In simple terms, the four storylines combine two sets of divergent tendencies: one set varying between strong economic values and strong environmental values, the other set between increasing globalization and increasing regionalization . The storylines are summarized as follows (Nakicenovic et al., 2000):

“‚⠠ A1 storyline and scenario family: a future world of very rapid economic growth, global population that peaks in mid-century and declines thereafter, and rapid introduction of new and more efficient technologies.
“‚⠠ A2 storyline and scenario family: a very heterogeneous world with continuously increasing global population and regionally oriented economic growth that is more fragmented and slower than in other storylines.
“‚⠠ B1 storyline and scenario family: a convergent world with the same global population as in the A1 storyline but with rapid changes in economic structures toward a service and information economy, with reductions in material intensity, and the introduction of clean and resource-efficient technologies.
“‚⠠ B2 storyline and scenario family: a world in which the emphasis is on local solutions to economic, social, and environmental sustainability, with continuously increasing population (lower than A2) and intermediate economic development.

Which all sounded pretty reasonable … until I looked at some of the details. The details of the scenarios are available here as an Excel spreadsheet.

First, I looked at total primary energy use. This is the sum of coal, oil, gas, nuclear, biomass, and “other renewables”. I used the four “Message” scenarios as representing the mid-range values. Here are the results:

Now, that all looks fairly reasonable, so I next looked at their population estimates.

These are reasonable as well, with the highest one approximately equal to the UN “high” projection, the middle one equal to the UN “middle” projection, and the lowest ones equal to the midpoint between the UN “medium” and “low” projections. It’s weighted towards the high end, but that’s OK since we are looking for maximum effects.

Then I looked at the energy use per capita. Here things get weird.

Three of the four scenarios project nearly identical increases in per capita energy use, while the per capita energy use in the A1 scenario is off the charts. What’s up with that?

Finally, there has been a lot of talk that the economic assumptions are wonky. To investigate this, I looked at the per capita growth in the four scenarios, and compared it to the economic growth in the US over the last 35 years. This chart shows the percentage growth in the GNP/capita for the four scenarios, as well as the growth that would occur using historical US rates.

To me, their economic assumptions are all way too high. The US economic growth during the last 35 year has been among the world’s strongest. Their scenarios all assume world growth will be either near to, above, or way, way above the recent US growth rate. [Curiously, the average growth rate since 1970 (2.0%/yr) is almost identical to the average US growth rate since 1900 (2.1%/yr), so 2.0% is a reasonable number to use for the US.]

To me, this is ridiculous. Whatever the planet might do over the next century, it beggars belief that as a whole the world GDP growth will match the historical US growth rate, much less be three times as large.

w.

I have to say that I’m rather unimpressed with what I’ve heard in the way of excuses in relation to the growing discrepancy between SRES-type projections and actual measurements of atmospheric CH4 (it came up a couple of weeks ago in a workshop here). IMO this is developing into quite a credibility gap and I hope that there will soon be a better answer than “we don’t know, so we’ll just keep using the old scenarios even though they all already show a substantial overestimate within 5 years of being published”.

After summarising the main conclusions of the unanimous report on “The Economics of Climate Change” by the Committee of which he was a member, Lord Lawson gave some views of his own, including:

(1) “The IPCC’s consistent refusal to entertain any dissent, however well researched, which challenges its assumptions, is profoundly unscientific;”

(2) “Although its now famous ‘hockey stick’ chart of temperatures over the last millennium … is almost certainly a myth, the IPCC refuses to entertain any challenge to it;” and

(3) “The IPCC’s scenarios exercise, which incidentally incorporates a a demonstrably fallacious method of inter-country economic comparisons, manifests a persistent upward bias in the likely amount of carbon dioxide emissions over the next hundred years. For example, a combination of steadily increasing energy efficiency and the growth of the less energy-intensive service economy has led to a steadily declining rate of growth of carbon dioxide emissions over the past 40 years: all the IPCC’s scenarios unaccountably assume an abrupt reversal of this established trend”…

“In conclusion, I believe that the IPCC process is so flawed, and the institution, it has to be said, so closed to reason, that it would be far better to thank it for the work it has done, close it down, and transfer all future international collaboration on the issue of climate change, where the economic dimension is clearly of the first importance, to the established Bretton Woods institutions.

“It is profoundly important that all governments, most importantly their Treasury departments, make their own independent and rigorous economic analysis of the issue. At the time the Lords committee was taking evidence this, for whatever reason, had not happened in the UK. I very much hope that, following our report, it will.

“We appear to have entered a new age of unreason, which threatens to be as economically harmful as it is profoundly disquieting. It must not be allowed to prevail.”

The full text is well worth reading.

I think we are on the same page. The focus at IIASA is on models rather than data, rather like the climatologists and in that case it is unsurprising that it doesn’t occur to the alumni that having national accounts statisticians review things is a good idea.

What we are dealing with is the shortcomings of silos of organizational and disciplinary cultures in dealing with complex and complicated phenomena such as climate change and its social and economic impacts.

As you said, peer review doesn’t help if the reviewers belong to the same milieu/mind-set/culture.

We have to establish new protocols for researchers and reviewers to follow. We probably need a new group of people in the mix too, namely those trained to understand more than one discipline and in the social entrepreneurial skills required to bring people trained in different disciplines to accept, if not fully understand, the need for transdisciplinary auditing.

This is a general problem in technological innovation, by the way. The convergences ocurring among ICT, nanotechnology and biotechnology and the very nature of nanotechnology (in that is by nature interdisciplinary) mean that for efficient and effective exploitation we need people who can translate among disciplines. But the universities are not training such people, only specialists.

I entirely agree with your comment about the need to consider scenarios in which no carbon fuels will be used in the long term future. It is very interesting that in their logistic substitution analysis of primary energies, Marchetti, Nakicenovic and Grubler only consider nuclear after methane and after nuclear some other (undefined) process based on nuclear physics. There is nothing about wind, solar, tidal or biomass, for example.

In the long range plan I helped craft for Greater Vancouver, we did consider such scenarios. When I replicated MNG’s logistic substitution analysis of primary energies with 20 years more data I included non-hydro renewables as the primary energies to follow methane.

The results are highly influenced by what happens to nuclear. For Canada, it turned out that the penetration rate was highly dependent on whether or not nuclear makes a come-back. A nuclear moratorium puts back NHRs considerably (15% in 2040 versus 50%) versus a medium nuclear scenario. On a world scale, renewables chug on to about 20% regardless of the nuclear scenario (high, low, medium) but the methane peak moves around a great deal in time and size. Two explanations suggest themselves: methane-based technologies are highly substitutable for NHRs (which seems plausible re: efficiencies and pollution abatement and support for distributed energy systems); NHRs are simply not far enough their technical and market S-curves to be serious contenders for existing and proven technologies – in the absence of nuclear the energy system gravitates to what works and is economic.

I don’t like that they didn’t include technologies before the prototype stage. If the endpoint is 2100, that would be like leaving out the internal combustion engine in 1860 in an exercise aimed at 1960.

In any case, I don’t believe it is helpful in such long range scenarios to specify particular technologies, exactly because of this problem of being unable to imagine what does not yet exist (but which undoubtedly will). I prefer to use envelope curves of technical performance S-curves and historical analogy. I have an envelope S for machine efficiencies (kindly supplied by MNG) which I can extrapolate. I can create curves for particular machines – known or imaginary – because I can make assumptions about the midpoints and slopes of logistic versions of their Ss based on historical analogy. I am comfortable in doing this because they are historically very stable.

That enables one to create a scenario for energy efficiencies in 2100 and intervening milestones. Then you ask yourself, which kinds of technologies could conceivably achieve those efficiencies. From that you can hypothesize the structures of economies etc. e.g. will they likely be centralized and based on scale economies or decentralized and based on economies of scope.

Mike

First, on the question of whether the IPCC modellers considered if radical new technologies could transform the use and consumption of energy and of carbon based fuels in particular. I think it depends on what one means by “new” and “transformed”.

According to the SRES, in discussing the technological assumptions underlying the MESSAGE emissions scenarios developed at IIASA, “technologies not yet demonstrated to function on a prototype scale were excluded” (Box 4-9, para. 4). It is presumably because of this assumption that the MARKER scenario with the lowest level of cumulative CO2 emissions across the century (the B1 IMAGE scenario) still assumes that almost half of the global energy supply in 2100 will be produced from fossil fuels (SRES, p. 506), and that the scenario with the lowest cumulative emissions across the century of the whole suite of 40 scenarios (the B1T MESSAGE scenarios) still assumes that 30% of the global energy supply in 2100 will come from fossil fuels.

To me, a transformation in the use and consumption of carbon fuels would include the possibility that all energy would be supplied from non-carbon sources by the end of this century. On this reasoning, at least one of the suite of scenarios claiming to cover the whole range of realistic possibilities should therefore have assumed that CO2 emissions from fuel combustion at the end of the century would be nil. I would be interested in your comment on this.

Secondly, on your point that Nakicenovic & Grubler are to be faulted for not having their reports audited a la McIntyre before they release them,
I don’t think that the problem was lack of an audit as such. As I said, the book that Nakicenovic instanced in evidence to the HoL Committee had 115 named expert reviewers, and presumably CUP also had it read by anonymous peer reviewers as well. But David Henderson and I have argued that peer review does not offer security against error when the reviewers all come from the same milieu. This example neatly illustrates the point.

The book that I mentioned appeared in 1998, about half-way through the four-year period during which the SRES was produced. There was a glaring error relating to Indonesia. Surprisingly, none of the 89 expert reviewers of the SRES came from ASIA, while no less than 12 of the 52 members of the SRES writing team came from the Netherlands, and 25 came from EU countries.

At this time the head of the national accounting area of the Netherlands Central Bureau of Statistics, one of the most highly regarded statistical agencies in the world, was Steven Keunig (he’s now moved to be the Head of the Statistics Department of the European Central Bank).

Steven’s doctoral thesis was on the Indonesian economy, and he was subsequently the main author of a UN study in the application of a system of national accounts in a developing country, taking Indonesia as an example.

I’ve no idea whether Steven was asked to review the IIASA/WEC book. He would certainly have set IIASA right on Djakarta’s output as a % of Indonesia, and on many other statistical failings as well – but so could many other national accounting statisticians at the CBS or at Eurostat.

They just didn’t recognise the need for professional statistical input and, so far as I can see, IIASA and the IPCC are still of the same mind. They use technical statistical concepts but fail to see the need to find out what they mean. So while I applaud IIASA’s interdisciplinarity as far as it goes, it doesn’t extend to economic statisticians.

More generally, I stress that I am not criticising the IIASA approach in principle. The point is rather that a wider range of inputs was necessary to do what they & the IPCC were trying to do in the scenarios (including from economic historians, historically minded economists, national accounts statisticians and index number theorists). In my opinion, the problem is still not recognised.

RE:62

I am not trying to carry a flag for messrs Nakicenovic and Grubler. I was just trying to throw some light on the question asked in the quotation, whether the IPCC was likely to have considered if radical new technologies could transform the use and consumption of energy and of carbon based fuels in particular.

From what I know of their work, I think the answer is certainly “yes”. Whether they made errors in their analysis is another question which I am not qualified to answer since I have never read the IPCC report in question.

The thing about IIASA in my opinion (I have been there twice and talked with Nakicenovic among others) is that with its multi-disciplinary systems approach, it is not surprising that the kinds of details you cite slide between the cracks. They are to be faulted, I suppose, for not having their reports audited a la McIntyre ( ) before they release them. Given the risks of error inherent in their approach, they really ought to have done.

On the other hand, they have turned out some brilliant stuff as a result of their approach, for example Kindler’s work on pollution plumes, and I certainly put the work on invention, innovation and energy substitution which Marchetti and Nakicenovic did in that category. Marchetti was a nuclear engineer, by the way, who worked at CERN. It is often the case that breakthroughs in a science or a technology are achieved by outsiders with a fresh perspective. Think of DNA – there was only one biologist in the team, the others were two chemists and a physicist. Together they revolutionized biology and created an entirely new discipline (microbiology). Bessemer, who revolutionized the steel industry, was in paints and glass. There are many, many examples of this.

Inevitably, in the process, there can be errors and misfortunes, but the end result is often very beneficial.

I certainly support your view of the Haefele study, which has come in for a great deal of criticism over the years.

Anyway, this thread and our discussion has persuaded me that I really ought to go and read the report in question, as my knowledge of the kinds of analysis Nakicenovic and Grubler use could probably provide some useful insights.

Mike

P.s. for a company: you earn what you earn. If you liquidate the firm and count the money, it’s the currency rate that matters, not the EU-beaurocrat-beloved PPP metric.