The headlines shout, "Scientists give strongest climate change warning" and "Grim message on climate change".
Yes the just-released Fifth Assessment of the UN's Intergovernmental Panel on Climate Change (IPCC) declares the science more certain than ever. It wasn't always so.
The IPCC's First Assessment in 1990 was equivocal. "The observed increase could be largely due to natural variability."
The 1996 Second Assessment was more certain. "The balance of the evidence suggests a discernible human influence on climate."
The 2001 Third Assessment declared the evidence strong: "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities".
The 2007 Fourth Assessment declared it 90 per cent probable that humans were to blame. "Most of the observed increase in globally averaged temperature since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations."
And now the just-released 2013 Fifth Assessment declares that "It is extremely likely [that is, 95 per cent probable] that human influence has been the dominant cause of the observed warming since the mid-20th century".
The IPCC has become more and more certain with each Assessment.
And with each Assessment the outlook has got gloomier and gloomier. That's because their computer models show greenhouse gases forcing temperatures to dangerous levels in the not-too-distant future.
As a result, governments have spent billions trying to restrict greenhouse gas emissions. All to no avail. The Fifth Assessment tells us that greenhouse gases are at an 800,000 year high.
But the news is not all bad. The hike in temperatures has "paused" despite the continued hike in greenhouse gases. The IPCC had been almost 95 per cent certain the world would now be warmer than it actually is. Their predictions haven't proved true.
Indeed, the evidence supporting the idea that humans are causing dangerous warming has got less with each assessment.
By the time of the Third Assessment the warming trend had stopped. There had been no discernible warming for nine years by the time of the Fourth Assessment. And now there's been none for 15 years.
The Fifth Assessment in draft admitted that the models had failed. "Models do not generally reproduce the observed reduction in surface warming trend over the last 10-15 years."
But that admission was edited out. Instead, the Assessment excused the failure: "Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends".
So there you have it. More and more certain. Less and less evidence.
The IPCC's disconnect from reality has left me 85 per cent certain in my diagnosis: the IPCC's psychotic.
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