Global Warming Prediction Error: January 2013

There continues to be many news outlets that are pushing the idea that the Earth will warm up 4 °C by the year 2100.  Back in December I initially addressed the issue here, but a thought has percolated with me about how to really deal with this propaganda.  The idea is simple enough, I am going to start tracking the prediction error that exists from the warming that will have to take place in order to reach 4 °C of warming by the year 2100.  This is a way to see how realistic the projections for the next 87 years are.

To do this I had to pick a starting point.  Since 2100 is a nice arbitrary point in the future, I picked January 1, 2000 as my arbitrary starting point for tracking the error.  That gives the warmists 100 years for the Earth to warm up 4 °C.  1999 and 2000 both had very similar temperatures so using 2000 as the starting point for the error monitoring is also useful.

The error I will be measuring is the difference between the actual measured temperature (UAH is the one I will be using) and the predicted temperature.  So a negative error means the Earth is cooler than predicted.


A trend down in the error indicates that the prediction is wrong because the Earth is not warming.

A trend up in the error indicates that the prediction is wrong because the Earth is warming faster than predicted.

No trend in the error indicates that the predictions are correct.


One particular note.  Back in December I made the assumption that the NH and SH would not warm the same amount.  When I initially set this up it was apparent that this assumption drove a huge difference in the NH and SH.  As a result I have instead proceeded forward using the notion that both the NH and SH will have 4 °C of warming by the year 2100.  I still believe this is incorrect, but I will use that as the basis for the prediction because the error for the NH is so insanely absurd in the lack of warming.  The error is still substantial, but the difference between the hemispheres is greatly reduced.

The following chart is the basis for the prediction.  It assumes that the global anomaly will be 4 °C warmer in 2100 than it was in 2000.  In the year 2000 the Earth’s actual temperature was right at 14 °C.  So the Earth must be at 18 °C in the year 2100.  Anyone who thinks that will happen believes in global warming.  In order for the Earth to be 18 °C in the year 2100, the following warming must take place, although I will be the first to acknowledge that the Earth doesn’t behave linearly.


The Inconvenient Skeptic

(Purple) Global Temperature Anomaly, (Black) Actual Global Temperature to the year 2100.


Since I started in 2000, I now have 12 complete years in which to calculate the error.  I will be showing the error for the Earth as a whole and for each hemisphere individually.  All rates will be in °C/month.  So multiplying the rate by 120 will give the error/decade.  For instance the linear rates to get 4 °C warming in a 100 year period is:

0.0033 °C / month   =  

0.04 °C / year  =  

0.4 °C / decade  =  

4 °C / century

Since the regressions are based on the monthly data, the slope will be comparable to the °C / month.


The Inconvenient Skeptic



The Inconvenient Skeptic



The Inconvenient Skeptic


The global, NH and SH errors are all negative indicating that we are not on track to hit 4 °C by the year 2100.  If the current trend continues, the temperature in the year 2100 will be:


Global Anomaly:  1.0 °C

NH Anomaly:        1.4 °C

SH Anomaly:        0.6  °C


The Earth is currently not on track for the predictions to be correct.

Posted in Prediction Error by inconvenientskeptic on February 24th, 2013 at 11:43 pm.



This post has 4 comments

  1. We are already 13% into the 21st century and the predicted warming is 100% wrong. Warming up to now is 0C.

  2. inconvenientskeptic Feb 25th 2013


    No warming so far, but I think looking at the growing error in what it will take to warm up 4 °C is a nice new way to look at things. 🙂

  3. Johnny Feb 27th 2013

    Hello John,
    In your book, do you discuss the ozone layer? How ozone is formed? Or related subject matter in regard to ozone and it’s supposed effect on supposed global warming?… I have been attempting to understand the relationship between ozone, other particles and gases that interact with each other in the different atmospheres… I do not have a scientific background, nor would I say that my mind is geared toward an easy understanding of science in general… My understanding is that ozone is formed by ultra violet light hitting oxygen. And therefore how can ozone be depleting if oxygen isn’t? Unless there is no ultra violet light rays… As you can see I have a rudimentary understanding, and I’m not sure how everything else reacts with this process (given that I’ve actually got the process right in the first place!)… If you could steer me in the direction of some unbiased research, I would much appreciate it.
    kind regards,

  4. Joe Prins Mar 6th 2013

    Thanks for the above. What I also would be interested in is the rate of warming required from the present till 2100 in order to get to the Mythical 4 C increase. Using actual temperatures in graphic form would perhaps increase understanding. Especially for local newspaper reporter(s).

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