Shock! Prediction about global warming made in 1999 stunningly accurate

1999 prediction black line; actual temperatures red line; yellow diamonds individual years

In a paper just published  Nature Geoscience titled Test of a decadal climate forecast (doi:10.1038/ngeo1788) forecasts made in a climate models form 1999 have been  accurate within a “few hundreds of a degree”.

As the Guardian reports:

The paper, published on Wednesday in the journal Nature Geoscience, explores the performance of a climate forecast based on data up to 1996 by comparing it with the actual temperatures observed since. The results show that scientists accurately predicted the warming experienced in the past decade, relative to the decade to 1996, to within a few hundredths of a degree. 

The forecast, published in 1999 by Myles Allen and colleagues at Oxford University, was one of the first to combine complex computer simulations of the climate system with adjustments based on historical observations to produce both a most likely global mean warming and a range of uncertainty. It predicted that the decade ending in December 2012 would be a quarter of degree warmer than the decade ending in August 1996 – and this proved almost precisely correct. 

The study is the first of its kind because reviewing a climate forecast meaningfully requires at least 15 years of observations to compare against. Assessments based on shorter periods are prone to being misleading due to natural short-term variability in the climate.

So, scientists created a complex computer simulation in 1999; it has proven to be stunningly accurate.

I can’t wait to see how the denial machine will spin that one.

31 thoughts on “Shock! Prediction about global warming made in 1999 stunningly accurate

  1. Steve says:

    It’s a pity you have to pay to read the paper. I would be interested to know if the authors have now made a prediction for another decade.

    • Watching the Deniers says:

      Agree, pay walls make it hard for the general public. I’ve got my hands on a copy so will post more.

  2. john byatt says:

    Gavin Schmidt , last year

    • The continuation of the linear trend from August 1975 to July 1997 would have predicted a temperature anomaly in August 2012 of 0.524ºC

    . The actual temperature anomaly in August 2012 was 0.525ºC.


  3. It’s amazing how accurately they were able to predict the trend from 1950 through 1998 given that they were handicapped by having to make the prediction in 1999.

    I myself am considering putting out a paper on lottery number predictions. I plan to predict the correct winners from 2002 through 2012 and then sell my “system” at $1,000 a shot to any who’d like to buy it and make gazillions.

    Any takers here?


  4. roymustard says:

    Astonishing and, I must point out, far more accurate than any “skeptical” prediction whose forecasts are always coloured by the personal belief that it simply must start cooling soon. Sadly, this vaunted cooling/ice age never occurs.

  5. […] the IPCC (revealing political motive) and climate models (which, as Watching The Deniers show, are far more accurate than his […]

  6. john byatt says:

    for ice age is here” twits, turn graph upside down.

  7. john byatt says:

    Over at Sou’s place

    Watts ” We built on the flaws of the first work,”

    without comment

  8. 2012 and all that says:

    Scary and it puts all the accusations of “alarmism” into context.

  9. […] accurate | Environment |…tml#affil-auth Shock! Prediction about global warming made in 1999 stunningly accurate | Watching the Deniers Assuming this paper stands scrutiny (currently pay-walled), it is quite impressive. I would not […]

  10. toby52 says:

    If you have a copy of the paper, can you check how they handled climate sensitivity? given recent “debate” that is of interest.

  11. klem says:

    Wow the accuracy of that accurate prediction is so accurate it’s just uncannily accurate.

    Um, this begs the question, what about the accuracy of the other 5000 predictions made back in 2009?

    Oh…Perhaps we’ll just sweep those other predictions under the rug…there… all gone..


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