In Part I of the series, we discovered that the International Panel on Climate Change (IPCC), in its 2007 Summary Report, scientifically considered certain uncertainties within its assessment, but they failed to do so in a comprehensive way.

Al Gore’s conclusion that We Must Act Now! depends on all three of the following being True:

• Premise A: the earth is warming
• Premise B: mankind is the cause
• Premise C: we can effectively do something about it.

IPCC addresses the uncertainty of their judgment of each of these Premises. What they don’t address is the uncertainty of the confluence of all three, which according to the Laws of Probability is much less likely than one might perceive. In Part I, I showed that even IPCC’s “objective” uncertainty assessments of these Premises implies 1 chance in 4 that implementation of strategies to counter Global Warming is a waste.

In Part II, we’ll address how a rational and open-minded skeptic might assess the same uncertainty.

As for Premise A, we’ll be open-minded. Let’s assume it’s likely, not unequivocal, that there’s a warming trend. By IPCC’s uncertainty scale (see below):

P(A) = 66%

[Somewhat surprisingly, the IPCC asserts: "During the past 50 years, the sum of solar and volcanic forcings would likely have produced cooling [absent AGW].” (emphasis in original) Maybe Global Warming has been a good thing. But I digress…]

Premise B is less certain. I’m not sure whether atmospheric CO2 is a cause or an effect. Has Climate Change Theory adequately explained the non-anthropogenic Ice Ages, or more subtle climate changes in the historical period? Does computer modeling adequately describe the complexity of earth, ocean and atmospheric systems and their interactions? But since we’re being open-minded for this exercise, let’s be generous and say that it’s as likely as not that Global Warming is caused by manmade concentrations of GHGs. So,

P(B) = 50%

Premise C, which says that we can effectively adapt and/or mitigate the effects of Climate Change, is perhaps the most troubling of all. Buried in the IPCC’s Summary Report is this sentence that deserves a careful reading:

Limited and early analytical results from integrated analyses of the costs and benefits of mitigation indicate that they are broadly comparable in magnitude, but do not as yet permit an unambiguous determination of an emissions pathway or stabilisation level where benefits exceed costs.

Please allow me to translate: “We’ve tried and we’ve tried, but we haven’t yet found any strategies that even begin to make economic sense.” And that’s from scientists who take AGW as a given; they’re not even accounting for the chance that no strategy at all is needed because there’s no warming, or that they do not understand the true warming mechanism.

Then there’s this little chestnut:

Sustainable development can reduce vulnerability to climate change, and climate change could impede nations’ abilities to achieve sustainable development pathways. It is very likely that climate change can slow the pace of progress toward sustainable development either directly through increased exposure to adverse impacts or indirectly through erosion of the capacity to adapt. Over the next half-century, climate change could impede achievement of the Millennium Development Goals. [emphasis in original]

Translation: “If AGW Strategies Are Implemented, Women and Minorities Will Be Hardest Hit”. In the IPCC’s estimation, there is at least a 90% chance that the developed world will benefit from AGW solutions at the expense of the poorest nations, which lack the resources, technology and organization to keep up. The “Millennium Development Goals” are defined in the IPCC’s Glossary as “A set of time-bound and measurable goals for combating poverty, hunger, disease, illiteracy, discrimination against women and environmental degradation, agreed at the UN Millennium Summit in 2000.” Oh, well, since we’re only talking poverty, hunger, disease, illiteracy, discrimination against women and environmental degradation, surely Africa won’t mind a bit.

Reading between the lines, it appears that even the IPCC is quite uncertain as to the efficacy of any AGW remedies that might be employed. In playing doctor with Mother Gaia, it would serve us well to remember the physician’s admonition: “First, do no harm.” For the governments of the developed countries to waste economic resources on a solution absent a compelling economic benefit is foolish and immoral.

Despite all that, given our commitment to open-mindedness, let’s give ‘em the benefit of the doubt, and say it’s as likely as not that the remedies employed will be safe, efficient, and effective:

P(C) = 50%

Now we can evaluate our degree of certainty in the proposition that We Must Act Now! to Combat AGW !

66% x 50% x 50% = 16%

So, under this rather generous analysis, it’s 5 times as likely as not that any effort to combat Global Warming is a waste.

And that’s if we’re being an open-minded skeptic.

OK, Vladimir, so what do you really think?

Is there Global Warming? Heck if I know. A lot of bright scientists seem to think so, but there’s a lot of legitimate questions about sampling and methodology. And, as commenter Praying points out in an answer to Part I, an apparent cooling trend beginning in about 1997. I’ll take the chicken’s way out & say P(A) = 50%, a coin flip.

Is manmade CO2 the primary cause? I remain unconvinced. There’s a demonstratable warming mechanism, but earth systems are too complex, interrelated and chaotic to lend themselves to analysis by computer modeling. A computer model will always match history, but that lends no credence on the forecast as history matching gives a non-unique solution. And (again, as Praying has pointed out) there’s no attempt to explain climate history on the part of the Climate Change community. I’ve got a little formal and applied geology under my belt, and I work with 5 geoscientists, all of whom have advanced degrees, and all of whom are AGW skeptics. P(B) = 20% (at best).

Remedies? I think there’s every chance that “the cure may be worse than the disease”. I have yet to hear the Climate Change community state the conditions that would arise to make them rethink and back down from Climate Change remedies. I think it’s going to be expensive and have a negative benefit-to-cost ratio. Governments and NGOs always underestimate the costs of major projects (e.g., the “Big Dig”). I think the remedies are likely to harm the third world. I think that there are likely to be countries that will never cooperate (India and China), dooming a European/North American solution. I think the Big Government folks will effectively hamper the industrialized economies and the American consumer, but be powerless to deal with big, non-point-source polluters like the Indonesian peat fires. And I think the earth and the oceans are awfully, awfully big and nearly impossible to influence on purpose. P(C) = 5% or less.

So, on a good day, 50% x 20% x 5% = 0.5%

Half a percent. Using the IPCC scale, that rates as exceptionally unlikely. That pretty well sums up my position.

The IPCC’s nomenclature for uncertainty follows, from the IPCC’s Full Report for 2007:

Where uncertainty is assessed qualitatively, it is characterised by providing a relative sense of the amount and quality of evidence (that is, information from theory, observations or models indicating whether a belief or proposition is true or valid) and the degree of agreement (that is, the level of concurrence in the literature on a particular finding). This approach is used by WG III through a series of self-explanatory terms such as: high agreement, much evidence; high agreement, medium evidence; medium agreement, medium evidence; etc.

Where uncertainty is assessed more quantitatively using expert judgement of the correctness of underlying data, models or analyses, then the following scale of confidence levels is used to express the assessed chance of a finding being correct: very high confidence at least 9 out of 10; high confidence about 8 out of 10; medium confidence about 5 out of 10; low confidence about 2 out of 10; and very low confidence less than 1 out of 10.

Where uncertainty in specific outcomes is assessed using expert judgment and statistical analysis of a body of evidence (e.g. observations or model results), then the following likelihood ranges are used to express the assessed probability of occurrence: virtually certain >99%; extremely likely >95%; very likely >90%; likely >66%; more likely than not > 50%; about as likely as not 33% to 66%; unlikely <33%; very unlikely <10%; extremely unlikely <5%; exceptionally unlikely <1%.