

    These graphs don’t make sense. Make them simpler. I don’t want to have to think about these things.