When I worked as part of a team made up of nationals of several different European countries, we’d be fond of swapping phrases from different languages (all translated into English). Most would make Hank Paulson blush, and this is a family blog. But one I liked was the equivalent of the English phrase “to make a mountain out of a molehill”. In Holland (or was it Greece?), you’d say instead “to make an elephant out of a mouse”. So, of course, we combined the two and made elephants out of molehills and mountains out of mice. My most notable contribution was the phrase “pissing in the wind“.

What’s bugging me is the question of the potential for generating energy from wind-power. In what’s fast becoming the Bible for such matters, Sustainable Energy Without the Hot Air (SEWTHA), David MacKay asserts that you can only practically generate around 2W of wind power per m2 on or around the UK.

David therefore concludes (page 216) that the UK could feasibly build 35GW of onshore capacity and 29GW of offshore, total capacity 64GW, producing on average 4.2kWh/day/person and 3.5kWh/d/p, 7.7kWh/d/p in total. (Other energy plans for the UK including more or less wind energy are discussed elsewhere in SEWTHA).

Sorting out the units

One man’s sensible units are another man’s bizarre eccentricity. I want to convert David’s units for comparison with other, even more eccentric, sources. Personally I’d like to divide by 24 to get rid of both the hours and the day – David’s wind totals 7.7kWh/day per person, that is 7700/24W per person – call it 300W. Now we’ve got to something I can relate to! And I don’t know, but 300W seems not a lot more than the lights and the TV to me! Maybe we’re going to discover the wind won’t save us…

Anyway, figures are often given in TWh/year for the UK. Strange but true.

I assume MacKay bases his estimates on 60m people. So 7.7kWh/d/p is 7.7*60m*365kWh/yr for the UK or 7.7*60*365GWh/yr = ~170TWh/yr.

How much wind do we need for 1 million jobs?

David MacKay is now an energy advisor to the UK Government, so his view counts. But I keep reading higher figures for the potential for the UK to generate wind energy than 170TWh/yr.

For example, on Saturday I picked up a booklet One million climate jobs NOW! which notes on p45:

“In 2008 the total UK supply of electricity was 401TWh. 7TWh of that came from wind. In 2008 the UK had 3.4GW of installed wind power. So approximately 2TWh of electricity were produced that year for each [G]W of installed capacity. [So far so OK: cf David's 170/64 or a bit over 2.5TWh/yr/GW installed capacity]. 150GW of installed capacity should produce 300TWh, three quarters of current electricity production.”

Obviously, if there is not enough wind for 150GW of capacity and/or for 300TWh/yr, the whole 1 million jobs plan starts to unravel.

Sorting out the units again

One man’s sensible units are another man’s bizarre eccentricity… What does “150GW capacity” mean? Let’s work instead in terms of average output, because we’re going to be considering average wind-speeds (really we should be considering average power in the wind, which is different, but, hey, the modern Principia will have to wait!). Let’s go back to the energy needed of 300TWh/yr. What average power output do we need to achieve this?

What a pretty pass we’ve come to when we’re calculating in Watt-hours per year!! We want Watt-years per year, in other words, simple Watts!! There are roughly 24*365 = 8760 hours in a year, so 300TWh/yr = 300,000/8760GWyears/year = 35GW, rounded up a tad.

To create 1 million jobs we need to build enough wind-turbines to give an average power output of 35GW.

Is there enough wind?

Now we can finally start to make comparisons. How much wind is really out there? And how much of that do we need?

What’s been bothering me for some time now is that MacKay bases his figures (all derived from the 2W/m2 power density) on wind-turbines having to be spaced in a grid 5 times their diameter (5d) apart, as described in his Technical Chapter B, p.265.

This argument seems to apply to current technology only, but is also somewhat counter-intuitive as you would have thought you could simply put taller wind-turbines in between the ones you’ve already got and they wouldn’t interfere. If you only used 2 heights you’d double up to 4W/m2 and we could create our 1 million jobs, moreorless.

In fact, the idea that you can only extract the same amount of energy per unit land area whatever the diameter of the wind turbines is somewhat paradoxical. Surely 1cm turbines spaced 5cm apart is not going to be as good a solution as 100m turbines spaced 500m apart! All very odd: MacKay’s Paradox, perhaps!

Furthermore, it would seem the proximity of other wind turbines is only a problem downwind. Perpendicular to the direction of the wind it might even be better for the turbines to be next to each other as, like New York skyscrapers, the resistance of one would force air towards its neighbour. In many locations useful wind will normally come from one direction (the west near the UK). If only the downwind turbines have to be 5d apart, then you should be able to generate 5 times as much energy, 10W/m2. Now we’re talking!

But I don’t want to stop here. With different designs, e.g. turbines at different heights or funnelling air towards turbines, you might be able to do even better than that. In principle you should be able to capture a proportion of all the energy in the wind up to whatever height you could engineer. How much energy is this?

Problem

MacKay (Chapter B, p.263 ff) only considers the kinetic energy of the wind passing through a single turbine.

But we know that the wind turbines interfere with each other, otherwise we could put them right next to each other and there’d be no 5d rule of thumb. What I’d like to answer are questions such as:
- what proportion of the energy in the air does a large field of wind-turbines extract?
- can we do better than extract 2W/m2 with better technology?
- are we likely to hit any limits, i.e. can we extend a field of wind-turbines indefinitely without weakening the wind?

Obviously this is just a blog (but, hey, what might it lead to?), not a scientific treatise on the subject. Nevertheless, we can take a stab at answering these questions.

Thought experiment

Let’s work out the kinetic energy of the entire mass of air up to the top of the atmosphere passing between two imaginary poles a metre apart across the 6m/s wind direction. A quick calculation shows that this column of air – 15psi (sorry, pounds – 2.2/kg – per square inch – ~2.5cm2 – you can do the calculation yourself – OK, the conversion is 15psi = ~15/2.2*40*40kg/m2) in old units – weighs ~10000kg. Wow!

If the wind speed all the way to the top of the atmosphere is an even 6m/s (a conservative assumption as it moves faster higher up, we’ll try to come back to this), then the kinetic energy of the air passing between the poles every second is, by the formula 1/2mv2, with 6m of air passing every second, 1/2*6m*10000kg*(6m/s)^2 = ~1 million Joules, that is, (1 Joule per second =1 Watt) we have 1MW of power every metre across that there gentle breeze. Wow, again!!

This is rather different to the figure of 140W/m2 (note the different units) David MacKay calculates because he only considers the energy in a cross-section of the air, the 1.3kg/m3 that actually passes through a 1 m2 cross-section of wind-turbine. The wind goes up a long way and (by these back of an envelope calculations) only 140/1 million = 0.00014 or ~1/7000th of it passes through a 1 m2 cross-section near the ground! (The calculation by mass of air considered, i.e. 1.3/10000, gives roughly the same answer).

But the wind comes from somewhere. If you had many rows of wind turbines, part of the energy will be extracted by each row. The wind for the later rows will have to come from somewhere or we’d be becalmed. The answer is it comes from the other 9998.7kg of air above the wind turbines!

This rather explains MacKay’s Paradox, since we have to suppose air can only fill the lee (downwind) side of the wind turbine from above or below or even from the sides (so perhaps we can’t put our turbines right next to each other after all) at a limited rate (mostly from above). When a wind turbine creates a partial vacuum, the engineers’ rule of thumb used by MacKay is that a “hole” 1m in diameter is filled in 5m, 100m in 500m and so on.

OK, not all the air will necessarily be moving in the same direction (otherwise the weather system we know & love wouldn’t operate as observed), but if even half the mass (remember the air is less dense the higher you go) is, we have 5000kg of air and 500kW/m2 to play with.

Even if we can only extract 1% of this energy, that works out at 5kW/m2.

We can’t keep extracting 1% of the energy, though, from row after row of wind turbines, so maybe we should consider the air-mass to be a wall of wind, from which we could extract, say, 10% of the energy in total, that is, 50kW per metre length of the wall. This is equivalent to funnelling all the air through 100% efficient wind-turbines, that is, extracting all the energy in the wind, up to a height of 50,000/140 = ~350m (the 140W/m2 is David MacKay’s power per unit area of wind-turbine at a wind speed of 6m/s).

Or, perhaps more practically, we could extract around 1/3 of the energy (MacKay suggests 50%, but I’m going to be a bit less optimistic) in the air up to 1000m, one kilometre. (Note that this doesn’t allow for air density decreasing with height, but then again I’m not yet making any allowance for the fact that the wind-speed increases with height).

To obtain the 35GW average power output we need for our 1 million jobs would therefore need a wall of such wind-turbines 35GW/50kW = 700,000m or 700km long. Ouch!

Or perhaps, since we’re talking about the UK, we could have a 1400km wall of wind turbines 500m high, which sounds a bit more practical.

Implications

My 1400km wall of wind-turbines 500m high is very roughly equivalent to (say) a field of large wind-turbines (100m+ diameter) 1400km, that is, 14,000 wind-turbines long (i.e. around the whole length of the UK), right next to each other, but only 5 wind-turbines, that is, with 5d spacing, 2 km across.

The “wall of wind” is therefore equivalent to ~14,000*5 = ~70,000 wind-turbines in total, implying an average output of of 35GW/70,000 or 0.5MW at a wind-speed of 6m/s. Wind turbines are normally quoted in capacity. The 35GW average output was based on a capacity of 150GW and empirical rather than theoretical figures relating average output to capacity. Anyway, my calculations suggest the wind-turbines each have a capacity of 150GW/70,000 = ~2MW, which is a little bit low for such large devices, but in the right ballpark. In particular, I’ve estimated cautiously for the efficiency of the turbines and have made no allowance for a higher wind speed at a higher altitude.

This higher wind-speed is absolutely crucial, because what I hope I’ve demonstrated is that a field of wind-turbines actually extracts energy from higher up in the atmosphere. A field deep enough would actually slow the entire air flow. What happens is that the first row of wind-turbines slows the air, creating a partial vacuum downwind. This is filled mostly from above, slowing the air higher up.

Consider the graphs of wind-speed against height and power density of wind against height David gives here. They’re astonishing. The wind power at a 10m height is around 100W/m2 for a 6m/s wind at that level, but at 100m where the air flows faster it’s nearly 250W/m2 and at 200m where it flows faster still we’ve got over 300W/m2 to play with!

What’s actually happening, of course, is that all the other things on the ground – water, trees and so on – are already capturing the energy in the lowest part of the atmosphere, which fills from above.

Or, to look at it another way, the wind is created by a high pressure mass of air essentially collapsing into a low pressure area, which literally fills, as the weather-men say.

Bearing all this in mind, it seems to me that we’re pissing in the wind in the first place building wind turbines near ground level. We should start 100m or 200m or even 300m up.

Conclusion

There is (significantly) more than 500kW/m or 500MW/km of kinetic energy in a flow of air – 100s of kms across – moving towards the British Isles at an average speed of 6m/s, creating what we call a (west) wind. If we could extract all this energy we’d “only” need a 70km wall of wind turbines for an average output of 35GW.

The limit of 2W/m2 only applies to the technology we are using just now to extract energy from the wind. At this stage in the development of the industry, there are plenty of sites and it’s the technology that’s expensive. This will change over time, and there will be an incentive to design machines to extract more of the energy from the wind, particularly higher in the atmosphere.

It may be possible to extract significantly more than 2W/m2 by building turbines closer together across the wind direction and (as, to be fair, David MacKay points out), much taller.

However, maybe we have to bear in mind that we might not be able to build row after row of giant wind-turbines indefinitely. From a British Isles (UK and Republic of Ireland) point of view this might not be too much of a problem, since we are on the western seaboard of Europe. But eventually if we build turbines along the west coast, perhaps along the spine of the country and in the North Sea, we could just conceivably start to affect the very wind itself – the Danes and Germans might not be so pleased!

To determine whether this hypothesis is true, we have to look at other aspects of the energy in the wind. The kinetic energy arises from the potential energy of different pressures of different air-masses. And we need to look at how that potential energy itself is generated.

In other words: how renewable is the wind?

Another time, maybe.

I began reading “Carbonomics” by Steven Stoft late yesterday. I’m only just starting Chapter 3 (of 31) but I can already reach a conclusion.

My very first impression was that “Carbonomics” brings some logical thinking to the debate. I see no reason to change my view: there is no doubt a lot of good material in the book.

But within minutes I could see that Stoft’s overall prescription, sadly, is in dreamland.

I’m posting my initial thoughts immediately whilst I am still in a state of shock.

The history of thought is littered with discarded, but complex and sophisticated, bodies of knowledge, from scientific theories – the Ptolemaic universe perhaps, to political programmes – communism, for example; indeed more than bodies of knowledge, entire institutions, even civilisations, all built on foundations that later proved to be constructed of no more than intellectual straw.

Some of the foundations of “Carbonomics” consist of no more than straw.

I am indeed stunned. I started reading and first came across some encouraging comments in the Preface (a chapter which should never be skipped). The author notes the inefficiency of current policies to improve energy security and global warming and promises to “fix energy policy”. He will be guided by the story of physics, and produce Mr Tompkins in Wonderland for economics. “The hardest part of learning new ideas is giving up misconceptions”, he writes.

I must admit that by this point I was already starting to feel a little uneasy. I don’t, for example, believe that “physicists have a tradition of explaining advanced ideas to the public just because they find the concepts fascinating.” No, they do it to try to prove how clever they are (except for a small number who simply have Asperger’s syndrome). And, given that their belief system doesn’t hang together (relativity and quantum physics are as yet unreconciled) they hope that the more positive feedback – or pats on the back – they can extract from their audience, the truer what they have told them will become. Stoft notes that Einstein “found the uncertainty of quantum mechanics… so disconcerting that he never accepted it”. Quite right. Einstein was a holistic thinker. That was his genius. All the facts had to be taken into account, however alien a theory eventually resulted. He understood that all may not be as it seems, but he could not accept contradictions into his world view, even if others could live with them. So in asserting that “God does not play dice”, Einstein was not being a stick in the mud, but demonstrating he was on the side of the good guys. Even if he didn’t have the whole answer, at least he knew there was a question.

I labour the point because it soon became apparent that Stoft’s thinking is not sufficiently rigorous. He is not prepared to accept inconvenient truths.

It’s a shame, because Stoft starts so well with an excellent account of the effects of the 1970s oil price spike. When the Great Depression is so often mentioned as the worst of economic times, I often feel that the discourse is US-centric – cultural domination perhaps. For the 1970s was as decisive for modern Britain as the 1930s was across the Pond. Inflation and unemployment, a pervasive sense of decline tinged with incipient anarchy. The Punk Era, swept away by the Thatcher Revolution.

Never mind, my point is that Stoft’s prescription will fail. Reading his first chapter I assumed Stoft would urge measures to keep the oil price high. But it suddenly dawned on me that his prescription is the precise opposite!

There’s a why Stoft is wrong, which owes something, I feel, to a US-centric world view.

And then there’s the how Stoft is wrong. I’m afraid to say he has not followed his own prescription in the last line of his Preface, to “pay close attention to the way governments and markets really work”.

Stoft, it seems, still bears grudges against OPEC. On page 4 he explains how he wants to avoid “paying OPEC another trillion dollars in tribute”. He writes of how, by 1986 “OPEC had been crippled”. On p.5 he notes how he will explain “how to crush OPEC again”. On page 6 he reminds us that “conservation… crushed OPEC in the early 1980s”. There’s a bit of a lull while he advocates a “consumers’ cartel” to counter OPEC and worries about how to deal with “free rides”…

Powerful stuff. Where have I heard this sort of thing before? Oh, yes, I remember now – it’s eerily reminiscent of Russia railing against NATO. Yes, that’s right, Russia’s demon is a mutual-defence pact. To many in Russia (unfortunately many of those in positions of power), the idea of Ukraine or Georgia joining NATO – to ensure, as sovereign nations, their own defence – is little short of an invasion of the Motherland itself. I wonder, I just wonder, if OPEC members feel the same way. Let’s just step into Wonderland for a moment. Maybe they feel they have a right to the riches under the desert (or wherever). I know, I know, I’m of the view that oil wealth is a fortunate (or often not so fortunate) windfall. But the actual state of affairs is what we have to deal with – and de facto those countries endowed with generous fossil-fuel reserves are determined to maximise the value of those reserves.

In solving the problem of global warming (and energy security) we have to deal with the world as it is, not how we would like it to be.

Maybe I can lay down something of a more specific principle here. Short of war, there will only be progress in international negotiations if win-win situations are created. Sorry about the cliche. Maybe I can get rid of it. Because, actually, we’re in a multilateral situation and we need win-win-win… in fact a win superscript n, win raised to the power of the number of interest groups.

Stoft is writing from the US. Let’s put to one side that he hasn’t even convinced his own country’s body politic to take the problem seriously yet, let alone of his particular approach. Let’s pretend he manages to do that. Even if that were to happen, I’ve got news for him. The world out there is not full of buddies who will be happy to participate in a “consumers’ cartel”. In fact, it may be unfair only to Canada & Australia to say that the US has only one reliable sidekick with any clout at all on the world stage. Yeap. Be nice to the UK. OK, I’m being facetious – there is some alignment of national interests, at least with the EU and Japan. But the problem is that several populous developing countries show no clear sign of wanting to play ball.

I feel I’ve written moreorless enough for a first reaction, so it’s fortunate that how Stoft is wrong has already been touched on in previous episodes of Uncharted Territory.

The general problem is the Displacement Fallacy, though I appreciate that Stoft intends to avoid this through international agreements, starting with China. Good luck, mate, but I don’t think you’ll manage it.

Reflections on Oil supplemented by Reflections on Reflections on Oil considers how the oil market will react to attempts to choke off demand. The important point is that the oil producers themselves will act as buyers of last resort.

Before I sign off I should mention that Stoft’s discussion of a tax on fossil-fuel and an “untax” (general distribution of the tax revenues) will not work as he seems to expect for imported products. Stoft is clearly unaware of the Man in the Wardrobe fallacy. Oil at $80 + $20 tax (Stoft’s example in ch.2, on p.21) will not have the same outcome as oil at $100. In the first case, the importing country still has $20 to spend, perhaps on more oil imports or perhaps on other goods, the sellers of which can themselves then afford to import more oil.

I haven’t read enough yet to determine whether Stoft is aware of the rebound effect or Jevons’ Paradox, whereby using a resource more efficiently can actually increase consumption in the long term. The signs aren’t good, though.

Although I’m disappointed with Stoft’s overall vision, I will read on, because large parts of Stoft’s analysis are sound. The first part of chapter 2 shows, for example, how cheap it would be to move away from reliance on fossil fuels.

Watch this space.

—–
As an unreferenced endnote, I admit hypersensitivity to inaccuracies or ambiguities and two have been particularly irritating:
- in Ch.2, footnote 1, p.19 Stoft writes of a policy “that would ‘cap the long-term concentration of greenhouse gases [GHGs]… at 450 [ppm]‘. We are now just over 380 ppm.” CO2 alone is at “just over 380 ppm”. I can only guess whether the policy proposal referred to is to keep all GHGs at a CO2 equivalent level of 450ppm or to keep CO2 below 450ppm – which, it’s now becoming clear, would be too high.
- at the start of Ch.3, on p.21 Stoft remarks that: “Back in the 1800s… Jevons predicted peak coal in England”. Maybe it’s a cultural thing, but to me “the 1800s” refers to the decade 1800-9, inclusive. Stoft means “the 19th century”, here. Jevons in fact wrote “The Coal Question” in 1865 (Wikipedia). And, btw, he was probably talking about Britain, not “England” (Wikipedia thinks so). No offence taken.

Scientific American’s customer management is appalling. When I first subscribed to the print edition, the magazine’s online presence was trumpeted as one of the benefits. I therefore understood I would also obtain access to the Scientific American Digital (how quaint!). Nope. I got no more online access than I had previously and ended up paying a Scientific American Digital subscription on top of the print subscription. Someone should call the Advertising Standards Authority! (Annoyingly my online subscription has now expired, and, I see from the correspondence page – which publishes letters on topics in the edition, I kid you not, 4 months earlier, like we’re still in the 1950s – that I appear not to have received the July issue at all).

Just lately – in the midst of a UK postal strike – I can find no way to notify my address change or even log on at www.scientificamerican.com. The site recognises none of the several numbers on the address labels of the magazines I’m sent. The contact email address intl@scientificamerican.com simply doesn’t work. Mind-blowing. Scientists, eh? Hardly surprising there were dodgy solder-joints at the LHC, was it?

Nevertheless, I persist with Scientific American. It’s worth it for the quality of the articles. And, I have to say, its old-fashioned feel.

The lead article in the November issue is titled: “A Plan for a Sustainable Future”, by Mark Z Jacobson and Mark A Delucchi . It discusses how the entire world could be powered by wind, water and solar power by 2030. And it’s well worth a read.

The authors note that building “millions of wind turbines, water machines and solar installations” is not without precedent. For example, “during WWII the US retooled automobile factories to produce 300,000 aircraft”. For clean energy the numbers are feasible: the list includes 490,000 tidal turbines, 3,800,000 5MW wind turbines, 49,000 concentrated solar power (CSP) plants and 40,000 solar PV plants.

I’m afraid I have some quibbles:

• The authors quote a US Energy Information Administration projection of 16.9TW of global energy demand in 2030, compared to 12.5TW now.  I suspect 16.9TW will prove to be a massive underestimate.  As well as a greater population and higher living standards, there’ll be new sources of demand in 20 years, for example, for large numbers of desalination plants to produce fresh water.  I’d be amazed if we aren’t using twice as much energy by 2030 as we are now.

• On the other hand, ruling out wind and solar power production “in the open seas” is suspect: I would have thought there was a lot of scope to generate power there, e.g. on floating islands, which I’ve seen proposed, probably in Scientific American itself.

• Nuclear power is dismissed because of the “carbon emissions” caused by “reactor construction and uranium mining and transport”, but no explanation is given as to why these activities couldn’t be powered by clean energy.

• Interestingly, the authors are concerned about all forms of pollution, so rule out carbon capture and sequestration (CCS) and biofuels on the grounds of air pollution other than CO2. I’d have liked to see at least a nod to the other problems with these primitive technologies: principally the difficulty of capturing all the CO2 in a coal-fired plant, the cost of burying the carbon and the risks; and, for biofuels, the land use problems – not just food vs fuel, but that the land would store carbon quicker if left alone!

• I doubt that geothermal energy is “renewable”.  There may be a lot of it, but the rocks will reheat only very slowly.

• The authors suggest that we deploy 1,700,000,000 – yeap, 1.7 billion – “rooftop photovoltaic systems”.  I think this is nuts.  First off, I’m really struggling with the numbers – the 0.003MW – or 3kW – size of each system must refer to average (mean) output to be consistent with the rest of the article.  But, according to my mate David MacKay (print edition, p.40), 20W/m2 is going some for solar PV in the sort of countries where there are a lot of roofs. So these systems would have to be 150m2 each. They have big roofs in America, I guess. But my more fundamental objection is that the output of 100,000 of these babies only adds up to 1, yes one, of the 40,000 PV power plants. What’s easier, do you think, fit solar panels on every roof in a medium-sized town, such as Southampton where I come from, or stick them all in a big field outside of town (perhaps a long way outside, like in North Africa, where funnily enough you need far fewer panels)? I’ll give you a clue: let’s be pessimistic and say it takes 1/2 hour to put a panel in a standardised array in a field and optimistically 2 days to put the scaffolding up so you can get on the roof without a health and safety violation – before you start the pretty much bespoke installation process. Barmy idea, isn’t it? I worry that the inclusion of the rooftop PVs owes more to some kind of philosophical belief in the virtues of localism than to sound scientific (or economic) reasoning. And of course the article concludes by advocating the dreaded feed-in tariffs. What better way of transferring money to those with big roofs from those, um, without big roofs?

Nevertheless, notwithstanding a few hints that it may be informed by countercultural ideology, I recommend taking a look at “A Path to Sustainability by 2030″.

But the November 2009 Scientific American is worth buying for another article alone. No, not more minute analysis of the “Hobbits of Indonesia” (not read that one yet, but – to go all Iain M Banks for a moment – does the obsessive human interest in the details of our family tree perhaps represent some kind of species-level insecurity?), but “The Rise of Vertical Farms” by Dickson Despommier. The author should perhaps have credited “The World Without Us“, but he makes the point that we should farm indoors and leave nature to absorb the excess carbon we’ve been stuffing into the atmosphere.

The key argument is that you can grow so much – so much less riskily too – in controlled climate conditions indoors: “4 growing seasons, double the plant density, and 2 [or more, surely, of many crops - judging by a photo I once saw in the Guardian of a hydroponic indoor vegetable farm in Tokyo] per floor”, so that, excusing the quaint American units, a “30-story building covering one city block [5 of these 'acre' things] could … produce 2,400 acres of food”!

Despommier worries about how his vision can be made to happen, but in fact it’s simple. As soon as a realistic price is put on ecosystem services, there’ll be a huge economic incentive to invest in “vertical farms”.

Oh dear, oh dear, oh dear! Hubris meets rationality…

I very much enjoyed Freakonomics. I see from the position of the bookmark in the copy on my shelf that I’ve read past halfway, so it must have been good. I recollect that I was particularly impressed by the discussion of the absence of ill-effects of a policy of random selection of pupils by over-subscribed schools in Chicago, clearly the fairest solution. In fact, I remembered the discussion of random selection in Freakonomics just last week when I read of a rant by a Mike Best, Headteacher, Beaminster school, Dorset:

“It was George III who said that the pathway to hell was paved with good intentions, and so it is with Labour initiatives. They have ranged from the mad (random allocation of school places)…”

Sir, George III was famously mad, and, if I recollect any history at all, died before the Labour party was even formed…

Unlike George III, the Freakonomics authors, Levitt and Dubner, urge policy to be made on the basis of dispassionate analysis of data. And not, perhaps, on the say so of so-called experts with a vested interest.

Considering myself an arch-rationalist, I eagerly read an article by Oliver Burkeman in today’s Guardian discussing the sequel to Freakonomics, Superfreakonomics. I didn’t know whether to laugh or cry.

The reviewer’s comments make interesting reading too. Burkeman writes, for example, that:

“Those arrested on charges of terrorism, [the authors] explain, are disproportionately likely to rent their home, have no savings account or life insurance, be a student, and have both Muslim first and last names. Superfreakonomics makes no mention of the possibility that the police might simply be targeting Muslims disproportionately, and Levitt seems genuinely baffled that anyone might object, on civil-liberties grounds, to targeting all those who fulfilled the relevant criteria.”

Burkeman seems to be implying that he believes behaviour likely to lead to arrest on charges of terrorism is evenly distributed throughout the population, and that Muslims are therefore being targeted unfairly. Maybe I’m missing something here, and I don’t want to offend anyone, but isn’t the main terrorist threat at present from Muslim extremists? Just as a while back the main threat in the UK was from Irish nationalists? Or are these social phenomena just a figment of my imagination? Maybe in WWII British soldiers took more Germans than Americans prisoner just because they were targeting them disproportionately.

But this is nothing compared to Burkeman’s discussion of Superfreakonomics’ espousal of the geo-engineering plan to block out sunlight by “pumping large quantities of sulphur dioxide into the Earth’s stratosphere through an 18-mile-long hose, held up by helium balloons…”. Apparently, Nathan Myhrvold is promoting the idea. He should know better as well.

Anthropogenic stratospheric SO2 injection is a complete and utter non-starter, for the simple fact that warming isn’t the only problem caused by CO2 emissions. This has been very well known for some time. Conferences have been held to discuss the problem. I’d have expected Burkeman to know this.

5 minutes thought might cause one to wonder as to the biological effects (the impact on ecosystems, crop yields…) of decreasing light reaching the Earth’s surface – at the same time as CO2 levels are increasing. And you’d still have time to realise that we’d have to keep squirting SO2 into the stratosphere indefinitely, because it only stays up there for a short while, whereas the warming CO2 will remain in the atmosphere until we stop emitting it and/or do something to get the level in the atmosphere back to pre-industrial levels. Any disruption of the SO2 hosing process for any reason (war, terrorism, economic dislocation, court injunctions…) would lead to rapid temperature increases, because the CO2 would no longer be masked. And before the egg-timer rang you’d realise that any hint of adverse side-effects would make the plan entirely impractical on political grounds.

Myhrvold and the Freakos (sounds like a 60s rock band, don’t it?) have, it seems, walked into the hubristic trap of believing they understand the whole problem. Messing with the biosphere and the climate system requires other forms of analysis than the correlation of data-sets and a good understanding of the importance of the role of incentives in explaining human behaviour. The authors have exceeded their intellectual authority – they are skilled at analysing “closed” economic problems (where the boundary can easily be defined), but don’t seem to appreciate that tackling global warming is an “open” problem. I’m particularly astonished at this given their background as behavioural economists – I can hardly believe they are not aware of the concept of “bounded rationality“.

All Burkeman does is lamely point out that:

“The primary objection to this plan, as with other ‘geoengineering’ schemes, is that there’s no predicting the unknown negative effects of meddling in such a complex natural system. And it’s strange, given how much is made in both Freakonomics books of the law of unintended consequences, that they don’t mention this in the context of Myhrvold’s plan.”

Quite. But Oliver, they can’t even deal with the known knowns, let alone even the known unknowns. You don’t need to fret about the unknown unknowns!

The geo-engineering twaddle is all a shame, as Superfreakonomics apparently argues that:

“The problem with trying to reduce carbon emissions … is that the incentives are all wrong. Too many of the benefits are ‘externalities’, from which the people making the sacrifices will never benefit – and the whole history of economics demonstrates that such completely unself-interested behaviour is impossible to implement on a large scale, especially when so many people suspect that their sacrifice would not, in fact, make a significant difference to the outcome.”

I wouldn’t underestimate the potential of peer-pressure – as Burkeman puts it, “our self-interest can include a desire for the warm glow of acting in a moral or charitable way” – but I doubt this will be enough. Surprisingly, Burkeman doesn’t press this argument against the economists – whose profession has been known to not fully understand that there IS such a thing as society – but tails off into incoherence after noting that:

“This, of course, is desperately tricky territory. My immediate personal response is that Levitt’s view is irresponsible defeatism, which I find repugnant.”

“Repugnant”???!!! I’m with Levitt here. We all need to grow up and face facts.

Don’t squirt SO2 into the sky because, if this is the level of intellectual debate on how to deal with global-warming, all I can say is that we need the heavens to help us! (If I may be permitted to pluralise in a cryptic nod to Battlestar Galactica – buy the box-set if you don’t know what the frak I’m on about!).

About a week ago I was browsing David MacKay’s excellent resource, “Sustainable Energy – without the hot air“. This, and a brief conversation earlier the same evening, had started me pondering (again) on the thorny topic of CO2 uptake by the oceans. Specifically, I wanted to make some progress towards answering the question:

“If we reduce the level of CO2 in the atmosphere from its present 390ppm or an even higher level in future, will the oceans release CO2 they are currently absorbing (about 2GtC/year)? And, if so, over what timescale?”

Professor MacKay includes a chapter (31, The last thing we should talk about) on geo-engineering. He notes:

“If fossil-fuel burning were reduced to zero in the 2050s, the 2Gt[/yr] flow from atmosphere to ocean would also reduce significantly. (I used to imagine that this flow into the ocean would persist for decades, but that would be true only if the surface waters were out of equilibrium with the atmosphere; but, as I mentioned earlier, the surface waters and the atmosphere reach equilibrium within just a few years.) Much of the 500Gt we put into the atmosphere would only gradually drift into the oceans over the next few thousand years, as the surface waters roll down and are replaced by new water from the deep.”

Now, the model I have in my head of CO2 uptake by the oceans is one of flows of CO2, rather than a chemical equilibrium. David MacKay’s comment caused some self-doubt on my part. The Professor is clearly not what we chess-players might refer to as a “rabbit”. Strong grand-master would be nearer the mark.

As regular readers will be aware, I’d reached a somewhat different conclusion to that of Professor MacKay. I concluded that the ocean will continue to helpfully take up 2GtC/yr from the atmosphere, on the basis that this may be the capacity of the processes to remove CO2 from the atmosphere.

I specifically doubted, though, that the oceans will continue to absorb a fixed proportion of our emissions, on the grounds that “the ocean ‘knows’ nothing about emissions – all it can possibly be affected by is the level of CO2 in the atmosphere.”

But this idea of “equilibrium” between the surface waters and the atmosphere suggests instead that the ocean can be considered as an extension of the atmosphere, so that if the total increase in CO2 in a year from fossil-fuel burning and terrestrial biosphere changes was (say) 6GtC, 4GtC would stay in the atmosphere and 2GtC would end up in the ocean; if it were 12GtC, 4GtC would end up in the ocean.

Now, undoubtedly there is an equilibrium between the waters at the very surface of the ocean and the atmosphere: that’s how these things work. Horrifically, I’m suddenly reminded of questioning on a very similar topic during a mock interview for university conducted by my school headmaster, who had himself written chemistry textbooks…

Anyway, undoubtedly, too, there are flows of carbon in various forms to and from the deep ocean.

The question is how we combine these idea of equilibrium and flows into a single model that will help us at least put a sign to flows of CO2 from atmosphere to ocean in various scenarios.

The consequences of a pure equilibrium would be that:

1. The ocean will continue to absorb a fixed proportion of net emissions, i.e. it will proportionally reduce the impact on atmospheric CO2 levels of future increases in atmospheric CO2.

2. As soon as atmospheric CO2 levels peak, the ocean will start to release a fixed proportion of any net reduction. i.e. it will be more difficult to get the atmospheric CO2 level back down, say to 350ppm.

On the other hand, if the true explanation is that in a (hypothetical) steady-state there is a balance between flows of CO2 from the ocean to the atmosphere and vice versa, then we need a different sort of explanation. We would have to conclude that processes that remove CO2 from the atmosphere are sensitive to a higher concentration of CO2 and are therefore proceeding more rapidly because CO2 is at around 390ppm compared to a historic level of 200-280ppm.

It’s likely that the processes controlling the interchange of CO2 between the air and the sea are sensitive to other factors, such as temperature and acidity (affected by the cumulative total of CO2 absorbed). But so far, these parameters have changed relatively little. When they do, all the evidence is that they will slow the rate of CO2 uptake by the oceans.

But the crucial point is that in a flow model, the oceans will continue to remove CO2 from the atmosphere as long as the atmospheric level is above the stable long-term level which prior to industrialisation was 200-280ppm.

To jump ahead a little, the question as to whether an equilibrium is dominant is likely to reduce to what we mean by the “surface waters”, since, at the limit, the surface of the ocean must be in equilibrium with the atmosphere next to it. In other words, how quickly does CO2 disperse away from the surface of the ocean?; and from power-station chimneys through the atmosphere to the surface of the ocean?

Looking at the rest of Professor MacKay’s chapter on geo-engineering, I couldn’t help reflect that there is a contradiction. If an equilibrium between the surface waters and the atmosphere is the dominant mechanism, then one would have thought there was little to be achieved by geo-engineering approaches to increase the absorption in a limited area of ocean (sprinkling them with calcium carbonate to absorb CO2 directly or with iron filings to encourage algal growth).

So, for the umpteenth time, I found myself referring to “the doorstop” – the AR4 IPCC Scientific report. And I can report that parts of the relevant sections of this document are virtually content-free. Now, I’ve been in situations when a lack of content has been highly desirable. The objective of some business communications, for example, is to say precisely nothing of any significance. I suggest, though, that the IPCC should not be playing this game.

Let’s turn first to section 6.4.1.4 on p.452. Here we learn that:

“There is evidence that terrestrial carbon storage was reduced during the LGM [last glacial maximum] compared to today. Mass balance calculations based on C13 [isotope] measurements on shells of benthic foraminifera yield a reduction in the terrestrial biosphere carbon inventory (soil and living vegetation) of about 300 to 700GtC…”

This doesn’t really tell us much about the mechanism of CO2 exchange between the oceans and the atmosphere, but is a rather scary fact. Warming leads to carbon leaving the oceans and being taken up by land flora. Ah, I hear you think, the trees take up carbon and the oceans release it to restore equilibrium. Sorry, Grasshopper. The trouble is that as the planet warms the level in the atmosphere goes up as well. This suggests to me that the oceans do indeed release carbon as the planet warms. It’s not pull by the “trees”, but push by the “seas”.

As I said, this is a rather scary fact. Given that the planet is warming rather rapidly. And that the exchange of carbon between atmosphere and oceans takes place at the surface. Where it’s warming. The fact that the deep ocean takes millennia to cool is not really relevant. Hmm, maybe I’ve jumped ahead again.

But back to the story.

Turn now to p.446 of the IPCC report, where we find Box 6.2: What Caused the Low Atmospheric CO2 Concentrations During Glacial Times? (Seems an odd way to phrase it, as glacial times are the norm, but let’s go on!). The answer is no-one really knows. (Actually, the answer to the IPCC’s question is easy: in glacial times the atmospheric CO2 level is so low it limits photosynthesis, so we should really be asking: What causes higher CO2 levels in interglacials?). Still, no-one really knows. Or as the IPCC put it:

“In conclusion, the explanation of glacial-interglacial CO2 variations remains a difficult attribution problem.”

There’s one proviso. There’s a speculative theory (no more than a hypothesis, really) that increased amounts of dust containing iron cause increased phytoplankton growth which causes the ocean to take up carbon from the atmosphere. I mention this because the complete line of reasoning is that colder conditions cause less plant growth, that is more deserts from where dust can blow… This would restore the idea of a “push” by the land – more trees, less dust leads to more carbon in the atmosphere. The trouble is that there’s no evidence that this mechanism could explain more than a small proportion (if any) of the observed changes in CO2.

So much for the top-down approach.

Is our understanding of the physical processes any better?

Let’s see how far we can get. The IPCC Science report notes in section 7.3.1.1 (p.514) that there are 2 “pumps”, i.e. processes that remove CO2 from the atmosphere:

1. The solubility pump – dissolving CO2, giving carbonic acid:
CO2 + H20 <—> HCO3+ + H+ (1)
buffered by carbonates (e.g. CaCO3, calcium carbonate):
CaCO3 <—> Ca++ + CO3– + HCO3+ + H+ <—> Ca++ + 2HCO3+ (2)
(see a previous post for how this might be helped along by dumping some more chalk in the sea).

2. The biological pump whereby phytoplankton (algae) takes up carbon as it grows.

The IPCC note that:

“Together the solubility and biological pumps maintain a vertical gradient in CO2… between the surface ocean (low) and the deeper oceans (high)…”

[my emphasis]

This is where this whole topic starts to do my head in. How can it be that there is less CO2 at the surface, yet the oceans are taking up the CO2 we’re emitting through burning fossil fuels and forests?

Obviously there is a circulation in the oceans. The IPCC note (we’re still on p.512) that:

“In winter, cold waters at high latitudes, heavy and enriched with CO2… because of their high solubility [sic, I don't know what they're trying to say either], sink from the surface layer to the depths of the ocean. This localised sinking, associated with the Meridional Overturning Circulation (MOC)… is roughly balanced by a distributed diffuse upward transport of [CO2] primarily into warm surface waters.”

This exchange of dissolved CO2 – lots coming up, rather less going down – constitutes the “solubility pump”, but the biological pump, which, remember, involves organisms taking up CO2 near the ocean surface – effectively from the atmosphere – only operates downwards.

So here’s what I think is happening: there is still a net release of CO2 from the solubility pump, but less CO2 is released now that atmospheric CO2 is around 390ppm compared to when it was lower (280ppm say), because of simple equilibrium chemistry. This assumes there is plenty of carbonate about to stop, through equilibrium (2), the oceans becoming more acidic, reducing CO2 uptake by pushing equilibrium (1) to the left.

So whereas previously with CO2 at 280ppm, the solubility pump would have released (say – these are hypothetical figures) 4 GtC/yr and the biological pump taken 4GtC/yr back to the ocean depths, now, with CO2 at 390ppm, the solubility pump might be releasing only 2GtC/yr but the biological pump is still taking up 4GtC/yr. Hence the net 2GtC/yr uptake by the oceans which is in large part saving us from ourselves.

Digression: I have to say that I can’t help making the observation that the solubility pump depends on the MOC, and that there are those who think the MOC might eventually fail, driven as it is by the cooling of surface waters flowing from low to high latitudes (the IPCC discusses this in Box 5.1, p.397). This would, according to my reasoning, lead to a decrease in the release of CO2 via the solubility pump, increasing the net uptake of CO2 by the oceans, though this may be offset if the biological pump is also weakened (by a reduction in nutrient upwelling, say). I am therefore hypothesising a mechanism (a negative feedback) helping to cause interglacial warming periods to be self-limiting. I should point out, though, that this is completely the opposite of what the IPCC say (e.g. sections 7.3.4.1 and 3 to 5, p.530 and 532-3 and 7.3.5.4 on p.536). Digression over.

Let’s summarise where we are: I am suggesting that the equilibrium between CO2 in the atmosphere and in the oceans is potentially important. Even though the oceans release CO2 through this mechanism, the equilibrium chemistry means they release less as atmospheric CO2 rises.

But how much less?

I mentioned at the outset that it is not in dispute that CO2 is in equilibrium between the air and the water at the surface of the ocean. But how deep is the surface? What is the gradient in CO2 concentration away from the surface of the ocean? How much extra CO2 can be taken up (or as we have seen how much less released) in a year? Is the mechanism saturated at 2GtC/year as I assumed when I reported on my home-made carbon-cycle model?

It’s when we try to answer these questions that the IPCC Science report becomes – how shall I put it? – a little disappointing.

We turn now to Chapter 7: Couplings Between Changes in the Climate System and Biogeochemistry. In section 7.3.4.1 (p.528) we “learn” that: “Equilibration of surface ocean and atmosphere occurs on a time scale of roughly one year.” My school headmaster would have a fit! This sentence is indeed content-free. There is no definition of what is meant by “surface ocean”. Is it 1mm, 1m or 100m? Until we can answer this question we are unable to quantify the effect of the “solubility pump”.

Back to chapter 5. Section 5.4: Ocean Biogeochemical Changes includes some interesting diagrams (p.405) showing how “anthropogenic carbon” is dispersed in the oceans. These show that carbon levels are most elevated, compared to pre-industrial levels, in the top 200m or so of the oceans – “more than half of the anthropogenic carbon can be found in the upper 400m” (p.404) – and in the North Atlantic.

The trouble is, we’re no nearer answering the question as to how long we can consider it takes to renew the active layer of the oceans that exchanges CO2 with the atmosphere.

Let’s try another tack. Let’s say (generously) that the layer is 100m, on average, based on inspection of CO2 diffusion diagrams in the IPCC report. Let’s say it takes 1000 years for the oceans to completely turn over – a figure noted a few times by the IPCC. If the oceans are 5000m deep (on average) as shown in the IPCC figures, then the 100m “surface layer” is renewed every 50th (100/5000) of 1000 years, that is every 20 years.

Now we can try to answer the question posed at the start:

“If we reduce the level of CO2 in the atmosphere from its present 390ppm or an even higher level in future, will the oceans release CO2 they are currently absorbing (about 2GtC/year)? And, if so, over what timescale?”

The answer depends on the timescale we are looking at:

1. If we reduced the level of CO2 in the atmosphere overnight (more realistically by say 1ppm from one year to the next), then the surface layers of the ocean will release some carbon as it re-equilibrates with the atmosphere.

2. But if, more realistically, we reduce the level of atmospheric CO2 from one 20 year period to the next, we can consider the outcome as follows:
- in both 20 year periods the ocean will outgas the same amount of CO2 from the deep;
- in the first period the ocean will carry away more carbon (or release a little less) than in the second period.
There is no correlation between what happens in the second period and in the first.

3. After a millennium or so, the ocean might release more carbon because of the extra carbon it is absorbing now. On the other hand, more carbon may simply end up in sediments.

Conclusion: The oceans will not release a significant proportion of the anthropogenic carbon they have absorbed since industrialisation if we reduce the level in the atmosphere back to 280ppm over a century or two.

“Equilibrium” and “flow” models of oceanic carbon uptake are relevant over different timescales. The flow model is applicable to decades and centuries, the equilibrium model to years and (possibly) millennia.

I believe it is inaccurate to say, as David MacKay does, that:

“If fossil-fuel burning were reduced to zero in the 2050s, the 2Gt[/yr] flow from atmosphere to ocean would also reduce significantly.”

The increase in annual oceanic CO2 uptake due to the difference between CO2 levels in the atmosphere and the ocean is partly due to the difference between CO2 levels now and when the current surface waters were last exposed to the atmosphere, that is, the difference between 390ppm and 280ppm approx. and partly due to the difference between the CO2 level compared to the previous year – about 2ppm. If (as I’ve assumed) 1/20th of the surface waters are renewed each year, we should allow 1/20th of (390-280)ppm, that is 5.5ppm as the comparable CO2 concentration difference. 5.5 is several times 2, so the dominant cause of net oceanic CO2 uptake at present is the renewal of oceanic surface waters, not annual increases in atmospheric levels of CO2.

In other words, when Professor MacKay goes on to say:

“Much of the 500Gt we put into the atmosphere would only gradually drift into the oceans over the next few thousand years, as the surface waters roll down and are replaced by new water from the deep.”

he is correct – this process is going on. But, I suggest, it accounts for at least 75% of the 2GtC/yr of our CO2 pollution that the oceans are helpfully soaking up for us.

And if we were to reduce atmospheric CO2 levels by say 1ppm/year (e.g. by ceasing fossil-fuel burning and enacting a programme of worldwide reforestation), oceanic surface re-equilibration would reduce the annual decrease by only about 10%, and with atmospheric CO2 at its current level, and all else being equal (unfortunately it probably won’t be), the solubility pump performance attributable to oceanic surface water turnover will continue to remove around 1.5GtC/year (about another 0.75ppm).

To go on, reducing atmospheric CO2 concentrations at a rate of 1.65ppm (based on the above figures), reducing to 1ppm as we approach the pre-industrial equilibrium, would allow us to return from 450ppm to 280ppm in around 170/1.325 [(1.65+1)/2] or around 130 years.

[Though, as I said, all else is not equal and positive feedbacks due to warming of the oceans and decreased albedo because of loss of ice-cover, etc. will most likely increase this timescale significantly.  On the other hand, if we do it before the deep ocean has warmed, we might just save the planet!].

When someone says, literally, or in effect: “Listen to me, I’m a Professor”, be suspicious, very suspicious.  Because the truth is, Professors are just as likely as the rest of us to spout misleading garbage.  But their gibberish is more likely to be published, simply because the average editor thinks: “Letter from a Professor – must be worth a column inch or two!”  If you’re told it was written by a Professor, the chances are therefore higher than otherwise that what you are reading is poorly thought-through drivel.  Furthermore, having their output published more often provides the said Professors with the positive reinforcement that encourages them to submit for publication more material in the same vein as the rubbish that shouldn’t have been published in the first place.

I was therefore immediately sceptical when I read the last of an interesting clutch of letters in this morning’s Guardian on the topic of the UK’s procurement of new trains.  A Professor Lewis Lesley of Liverpool wrote:

“At £5.4m per carriage, these are the most expensive trains ever. For the same money, 30,000 high-speed luxury motorway coaches could be acquired, increasing the total size of the UK bus and coach fleet by 50%.”

I think he means that you could get 30,000 coaches for the £7.5bn cost of the whole order, not for £5.4m.  The order is for 1,400 train carriages, plus locomotives, so, including the cost of the locomotives (expensive, because they’re dual diesel/electric) one train carriage costs as much as around 21.5 coaches.  Hmm, maybe that’s not too unreasonable.

But, still, 5.4 million pounds – wow, that’s a lot of money!

Or is it?

Let’s assume, for ease of arithmetic, that the carriages seat 54 people each on an average trip (it’s probably more, since they’re filled like aeroplanes these days).  So that’s £100,000 per seat.  Wow, still a lot.

Wait a sec.  These carriages will be in service for decades.  Let’s just give them 20 years (they’re actually expected to last nearly twice as long as this, but, as you may have guessed by now, I like to make conservative estimates *).  Now we’re down to £5,000/seat/year.

See what I’m driving at?

Divide just once more and we see the cost is less than £15/seat/day over the 20 years.

And, of course, these trains can make, let’s say, two return trips (another conservative estimate) on one of the UK’s main lines every day.

So, for a single journey – London to Manchester, say – the portion of your ticket price needed to cover the investment in the rolling stock is at most a princely £3.75.

Think about that next time you shell out as much as £360 for a walk-on ticket, as the Guardian’s consumer champion reported on Saturday.

There was a reason why I scrutinised Professor Lewis Lesley’s “argument”.  I would much prefer a future where I am able to travel around the UK on high-speed trains than “high-speed luxury motorway coaches”.  This is a contradiction in terms: “luxury” and “coaches” do not belong together in the same sentence.  And virtually every vehicle on the UK’s roads is capable of exceeding the 70mph speed limit.  Only an idiot (or perhaps a Professor) would contemplate purchasing a fleet of coaches incapable of sustaining 70mph.  What the adjective “high-speed” is doing in the Professor’s sentence is therefore anyone’s guess.

Look, travelling by coach is an unpleasant experience.  That’s why, by and large, you find, proportionally-speaking, considerably more impoverished students on coaches and highly-paid Professors on trains.

It was when he started on the merits of promoting coach travel (in some unspecified way – presumably state diktat) that George Monbiot lost me in his (nevertheless worthwhile) book Heat.

Look, guys, if you’re going to get everyone out of their fossil-fuel powered cars and aeroplanes, then please, please provide an alternative vision that people can believe will improve their lives.  Heck, why not try to capture their imagination once in a while?  Because you’ll never get enough people to wear a hair-shirt.

Oh, and I agree with the Guardian’s correspondents who say we should be completing the electrification of the rail network, not buying diesel locomotives.  Getting rid of the need for dual-powered trains would also reduce the cost per carriage-seat even further, of course.

In fact, of course, the main costs of your rail (or coach) journey are fuel, staffing and maintenance of the infrastructure (not necessarily in that order), the last two of which are subject to economies of scale, so that the cost of rail travel should start to reduce if you can get the network into a dynamic of continued expansion of passenger numbers.  If the railways are run on renewable electricity, then in the long-run, the fuel cost will come down, because the cost of generating the energy will ultimately be subject to the scale economies of manufacturing.

Of course, the most significant cost to society of train or coach journeys is most likely the passengers’ time.  Perhaps this should be borne in mind by Professors making the recommendations on which Government transport policy is no doubt based.

—–

* Another way of looking at this is that the cost of the capital (think of it as a mortgage) to pay for the carriages would be something of the order of 5% pa – another reason for choosing the figure of 20 years for the lifetime of the carriages.

…as the French say (sorry about the lack of a cedilla there).

A New Year resolution was to blog about any interesting news stories first thing.  But, plus ca change…

At the start of 2009, though, perhaps I may be forgiven for wondering in what areas of our lives the record is broken and where there really is a trend.

Take the financial crisis.  I sense a worm has finally turned.  There’s a growing caucus bold enough to argue that it isn’t all the fault of bad people (the causes of socio-economic disasters are never quite so simple).  Rather, trade imbalances – the dangers of which many have been warning for years – are the root cause.  So says Hank, and I presume Win alluded to much the same thing, though the Times’ report of his Radio 4 interview focuses on the bankers rather than the rest of those at fault (such as those responsible for overseeing the financial system perchance?).

Whilst the discourse around this crisis may be entering a new phase, I very much doubt we’ll avoid similar mistakes in future.  The FT article reporting Paulson’s thinking concludes:

“…avoiding crises in future will require global macroeconomic co-operation as well as better financial regulation and risk-management.”

This “global macroeconomic co-operation” is simply not going to happen.  Pie, meet sky.  If governments instead concentrate on defending their own economies against the positive feedbacks that have turned a US property debacle into Great Depression 2, then we’ll have a much better chance of avoiding GDs 3, 4 and 5.  We’re not going to eliminate booms and busts anytime this century or next, but focusing on minimising the effects – such as the knock-ons from personal and corporate bankruptcies – will help break the cycle of fear that exacerbates the situation.  A little more equality would also help.  In particular, enacting policies to prevent the wages of the low-paid ever again getting so out of line with their housing costs would provide more of a buffer against personal and systemic economic crises.  Hopefully a lot more will be said on this topic in 2009!

I sense, too, that in 2009 more of the political heat in the UK will be directed at Gordon “Superhero” Brown and – perhaps this is wishful thinking – the insufferably smug and incongruously arrogant (in that he doesn’t have anything to be arrogant about) Alistair Darling.  Away over the Christmas period, I was able to access the BBC’s World News channel (why are all the BBCs channels not on cable here?) and caught the interview Darling gave to a sycophantic Robert Peston.  Apparently Freddie G said the Government’s discussion was “less of a negotiation and more of a drive-by shooting”.  Spot on!

How dumb it now looks to be fining the UK banks with (among other things) 12% coupons on prefs. (a lot more than elsewhere, as DeAnne Julius observes).  This doesn’t increase their capital, it decreases it, since the first thing they’re going to do with any profits is pay off this particular debt.

I’ve just started reading Niall Ferguson’s The Ascent of Money.  (And a New year’s resolution is to actually finish it before starting something else).  He makes the point in his Introduction that he aims to improve financial literacy.  Laudable, but doomed.  After a spike of interest in the operation and pathologies of the global financial system, the current crisis will be forgotten, and the next generation will make similar mistakes.

The travails of the global economy has pushed global warming (GW) from the headlines.  But there is more chance of awareness helping solve GW, which is a one-time phenomenon (though there will no doubt be other even slower-burning environmental disasters to deal with).  I don’t agree with the scientists who, according to the Indy, apparently believe we need to start creating new problems.  Didn’t their nursery school teach them the folly of swallowing a spider to catch a fly?

We’re still at the stage of building a consensus for action.  Thinking is progressing, for example, in another book I’m reading (remembering my resolutions!), Oliver Tickell’s Kyoto2.

But something has changed. Global economy, global warming… Anyone spot a pattern here? Maybe 2008 will be remembered as the year the world really became global.

Then there’s the war in Gaza.  2006 revisited?  Not really.  The political climate is different – as if the fever of El Nino has given way to the chill of La Nina.  As we were reminded in Georgia in August, propaganda is now a key determinant of the outcome of these nasty little local difficulties.  Israel realises this, and has raised its game, seemingly with some effect.  Hamas’ position is untenable.  Continuing to fire rockets at Israel, while hoping an international outcry over humanitarian concerns will prevent Israel from achieving its objectives on the ground, allowing Hamas to claim a victory now, like Hizbullah back in the day, simply isn’t going to work this time. C’est pas la meme chose. Hamas will condemn the Gazan people to a nasty winter on CNN if it continues on its present path.

On the other hand, as I remember my MP wisely pointed out last year, there is scant hope for a change in the bigger picture in the Middle East, unless Obama can perform some kind of miracle.   Robert Fisk appears to be a commentator who knows what he’s talking about: cynical he may be, but unrealistic he is not.

What with war in Gaza and the house-price bubble in reverse, it does seem we’ve returned to 2006.  Not only that, Russia is messing with gas supplies to Ukraine.  Again.  But what’s their game?  This isn’t a record that can go round and round.  Every time Russia plays this card it becomes less effective.  Their customers accelerate their efforts to diversify supply and to build facilities to store fuel.  By the sound of it, Ukraine is less over a barrel (or should I say cubic metre!) than in 2006, and can last out for a while.  And if Ukraine ends up paying West European rates for gas, Russia has no lever at all.  You’d think the Kremlin would keep its powder dry.  Or is this latest spat leading to something more serious?

Tricky business, trying to work out what is really changing and what is simply a repeat of the past.

Here’s one observation, though.  Maybe some of the power of the British media is ebbing away.  I refer not to the John Sargeant affair, but to the SBBC Sports Personality of a vintage Year.  To my delight, Chris Hoy won by a landslide, but apparently was not the favourite:

“Hoy, who became the most successful male Olympic cyclist of all time after winning three gold medals in Beijing, said he was ‘absolutely stunned’ to be named BBC Sports Personality of the Year, after recording almost 40% of the public vote. In beating the favourites, Lewis Hamilton and Rebecca Adlington, into second and third place, he overcame one of the strongest fields in the prize’s 55-year history.”

Look, a simple opinion poll could have shown this would happen.  Believing Hamilton would win the award by a lap or two, sections of the media seemingly set out to promote Rebecca Adlington as a rival.  But the British public is not stupid.  Sure, Adlington did a Dame Kelly, winning 2 golds, but Hoy bagged 3 – the first Brit to do this since 1908, FFS – not to mention one in 2004.  Hmm, let’s think about this one, shall we…?

A final thought is that maybe 2008 will prove to be a watershed year, when Britain stopped being a nation of sporting losers.  But don’t bet on it.  Not until after the Ashes anyway!

Yes, finally the Ofcom has spoken. Not very loudly, it seems. It’s really just a rap on the knuckles for “The Great Global Warming Swindle”, largely because:

“…whilst Ofcom is required by the 2003 Act to set standards to ensure that news programmes are reported with ‘due accuracy’ there is no such requirement for other types of programming, including factual programmes of this type.”

Unbelievable. What planet are they (or rather the legislators responsible for this insanity) on? One that is going to get a hell of a lot warmer, it seems, if we can’t work out how to make rational, science-based decisions. How can the category “factual programmes” even exist without “standards [of] due accuracy”? Has anyone thought about what the word “factual” actually means??

Remind me if I don’t return to this argument later on, but to state the thesis briefly, in complex domains, problems – whether big ones (like GW itself), or small ones, like “Swindle” – almost always have many causes. Dealing just with the immediate cause may be futile. In the case of “Swindle” it may be most effective putting effort into changing the rules of the media game, rather than engaging in trench warfare. Because, if the ultimate arbiter of truth is not factual accuracy then we just end up with a popularity contest. Hey, why not incorporate audience votes in science programmes? Phone-in to vote for your favourite theory of gravity!

Luckily, in the case of “The Great Global Warming Swindle”, the programme:

“…broke rules on impartiality and misrepresented the views of the government’s former chief scientist…” even though it “was ‘on balance’ cleared of ‘materially misleading the audience so as to cause harm or offence’”. (Quotes from the Guardian’s news story on the findings).

But what if they hadn’t broken any rules?

And at least in this case George Monbiot got his retaliation in first, with a comment (and CiF) piece in today’s Guardian, as well as an essay in G2. [Illustrated with the usual photographs, incidentally: someone should devise a market instrument for investors in pictures of power stations, melting ice and - my personal tip - pictures of solar panels and photogenic children in Africa. Oh, sorry, it slipped my mind for the minute that markets are in the dog-house right now.]

George does an excellent job, as usual, in his forensic G2 piece (though there’s a touch of conspiracy theory in his analysis of Channel 4) but in the very last column it all falls to pieces. [See yesterday's post for my views on conspiracy theories and the need to read the detail - in this case right to the end - to avoid Taleb's randomness illusion]. Even so, I urge you to read George’s dissection of “Swindle”: you may be surprised. I recollect that I had moreorless bought into the idea (which Monbiot debunks) that Thatcher’s espousal of GW science was partly due to her search for weapons to use against the UK’s coal-mining industry.

Remember, though, that, as well as the particular pathology – in this case the way “Swindle” was given a platform – we also need to look at the underlying causes.

This is where a major problem lies in George’s piece:

“[Channel 4] says [its scheduling of "Swindle" and other programmes] ‘is against the background of the IPCC [Intergovernmental Panel on Climate Change] stating that there is a 90% certainty that the causes of global warming are man-made, it follows that there is a 10% uncertainty. Yet this 10% uncertainty receives a disproportionately small amount of airtime.’ I [George continues] find this argument extraordinary. A 90% level of confidence does not mean that 10% of the evidence suggests that an effect is not occurring — in fact, there is no reliable evidence showing that man-made global warming is not taking place. It is expressed in this way because there is no absolute certainty in science. The ‘very high confidence’ the IPCC expresses in the global warming thesis is the strongest statement any reputable scientist would make about his area of study. It is legitimate and right to stress that there can be no absolute certainty about global warming.” [my italics stress].

90% is not in fact a very high probability when we are discussing scientific findings. In my opinion, it would be more than justified to say that we’re “virtually certain” that “man-made global warming is [...] taking place”, and by virtually certain I mean at least 99%. A 99.9% claim would be perfectly reasonable. So why does the IPCC not say this? Saying 90% gives the green light to people like Martin Durkin (the maker of “Swindle”).

I’ve just done a bit of weight-training and consulted the IPCC’s latest massive report (The Fourth Assessment Report, or “AR4″). If we look at Table 1 on pages 120-1 of the Scientific Basis (there are 3 parts to the overall report) we see that, although the IPCC is happy to use the words “virtually certain”, it only does this when a result “can be estimated probabilistically”. For example, a particular set of data may have a definable probability of indicating a trend.

[Note that our ability to calculate such statistics requires us to make assumptions about randomness - i.e. a bell-shaped curve or Gaussian distribution. This implies that we have a theory about the causes of variation in the data in the first place! For example, if we say we're 99% certain that the glaciers are melting this finding must have been calculated against a null hypothesis that changes in glacier volume are subject to random fluctuations. This may not be true. There could be reasons we are entirely unaware of for all the world's glaciers to either melt or grow at the same time (on top of reasons for correlation between glaciers in the same region which have presumably already been taken into account). Such "unknown unknown" correlation would invalidate the null hypothesis and hence the 99% "virtual certainty". If we're 99% sure what the data tells us, then surely we must be at least 99% sure of our theoretical understanding. I'm sure Taleb would agree with me! It's entirely illogical to have more faith in data-driven findings than in any aspect of the underlying theory explaining them! But this is not my main point today.].

No, what baffles me is why the IPCC restricts itself to a maximum of “very high”, that is, 90%, confidence when it comes to “scientific understanding”.

Politics may have played a part in the IPCC process. Some governments may have lobbied for 90% rather than 99% as the maximum possible confidence. But let’s put that to one side. I want to argue that a critical factor is widespread misunderstanding of the scientific process.

Practising scientists often cite the philosopher Karl Popper. They understand that theories can be “falsified”. Some may even have heard of Thomas Kuhn and appreciate that such “falsification” takes place in “scientific revolutions”.

But what happens in such revolutions? In fact, scientific theories are superseded rather than “falsified”. Let’s consider one or two examples very briefly. When Einstein “overturned” Newton’s theory of gravity he didn’t demonstrate that Newton’s equations were wrong. Rather, he showed the limitations of Newton’s theory. Crucial experiments (where the difference was large enough to be measurable) showed that Einstein’s theory made more accurate predictions than Newton’s. In effect, Einstein incorporated Newton’s findings in his own theory of gravity. Albert never said: “Silly old Isaac’s made a mistake there.”

A case closer to the topic in question is the oft-cited theory of the 1970s that we were about to enter a new ice age. Now this theory hasn’t gone away. The Earth would be cooling (though there is debate as to when the next ice age would occur), if it weren’t for global warming. The current theory of global warming includes the ice age cycle as well as all other prior theories for the variation in the Earth’s climate, such as the effect of volcanic eruptions. Quantitative statements about man-made global warming take into account numerous other causes of climate variation.

Now, it’s possible to imagine reasons why the Earth might not warm as much as projected. For example, the solar system could enter some as yet undetected dust cloud. But any quantitative estimates of the effect of such a dust cloud would have to include the effects of man-made GW. And if the planet cooled dramatically as we entered the dust cloud we’d still have to worry about its temperature rising beyond today’s level because of our greenhouse gas emissions when we came out again. Just the same as, if we solve the problem of global warming and get the climate back to something resembling its pre-industrial state, we will – over the longer timescale of millennia rather than decades – need to take account of the Earth’s ice age cycle which was apparently of such concern in the 1970s.

There are examples in science of theories that are (or could be) flat wrong. But these are theories for which there is no evidence or for which the evidence has been misinterpreted due to problems inherent in the data-gathering process. This is most likely when observations are difficult, such as at the frontiers of physics. For example, the infamous string theory could be wrong because it makes no new predictions.

Any replacement for a theory with lots of firm data, such as global warming, would have to provide explanations for all that data. Clearly this is easiest if the new theory explains the old theory as a special case, rather than by invalidating it entirely.  In the history of science theories are almost always shown to be incomplete rather than “wrong”.  In my opinion, Imre Lakatos understands this process most clearly, even though this aspect of his ideas is rarely stressed.

The probability of the theory of global warming actually being wrong is therefore vanishingly small.  Our level of certainty is, in fact, far more than 99%.

So one of the underlying causes of programmes like “Swindle” is that even the scientific establishment is unclear as to the nature of its theory. Even if there are unknown unknowns and the planet does not end up warming over the 21st century and beyond this would not in itself invalidate the theory of global warming.

The IPCC AR4 Scientific Basis report is a real goldmine of information, even if it isn’t perfect, as I recently pointed out.

As I discussed in a previous post, an idea I later developed a little, policies to address global warming must rely on an understanding of how natural systems will respond to the increase in atmospheric CO2.  Will the oceans keep absorbing a couple of GtC worth of CO2 each year (as estimated since 1990 – AR4, p.26, as referenced previously) or more (as implicitly assumed by many) or less?  And will land ecosystems manage to take up more or less carbon than in the past?  Especially if we continue to reduce the area of ecosystems able to do this – since agricultural land clearly does not progressively store carbon.

I’ve been looking at a critical section in AR4 on ocean uptake of CO2.  This is 5.4.2.2 on p.403-5 (though the main section on the carbon cycle is 7.3, p.511 ff).  I quote:

“The fraction of net CO2 emissions taken up by the ocean (…) was possibly lower during 1980 to 2005 (37% +/- 7% [that is, 118 +/- 19 of 283 +/- 19GtC of emissions]) compared to 1750 to 1994 (42% +/- 7% [that is, 53 +/- 9 of 143 +/- 10 GtC of emissions)...  The decrease in oceanic uptake fraction would be consistent with the understanding that the ocean CO2 sink is limited by the transport rate of anthropogenic carbon from the surface to the deep ocean, and also with the nonlinearity in carbon chemistry that reduces the CO2 uptake capacity of water as its CO2 concentration increases".  (my inserts in [ ]’s – based on Table 5.1, p.404).

And we also have to worry about “a decrease in CO2 uptake capacity” as the ocean warms.

On the other hand section 7.3.2.2.5 (p.521) notes that:

“The ocean uptake has increased by 22% between the 1980s and 1990s, but the fraction of emssions (fossil plus land use) taken up by the ocean has remained constant.”

though of course the ocean “knows” nothing about emissions – all it can possibly be affected by is the level of CO2 in the atmosphere.

We really need to get a handle on what the oceans are going to do in the future since it makes such a huge difference to the level of carbon emissions we can get away with.  It’ll be the first section I turn to in AR5.  As AR5 is due around 2012 (I suppose), maybe we should have a think about where we focus scientific resources now…

OK, it’s not quite up there in the tongue-twister stakes as my best creation: “We’re wearing weird red wellies”. Try saying that quickly after a few pints!

About 10 days ago my Sunday morning was spoilt by the sight of the really rather scary, formerly reassuringly plump (maybe he’s become a vegan) ex-Chancellor of the UK Exchequer Nigel Lawson on Andrew Marr’s weekly political couch-fest. Why had he crawled out of his coffin? Well, to plug his book, of course. It is indeed one of the world’s great mysteries why the BBC is so careful not to mention products by name (to utter “Coca-Cola” without permission would be blasphemous in Beebland), yet so shamelessly allows so many people to promote their products. The occasion of Ryanair’s financial results, for example, seem to provide a free 1 minute advertising slot for Michael O’Leary. I’m surprised he doesn’t move to quarterly reporting.

Presumably, if you have good PR help, a public profile or the right connections, you can get as much time to plug a book on the BBC as you want, because, blow me down if I didn’t hear Count Lawson again on the radio a few days ago, on some type of pick of the week show on Radio 4. At least he was being grilled this time – listen and learn, Andrew Marr. But surely there should be some criteria for whether a book is worthy of BBC airtime? E.g. positive reviews by experts in the field?? Tricky, but how could anything be worse than the apparent old school tie basis of selection we have today?

Get this, Lawson’s book was turned down, he said on TV, by 7 UK publishers, but he has a “good agent” who managed to get it published overseas. Makes you wonder if it’s really worthy of promotion in the mainstream media, don’t it? I was therefore going to put TV bottom of the list of reliable science sources.

But then I read the Times’ review of Nigel Lawson’s contribution to the debate. Astonishingly, the reviewer, an Alexander Cockburn, chides Lawson for accepting the anthropogenesis of global warming! In fact, Cockburn’s review leaves me with the impression that Lawson may be saying something useful. A view dispelled by a somewhat more comprehensive (family connections?) review in the Spectator. Lawson, it seems (before I rush out to buy his work), doesn’t deny global warming, he merely downplays it, in order to argue against doing anything much at all (I’ll be more specific when I’ve read the book – which I will likely do, because, unfortunately, publicity grants de facto credibility, requiring a response). Insidious.

So, let’s award 0/10 for the informativeness of the mainstream print media (Times) and 1/10 for the broadcasters (BBC), who at least attempt to be impartial. Let’s give general current affairs (Spectator) 2/10. And let’s give published works 3/10. At least the publishers tried to stop Lawson, if to no avail; perhaps his memory of the Spycatcher affair stood him in good stead.

Now, compare this piece by Gwyn Prins from the Guardian’s Commentisfree site. For all I know, Gwyn Prins makes similar points about the ineffectiveness and counterproductivity of existing policy responses to GW as does Nigel Lawson, but at least he does not base his argument on false premises. In fact, I was interested enough to download Prins’ paper “The Wrong Trousers: Radically Rethinking Climate Policy” (written jointly with Steve Rayner). Prins & Rayner argue that GW is serious and urgent, but the Kyoto mechanism ineffective. They therefore advocate “enlightened self-interest” (ouch!). Still, a step forward from the “downplaying” strategy of a failed UK Chancellor (the Lawson Boom was followed by an inflationary bust – anyone else notice a pattern starting to develop? – let’s ignore problems until it’s too late, shall we, Nigel?).

So, let’s say 4/10 for op-ed (as the Yanks call it), and 5/10 for online publications.

But what I want to draw attention to are the exchanges in the comments on Prins’ piece. First, let’s backtrack a little. Lawson (like Nigel Calder) apparently claims the Earth is no longer warming, since annual average global temperatures have not returned to their 1998 record level. Now, as we all know, temperatures are bound to fluctuate from year to year about a long-term warming trend. All the scatter of annual mean temperatures tells us is that the annual variability of transfer of heat from the surface of the oceans exceeds the amount of heat gained by the planet each year. But, if the oceans were to cease gaining heat, without an overt cooling cause (such as a volcano) then GW theory would be in trouble – it would imply (since the oceans are so large and important in this context) that the Earth is no longer cooler than it needs to be for it to be in energy balance. Unfortunately, this is exactly what the IPCC’s 4AR implies. Yes, Fig. 5.1 on page 390 shows the oceans cooling over the last few years. Does the IPCC really explain this anomaly? No. It is “bottom-up” science – based more on observation than theory-driven.

So, say 8/10 to the IPCC. Maybe they need to put a bit more effort into the coherence of the whole package, and resolve or at least discuss these sorts of problems before rushing their 900 pages to CUP.

Anyway, I was mulling over this problemette when I noticed it discussed by PacificGatePost and deconvoluter in the comments on Prins’ Guardian piece. Phew! It turns out there was a problem with the measurements. deconvoluter refers to a Realclimate piece that gives chapter and verse.

So let’s give blogs (Commentisfree) 6/10 and specialist blogs (Realclimate) 9/10. Now we’re getting somewhere.

But there’s more. The Prins piece was in response to an article in Nature, by Roger Pielke et al arguing that the IPCC scenarios (actually I consider these unrealistic and irrelevant, but let’s put that to one side for now) are over-optimistic. The scenarios – shock!, horror! – assume some carbon “savings” will occur without specific policy to reduce emissions (um, anyone seen the price of oil today?). Now, even though the Pielke article and a Nature editorial are accessible on the internet, much of their content is subscriber only, so it does rather perturb me that so much debate (rather than actual science) is being conducted (in Scienglish) in the pages of Science and Nature. Not their fault, but what are the mainstream media doing? I believe as many people as possible need to develop their own understanding of the science and the issues. “Trust me, I’m a scientist” is only going to get us so far.

So, 7/10 in our informativeness competition to science magazines.

I gave the Realclimate site 9/10 – for trying to bridge the gap between the scientific world and normal people – but they’re not the real winner. 10/10, and the top prize goes to – yes, you’ve guessed it! – the internet itself which has made all this possible. Without it, I suggest the GW debate would be years behind even where it is now.