Climate Change Damage Impacts – A story embellished at every retelling

Willis Eschenbach has a posting on a recent paper on climate change damage impacts. This is my comment, with hyperlinks and tables.

My first reaction was “Oi– they have copied my idea!”

Well the damage function at least!

Actually, this can be found by the claims of the Stern Review or AR4. Try looking at the table in AR4 of “Examples of impacts associated with global average temperature change” and you will get the idea.

A simpler, but more visual, perspective is gained from a slide produced for the launch of the Stern Review.

More seriously Willis, this is worse than you thought. The paper makes the claim that unlikely but high impact events should be considered. The argument is that the likelihood and impacts of potential catastrophes are both higher than previous thought. The paper then states

“Various tipping points can be envisaged (Lenton et al., 2008; Kriegler et al., 2009), which would lead to severe sudden damages. Furthermore, the consequent political or community responses could be even more serious.”

Both of these papers are available online at PNAS. The Lenton paper consisted of a group of academics specialising in catastrophic tipping points getting together for a retreat in Berlin. They concluded that these tipping points needed to include “political time horizons”, “ethical time horizons”, and where a “A significant number of people care about the fate of (a)

component”. That is, there is a host of non-scientific reasons for exaggerating the extent and the likelihood of potential events.

The Krieger paper says “We have elicited subjective probability intervals for the occurrence of such major changes under global warming from 43 scientists.” Is anybody willing to assess if the subjective probability intervals might deviate from objective probability intervals, and in which direction.

So the “Climate Change damage impacts” paper takes two embellished tipping points papers and adds “…the consequent political or community responses could be even more serious.”

There is something else you need to add into the probability equation. The paper assumes the central estimate of temperature rise from a doubling of CO2 levels is 2.8 degrees centigrade. This is only as a result of strong positive feedbacks. Many will have seen the recent discussions at Climateaudit and wattsupwiththat about the Spencer & Bracewell, Lindzen and Choi and Dessler papers. Even if Dessler is given the benefit of the doubt on this, the evidence for strong positive feedbacks is very weak indeed.

In conclusion, the most charitable view is that this paper takes an exaggerated view (both magnitude and likelihood) of a couple of papers with exaggerated views (both magnitude and likelihood), all subject to the occurrence of a temperature rise for which there is no robust empirical evidence.

Royal Society lacks rigor in 20% cuts hypothesis

The New Scientist reports that the Royal Society believes that a “20 per cent cuts to British science means ‘game over’”. (Hattip BishopHill)

In the article, some of the scientists point to the need for innovation to promote the high-tech industries on which our recovery depends. I quite agree. However, I would profoundly disagree that government-funded research science is the best way to achieve this. Firstly, because government-funded research is notoriously bad at producing the job-creating outputs. In fact, the public sector tends to specialise in pure research, with only distant business opportunities. Second, is that government-funded research tends to be long-term. Most politicians would agree that currently we need the new jobs in the next few months, not a decade or more down the line.

As an aside, the idea that a 20% cut “would cause irreversible destruction” is a hypothesis that should be expounded in a more rigorous & scientific manner, with empirical evidence to back this up. I believe that it is analogous to the notion of tipping-points in climate science, so the Royal Society would do well to exchange notes with the folks at the Climate Research Unit at UEA. In trying to model their separate issues they will find that positing of such turning points relies on disregarding the real-world background “noise”. Such “noise” renders the turning points both unpredictable and highly unlikely.

My counter-argument is that, historically, Britain has been very good at the creative elements of pure science and invention. We are not so good at turning that into the reliable world-beating products that create the jobs. We are the country of Newton, Marconi, Whittle and Turing. We are not the country of Apple, Toyota, Nokia, Siemens or BMW.

Climate Tipping Points – The Real Conclusion beneath Scientists Opinion

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.


Quote 1

“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.


Quote 2

“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.


Quote 3

“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