Another attempt to deny the significance of the warming "pause"
What a crock! They found that the models gave reasonable predictions of weather in the past and say that the models are therefore right despite the "pause". But all or almost all of the models have been adjusted at some stage to give accurate hindcasts. So all that the study below shows is that the modellers have done a good job of getting their models to give good hindcasts. Forecasts defeat them, however
The temperature of Earth's surface has increased by only 0.06°C in the past 15 years - a fact that contradicts global warming climate models. This so-called 'pause' has been used by some groups as evidence by that climate change is not taking place.
Now a new study suggests that the discrepancy between the models and reality is all down to random fluctuations in the Earth's climate – and that the long-term trend still points to severe warming.
Researchers at Max Planck Institute for Meteorology in Hamburg and Leeds University in the UK say the models do not overestimate man-made climate change.
They claim global warming is 'highly likely' to reach critical proportions by the end of the century - if the global community does not finally get to grips with the problem.
The global average temperature has risen only slightly since 1998 – which is surprising, considering scientific climate models predicted considerable warming due to rising greenhouse gas emissions.
To explain the discrepancy between model simulations and observations, Professor Marotzke and Piers Forster compared simulated and observed temperature trends over all 15-year periods since the start of the 20th century.
For each year between 1900 and 2012 they looked at the temperature trend that each of the 114 available models predicted for the subsequent 15 years.
They then compared the results with measurements of how the temperature actually rose or fell.
By simulating the average global temperature and other climatic variables of the past and comparing the results with observations, they were able to check the reliability of their models.
The 114 model calculations withstood the comparison. 'On the whole, the simulated trends agree with the observations,' said Professor Marotzke.
'The most pessimistic and most optimistic predictions of warming in the 15 subsequent years for each given year usually differed by around 0.3 degrees Celsius.
'However, the majority of the models predicted a temperature rise roughly midway between the two extremes.
'The observed trends are sometimes at the upper limit, sometimes at the lower limit, and often in the middle, so that, taken together, the simulations appear plausible.
'In particular, the observed trends are not skewed in any discernible way compared to the simulations,' Professor Marotzke explains.
If that were the case, he said, it would suggest a systematic error in the models.
The scientists are now also analysing why the simulations arrived at disparate results by looking at how the models react to increases in atmospheric carbon dioxide.
Since 1998, the warmest year on record, the steep increase in global temperatures seen during the 1990s has levelled off, failing to match computer model predictions for climate change.
This pause, or hiatus, has been blamed on weak solar activity and increased uptake of heat by the world's oceans.
The UN's Intergovernmental Panel on Climate Change last year concluded that the deep oceans had been responsible for absorbing an increasing amount of heat, but warned that this could not continue indefinitely.