in which he examines a paper by Smith et al (2007)
In 2007, a team of climate scientists from the UK Met Office led by Doug Smith wrote a paper “Improved Surface Temperature Prediction for the Coming Decade from a Global Climate Model”, published in the journal Science. Although published in 2007, the paper made predictions for the decade 2004-2014. (Presumably the work was started around 2004 and it took some time for the paper to be published). The paper made claims about the “skill” of the model, for example “Having established the predictive skill of DePreSys…”
The Smith et al paper made the following specific predictions:As we come to the end of 2013 we have only a year to go to see whether the 0.3ºC warming over the decade will eventuate.
- There would be 0.3°C warming over the decade 2004-2014
Note that at that time, 2007, the warmest year was thought to be 1998; subsequent adjustments to the method made 2005 warmer than 1998.
- At least half of the years after 2009 would be warmer than the record year of 1998.
Using the (UN)Skeptical Science trend calculator we find for the period 2004 to date the major data sets show
- GISS - 0.009±0.248ºC per decade
- NOAA - -0.019±0.226ºC per decade
- HadCRUT4 -0.030±0.225ºC per decade
- Best 0.075±0.651ºC per decade
- NOAA -0.001±0.400ºC per decade
- RSS -0.022±0.418ºC per decade
- UAH 0.063±0.431ºC per decade
Four out of seven show a negative trend and the three positives are nowhere near the 0.3ºC predicted by Smith et al.
2014 will have to be Hell on Earth for their prediction to be realised.
For More of Paul Matthew's post go to The Skilful Prediction of Climate Science