The Independent reports on a new paper about the likelihood of a climatic tipping point being reached by 2200. How did they achieve this? Have they come up with a new wonder-model? Or by achieving a fundamental refinement of the existing models? No, the answer is more mundane. They interviewed 14 leading scientists on climate change, asking them some sophisticated (but leading) questions. It is an opinion poll, with a biased and insignificant sample. But it is revealing about the quality of climate change “science”.
For instance consider the following from the abstract.
“The width and median values of the probability distributions elicited from the different experts for future global mean temperature change under the specified forcing trajectories vary considerably.”
I thought statistical results could only come from statistical analysis, not experts reviewing the literature.
“For a forcing trajectory that stabilized at 7 Wm-2 in 2200, 13 of the 14 experts judged the probability that the climate system would undergo, or be irrevocably committed to, a “basic state change” as ≥0.5.”
In science, a probability can only be calculated from the data, and can be subjected to a battery of tests for robustness. In common parlance probabilities are used as an expression of opinion. Like the IPCC forecasts for temperature the distinction is blurred. In this case it appears to be the latter, so should be clearly stated as such in a scientific journal.
A second problem is the forcing trajectory being stabilised at 7 Wm-2. That is on top of the existing 324 Wm-2, a 2% rise (See IPCC AR4 page 96). The current greenhouse effect makes average global temperatures of 14oC up to 33oC higher than they would have otherwise been. If the effect were a linear one, then I would expect this impact to be 0.7oC. However I would expect the relationship to be a non-linear, with a diminishing marginal impact for each successive increase in the greenhouse forcings. To get to the median IPCC predicted increase of 3.5oC for this century would require huge increasing impact. Maybe climatologists are too lost in their consensus to see the bigger picture provided by data analysis.
“Finally, most experts anticipated that over the next 20 years research will be able to achieve only modest reductions in their degree of uncertainty.”
Do you want some accurate, scientific, analysis of the climatic instability that will be brought about by rising temperatures, in turn caused by rising CO2? The best experts cannot see this being achieved until long after they retired.
The Real Conclusion
The top climate scientists tacitly acknowledge that there is no robust, scientific basis for the climatic instability forecast.
Hat tip: Richard North at EU Referendum