Category Archive

Well, not so  much a hiccup, actually, more a small heart attack.

Happened a week last Saturday Night (probably the fourth of a short series),

Operation on Thursday put in two stents.

Now home and recuperating, but obviously, not overly active, for a while.

Honest, it had nothing to do with the paper…

This will probably give me a bit of time to trawl around the blogosphere and irritate a few folks.

Apologies to all those who were expecting to hear from me. Now you know why.

Some interesting may conceivably follow in the days to come.

It’s not even as if I’m actually really that old, you know….

First and above all, thank you to the several people who have commented, both here and elsewhere, on the poll of scientists’ opinions which we conducted and which has now been put up on Roger Pielke Sr.’s weblog.

Thank you to our fellow climate bloggers, who have been supportive and engaged themselves, for their comments and feedback.

Thank you to the people who have sent emails, and those who have given permission for extracts to be used on the website.

Now, to some points which arise from all the comment and discussion, to some clarifications and questions.

Does the opinion poll, as we conducted it, say, or hint at, anything important?

Does it matter what (climate) scientists think about the IPCC WG1?

Does the reaction to the paper in itself raise important matters?

To the validity/value/significance (hello to Steve Bloom) of the poll itself:

As I have explained elsewhere, in the absence of a known community, a properly conducted sample poll is not generally an option. Where there is an identifiable specialism, however, it is generally considered acceptable to sample a subset of the community, so long as it can be seen to be in some way representative of the larger (undefined) community.

I believe that, in the methodology adopted, and in particular, in the efforts made to eliminate sample errors in advance by triple-checking the suitability of the people sent the questionnaire, we successfully met the criteria for an acceptable subset of the community of scientists engaged in disciplines closely related to climate or climate science.

I further believe that, in sending questions to people in more than fifty countries, and in selecting second and third authors/presenters as well as first authors/presenters, we have met an acceptable standard of inclusiveness across the range of age, nationality and discipline, whilst retaining that original criterion.

Where our poll fails to meet the rigorous standards of statistical significance (about which we are open, not as a ‘get-out-jail’ card, but as recognition of the limitations of our work), in other words, the number of respondents and the risk of self-selection bias, are matters which were beyond our capacity to control. We could have chosen to limit our sample, or select a more specific subsample, but the same problems, of identifying the relationship between the subset of respondents and the larger community, would still have existed. As with all polls, the number of respondents is  in part defined by the time, resources and finance available to the pollsters. It should be understood that this exercise was conducted with no funding of any kind, in our own time, with only the resources we could obtain via the internet available to us.

In other words, we did the best we could with what we had, and worked hard to get the broadest mix of relevant subjects, in the most open and honest way possible. A lot of comment has focussed on the ’self-selection bias issue’, but on this I will make two comments: first, it has been claimed by one group of people that our poll may well be biased in favour of ’skepticism’, and by the other group of people as being biased in favour of ‘alarmism’. This might suggest to the observant mind that we may actualy have found a decent middle ground. Second, there is as likely to be a bias in favour of ‘the middle response’ as in either extreme. The only way we could ever find out if this preliminary poll was in fact biased is to run a validation test, or a better, larger poll, and compare the results.

I would argue that, the (well-justified) criticisms aside, if you are willing to look at the results as they stand, this work does provide potentially important suggestions/guidance/information. It tells me, anyway, that I will probably struggle to find a genuine ‘denialist’ in the community of people involved in this area. Even a couple of very well-known ’skeptics’ were polled and responded, and they did not opt for out-and-out denial. It suggests that one ‘end’ of the so-called ‘frame of discourse’ on climate science is to all intents and purposes defunct, and can be eliminated from serious discussion on climate change.

In contrast to this, it also does tantalisingly suggest that there really is a reasonably broad range of scientific opinion on the WG1, but that, by and large, the position as represented in the AR4 WG1 paper is the ‘middle ground’, the majority view, the default position. In this sense, if one wished to talk about a ‘consensus’, this suggests that the IPCC represents the ‘consensus position’.

But because the poll also hints at a range of opinion outside the ‘consensus’ view, it also suggests that scientists’ opinions in this respect are important to know about and to understand. I understand the political importance of presenting a clear and strong message about climate change to politicians and the general public, and am an advocate of the same myself, in my own words and deeds. However, that there (probably) exists a range of disagreement about the science as presented in the WG1, which could well be broader than is implied by the summaries and press releases of the official bodies, is not a trivial matter. It may be expedient to sweep such issues under the carpet, but is it honest? Is it right, if one is to be judged as a scientist, by scientific criteria, to exclude data which does not conform to the required results of a test or hypothesis?

What is intriguing to me is what has followed as a consequence of the original poll. One of the most striking things about the comments of scientists and non-scientists alike is that both sets of people are equally prone to prejudice and predispositional attitudes, and both tend to view material as ‘on my side’ or ‘not on my side’, with very little equanimity or balance in evidence. Also intriguing is that our efforts appear to have produced both positive and negative reactions from people of all shades of opinions. To me, this clearly demonstrates that the content of this, or any other piece of writing, is being attributed its meaning almost entirely in the minds of the readers, almost irrespective of its actual content. In other words, what people are getting out of it is what they put into it.

No doubt there will be more to say on the subject, but I would welcome any further comments. As it seems reasonably clear that many people agree that the poll and the paper could have been done better, it would be nice if we could focus instead on the results , rather than the means of getting them. You will have to accept my word that we did our best to honestly gauge the honest feelings of honest scientists. I still think we succeeded, however ‘better’ or ‘differently’ things might have been. So tell me what you think about the results…

Oh, and if I haven’t already made it clear, we really do appreciate your involvement.

Following on from the last post, ‘George’ was asking about mass-production and very small wind turbines. The impression was that he was thinking of extremely small ‘mills’, so for the sake of discussion, we’ll assume that something like the Eclectic Energy Stealthgen, or Marlec’s Rutland 903 is what he had in mind. These are 300 watt, lightweight HAWTs designed to mount on small yachts, lamp posts or road signs; I have seen a few used in this way in Oxfordshire, in conjunction with very small solar PV cells. As small turbines go, they are reasonably efficient for their size, and modestly priced (a few hundred pounds/dollars each). Being made of standard materials and of simple design, they are amenable to mass-production and could, in theory, be mounted in groups of fifty or a hundred in relatively small sites. Would this be a good idea?

To help explain why this would be less efficient (in both materials and productivity) than larger systems, a few very important basics of wind power need to be covered. I’ll skip some of the detail, but the principles are well-understood and already factored in to many manufacturing decisions.

The two most critical factors in the amount of power which can be generated from any wind turbine are the strength of the available wind (the wind energy potential) and the amount of wind ‘going through’ a turbine’s blades (the swept area). Other important factors include the ‘quality’ of the wind resource (energy-reducing elements such as shear and turbulence) and the siting of the turbine relative to surface conditions (surface roughness).

The greatest amount of wind energy potential anywhere is relative to height above ground level; the higher you go, the more energy is available. This is able to be calculated using the wind power law or the wind log law. Even a difference of a few inches can increase or decrease the average amount of wind received at the turbine head. And it is the average, or mean wind, which matters here; both in terms of directional stability and long-term unit productivity. This is why large wind turbines want to be sited on tall masts.

The ‘down-side’ of this factor is that effective (by which I mean cost-effective) installations are likely to be, by definition, visible in the landscape. Without going into the arguments here, I’d suggest that almost all of the objections (in the UK at least) to wind installations derive from people believing they will be visually intrusive or ‘ugly’. My simple response is that in many cases a single small or medium-sized turbine has considerably less visual impact than a radio mast or electricity pylon, and that, assuming that the aim of objectors is to preserve the countryside they cherish, the long-term view must be that, without renewable energy, the countryside is likely to be transformed in ways which are more permanent, more damaging, and more ‘ugly’ than almost any alternative.

The relation between swept area and power output is in a squared proportion. A turbine which sweeps 10% more area than an alternative will give perhaps 40% more power (I can’t be bothered to do the sums today) for the same wind energy available. This explains why the manufacturers of large systems, such as the ones used on wind farms, are focussing their production on ever-larger, ever more powerful turbines. In fact, most of the companies which once produced ‘mid-sized’ systems no longer make them at all. This is a matter which I’ll return to later, in discussing ‘affordable’ local solutions.

This does not mean that there is no place for small wind systems; on the contrary, ’small’ wind could (according to recent estimates) account for a sizeable percentage of the entire UK’s ‘domestic’ energy use. It also does not mean that only large systems are economically viable. This is because, whilst wind farms needs to justify their costs by providing a return on investment and productivity at rates of 2-4 pence per kWh, small systems only need to work out as competitive in relation to end-user energy charges (tariffs), in order to be worthwhile. Having just seen a 13% rise in electricity charges yesterday, anyone who has energy generating capacity to replace that provided on the grid is making a net gain, since energy prices are rising faster than background inflation.

As things stand, with the technology currently available, (and depending on individuals’ current best available tariff), if a small turbine can produce 700-1100 kWh per £100 spent ($200), then it is probably going to both pay for itself and provide a long-term net return on the cost. If domestic users are willing to accept a small penalty in terms of cost in return for making a contribution towards reducing emissions, then the productivity can be even lower. Given the likelihood of ongoing long-term energy price inflation, a canny reader might realise that, so long as the additional cost is less than the sum of the inflation over the turbine’s lifetime, there is a reasonable chance that no cost will be incurred at all.

Rather than a field filled with extremely small turbines, then, I’d suggest that a chain of slightly larger ones (5-25 kW), is a more practical and more economic idea. In the next post or two, I’ll continue with more reasons why it works out this way.

In the meantime, if you have been thinking about putting a wind turbine up but aren’t really sure whether it is for you, or if you have a company which is suffering because of the high cost of energy, be warned that the Old man is now working for an engineering company in the UK which installs these things; get in touch, and I’ll try to help give you some answers (no charge, since it’s you…).