Uncharted Territory

November 4, 2009

Some Contrarian Climate Change Ideas

I had a day (well afternoon and evening) out of the home-office yesterday. I took the train to Cambridge and caught the first hour or so of a Cambridge Energy Forum on UK buildings before heading to the Guildhall for a well-attended public meeting on “what Copenhagen means for you”.

Maybe I’m an unreconstructed contrarian, but I find myself disagreeing with much of what I’m being told on the topic of global warming. Here are my latest musings.

What’s the target?

The Guildhall meeting started with a very competent whirlwind summary of the science of climate change by Emily Schuckburgh of the British Antarctic Survey. In particular she showed a rather longer graph than I’d seen before of historic temperatures and CO2 concentrations derived from ice-core analysis: around 800,000 years worth. During all this time the level of atmospheric CO2 had varied only between 180 and 280ppm, in close correlation with the temperature.

Furthermore, when temperatures have briefly spiked up during inter-glacials they have reached levels somewhat higher than at present (or in the entirety of recorded human history for that matter). Schuckburgh suggested temperatures may have been 4C higher than her baseline (presumably the pre-industrial average temperature, 0.8C lower than at present) for brief periods (and -8C lower during ice ages). Scary stuff.

Why then, do we think we’ll manage to keep temperatures within 2C of pre-industrial levels – and they’ve already risen 0.8C – at the sort of CO2 concentrations implied by the discussions at Copenhagen? We’re at around 390ppm right now and it doesn’t look like the proposed policies have much chance of keeping us below, at best, 450ppm.

And on top of that, CO2 isn’t the only greenhouse gas. Some have only just been invented! If we can’t get all the methane (CH4) and nitrous oxide (N2O) down to natural levels and the anthropogenic alphabet soup of CFCs, HFCs and so on down to negligible levels, then we’ll be even warmer.

Here’s my contrarian position (1): we need to get CO2 levels back down to the natural range of 180-280ppm. Presumably we’d aim for 280ppm, since 180 implies an ice age!

At present the strongest mainstream positionsupported by reputable scientists and prompted by James Hansen’s landmark paper – is that we should aim for 350ppm.

The theory – perhaps I should say hope – is that we can “stabilise” levels at 350ppm and a 2C temperature rise. This is wishful thinking poppycock. In fact, the climate system is not a stable one. In particular, it will not be stable at 350ppm and a 2C temperature increase. It will have a tendency to warm further, for example, as ice melts, darkening the planet’s surface; as CO2 levels rise further as forests burn in the occasional much hotter summers we’d experience; as wetlands dry out and release their carbon too; and as the ocean circulation gradually slows due to the reduced temperature differential between the poles and the equator, removing less and less carbon from the atmosphere as time goes on.

We’ve opened Pandora’s box – we have to put all the demons back in, not just some of them.

Will the Gulf Stream slow and keep Britain cool?

This was meant to be a post about policy, but I’ll get the other science point out of the way, since this old chestnut came up in the Q&A at the Guildhall.

The point is that the Gulf Stream (as the North Atlantic branch of the ocean’s circulation is popularly known) can be disrupted by lots of fresh water flowing into the North Atlantic. Such water floats (because it’s fresh which makes it lighter, even though it’s cold which tends to make it heavier) and would prevent the circulation whereby (salty) cold water sinks as it approaches the pole, drawing more warm surface water up from equatorial regions, keeping Northern Europe, including the UK, a lot warmer than other regions at such a high latitude.

As the world emerged from the last ice age (and previous ones), it seems vast quantities of meltwater from the North American ice-sheet poured into the North Atlantic as ice-dams gave way. This disrupted the oceanic circulation and caused warming to reverse for a while, at least in the North Atlantic region.

It’s possible that meltwater from Greenland could have a similar effect to that from Canada, but unless someone’s asleep on the job, this isn’t imminent, since we’d see the water pooling in Greenland.

So, what will happen to the Gulf Stream in the absence of disruption from a sudden flood of meltwaters?

Here’s my contrarian position (2): the ocean circulation will strengthen in the short-term (which, depending largely on future greenhouse gas emissions, is likely to be a century or two), then gradually weaken as the ice-caps disappear. There’s no get out of jail free card for the UK, certainly not in our life-times.

The point is that the circulation is ultimately driven by the temperature difference between polar and equatorial regions.

More heat is captured by the atmosphere in the tropics than at the poles, that’s why you have a circulation in the first place. With the presence of greenhouse gases, even more heat is captured in equatorial regions and tends to be transported poleward either in the oceans or the atmosphere. More warm water stays near the surface until it cools as it approaches the poles. The result is a stronger circulation.

The presence of ice (Antarctica, Greenland, permafrost) keeps the polar regions from warming. Until this ice melts, more heat will be transported poleward. Indeed, the heat uptake by ice melt that drives the circulation.

Of course, the heat transport itself progressively melts the ice. When it’s eventually all gone, temperatures will tend to equalise between the poles and the equator, weakening the circulation. We’re not there yet, though.

I should remind readers that the ocean circulation is one of the major ways in which carbon dioxide is removed from the atmosphere.
[5/11/09 Afterthought: Oops, this throwaway comment could be a bit misleading. In fact, the ocean circulation returns CO2 to the atmosphere, so, if the circulation increases in strength, as I’m suggesting it will over the next century or two, the net effect will be for the ocean to take up less CO2 (net, the oceans are currently absorbing CO2 because the ocean and atmosphere are out of equilibrium because of the “extra” anthropogenic CO2 in the atmosphere). This mechanism represents a positive feedback during deglaciation warming phases, and, if my hypothesis is correct, during the current phase of global warming. When the ocean circulation is interrupted, then there is a positive cooling feedback as the ocean releases less CO2 due to the reduced circulation, taking up more net. This could explain the persistence of cooling phases during deglaciations (warming periods after ice ages), such as the 1000 year long Younger Dryas event.].

Therefore, as I said in my first heresy, we’d better get temperatures and CO2 levels back down before the ocean circulation strengthens too much. [5/11/09: Amended this sentence, see previous note in square brackets].

Burning wood is not a good idea

Everyone loves Julian Alwood! (He taught on my MBA programme). He told an amusing anecdote yesterday about how some well-meaning foreigners had tried to introduce a more efficient stove in Malawi. The problem was Malawians bash the meat while its cooking, apparently, and the new stoves didn’t last very long.

But the main point is that the big problem in Africa is burning wood. It releases carbon (and, almost as important, retains moisture). “Reducing deforestation” (George Orwell would have loved the double negative!) was mentioned by Chris Hope, among others, yesterday as the cheapest way to avoid deforestation. What’s really needed in Africa is a robust solar stove design, but more about that another time.

So why then was a picture shown at the Cambridge Energy Forum of a supposedly virtuous Briton carrying some logs to put on his fire?

I’ve harped on about the biofuel topic on this blog previously and will no doubt do so again (see the Biofuel category in the box on the right), but here’s my contrarian position (3): Everyone should avoid the use of all forms of biomass as fuel.

Here’s something you may have missed. A radio programme a day or two ago was discussing a satellite that has just been launched to detect moisture levels from space. The point was made that if forecasters had realised that European soil moisture levels were so low in 2003 they would have been able to forecast that year’s heatwave much more accurately.

Interesting factoid. I don’t know about you, but it suggests to me that one way we could adapt to global warming here in Europe is to increase soil moisture levels. How do we do that? More trees (including decaying ones), less arable farming, that’s how. And how do we achieve that change? We ban agrofuels (the right-on term for biofuels) and discourage biomass burning. Simple isn’t it, when you think things through?

Trying to reduce UK (or other comparable country’s) energy consumption is a waste of time, effort and money

I have to say I was stunned by the facts and figures thrown at me by the Cambridge Energy Forum (and in Michael Kelly’s talk on a similar topic in the Guildhall). I think they’ll put up a report of the meeting and slides on their site, in due course, so I won’t try to cover everything that was said.

Let it suffice for me to report that improving the energy efficiency of the UK’s housing stock turns out to be a Sisyphean task. (And even if we succeeded, energy consumption would tend to rebound as we spent the money saved! I won’t go into all this again – my most recent post on the topic is here). After you’ve insulated the loft and put in the low-energy lightbulbs – and anyone who doesn’t take the simple steps is an idiot – it starts to get really expensive.

And you can’t wait for new low-energy houses to be built to replace the existing housing stock because that would take 20,000 years. Or something.

The UK will not reduce its energy consumption by 50%. It won’t happen. The effort is futile. It’s a dead parrot of a policy.

The reason is economics. Importing solar-generated electricity can be achieved at a fraction of the cost per kWh. Promoting that sort of scheme is what everyone should be putting their effort into. And the Desertec plan was only mentioned once, en passant, in the Guildhall.

And then there are the economic reasons. People want to be richer, not poorer. They don’t want to be turning their thermostats down. And what’s more, people are tending to get richer over time – despite a raft of policies promoted by governments round the world designed by a secret global committee with the objective of halting this process – ultimately because technological (and learning) advances mean productivity tends to steadily increase (especially when regular economic recessions purge the least efficient).

The fact that more people are getting richer all the time suggests that policies based on changing people’s behaviour through taxation have had their day. We need to think again about behavioural taxes on everything from alcohol to carbon.

The main advantage (probably the only one, at least in this contrarian’s view) of a carbon tax (championed by the even more lovable Chris Hope last night), or any other way of pricing carbon, is that it makes dirty energy more expensive than clean energy, encouraging companies to invest in renewable energy production. This presupposes, though, that the main reason companies aren’t investing in renewable energy projects is price. And when I read in New Scientist magazine on the train home that “over 5 gigawatts of [UK] wind power are currently stalled by aviators’ objections” to possible radar interference alone, I really wonder whether price rather than the planning system really is the problem.

Nevertheless, internalising the carbon cost must be part of the solution. The problem with introducing a UK tax on carbon is that it will use up an enormous amount of political capital. To be effective there would have to be a huge shift to carbon taxes. And I can see the headlines already. “Driving is just for the rich in Cameron’s Britain”! Not going to happen, is it?

People certainly don’t like being morally preached at (as Chris Hope pointed out), but they like being taxed, and changes to how they’re taxed, even less.

The problem with a tax on carbon in general is that it sets no limit on emissions – so, since a tax simply redistributes spending power, could turn out to be ineffective.

A lot of intellectual effort seems to be going into working out what is the “right” price for carbon. The Kyoto idea of carbon trading may have had a lot of problems, but the principle of letting the market determine the carbon price (by squeezing supply) was the right one.

So what’s my contrarian position? OK (4): Right now energy policy should focus entirely on removing all obstacles to the development and roll-out of renewable forms of energy. Let’s see how far that gets us.

Guilt is not an appropriate emotion for dealing with this problem

Chris Hope was the only one last night who explicitly mentioned that the West caused the problem and should pay to fix it.

Well, I’m sure that “from each according to their abilities”, despite its connotations, might be a principle that could reasonably be applied in the context of international climate change negotiations. But what appears to be happening in the Copenhagen negotiations (I was hoping to find out more last night) is that the aid agenda has taken over the global warming agenda.

For starters, I don’t see a lot of evidence of binding emission targets being linked to these large transfers of money. But for the main course, we’ve brought some more presuppositions with us. There are serious doubts that aid is what’s needed to promote development. Yeap, for decades we’ve been following a seriously flawed policy. For example, Paul Kagame, President of Rwanda, wrote in yesterday’s Guardian, that “Africa must attract broad investment, not rely on handouts, if we are to sustain development”.

What’s needed is trade, not just aid.

Aah, you say, the Copenhagen largesse is investment. Well, maybe some of it will be spent wisely. But there is plenty of money in the world – too much in fact (that’s what caused the credit crisis) – looking for investment opportunities. Why do we need billions more?

A cynic, and I am one, so I’ll carry on, might even conclude that the $100bn or whatever comes out of the wash in Copenhagen, is in fact a further Keynesian stimulus for sluggish western economies. Think about it. Many of those pounds, dollars and euros are going to be spent on – to hazard a guess, as the details are not very clear – engineering projects that will be carried out by western companies. And I would have thought Gordon Brown (who’s driving this handout) is savvy enough to know this. Watch shares in Aggreko and Balfour Beatty when this deal is done!

And what happens when the money runs out? When we eventually decide we don’t need to pay developing countries for a climate deal, or decide that they’re not keeping their side of the bargain (whatever that is)? The money will be like aid, creating dependency.

On the other hand, and let’s call this my final contrarian position (5): paying for ecosystem services – and here’s some good news that could come out of Copenhagen – and/or energy, such as desert solar, will (if executed properly) provide countries with sustainable income streams which will support their further development.

March 5, 2009

Greening some Greenwash Debunking

Filed under: Biomass, Forests, Global warming — Tim Joslin @ 10:51 am

Oops, I was going to title this post “Greening some Greenwash”, then I realised that it’s the response to the greenwash that I object to.

I came across an interesting feature in the Indy this morning. It’s presented in a rather annoying fashion as you have to step through each page, rather than scroll down to what you want. A bit like in those PowerPoint presentations with bells, whistles and moving graphics everywhere, the technology has clearly taken over.

The feature became even more interesting when I got to point number 8: Ancient forests must be axed (sic). Red flags to bulls and all that. There’s a picture of some trees and the writer explains:

“It isn’t picturesque but it is practical. It sounds ruthless, but wheezy old trees can’t suck up the carbon like they used to. A tree absorbs roughly 1,500 tonnes of CO2 until it reaches 55 years of age, after which absorption slows. And when that tree decomposes, it belches all the CO2 back out again. So although the results won’t be terribly scenic, if we were utterly rational, our trees should get the axe after reaching their CO2-hoovering peak. The wood can then be used to make furniture, houses and many of the products we currently manufacture from less sustainable materials. We should then plant fresh seedlings to farm.”

No, no, no!

Let’s try and explain this in baby-talk.

1. There’s carbon in the atmosphere, principally in the form of a gas called carbon dioxide (CO2).

2. Trees take up CO2 from the atmosphere and incorporate the carbon in organic matter: leaves, roots, trunk, branches, twigs, bits of these things incorporated into the soil, as well as into the things which eat the above and into the things which eat them. For simplicity, let’s just say they take the carbon from CO2 and turn it into wood.

3. Now, in the case of the existence of a forest compared to its non-existence, the amount of CO2 in the atmosphere is reduced by an amount equivalent to the carbon stored in wood in the forest.

4. The amount of CO2 in the atmosphere does not depend on how quickly the trees are taking up carbon. How quickly trees are taking up carbon affects only the rate of change in the level of CO2 in the atmosphere, not its actual level.

5. Once a forest is fully grown it can hold no more carbon. Strictly, this maximum is reached when the carbon released by decay of old trees is matched by the uptake of carbon by the new trees which naturally spring up to replace them.

6. Chopping down ancient trees in order to plant new trees will not, therefore, lead to more storage of carbon. It will lead to less because the fallen old trees will start rotting and will release carbon faster than the tiny new trees can take it up.

7. The writers suggest that the wood from the ancient trees can be used to make furniture and so on. That’s true. But it will not keep carbon out of the atmosphere if old wooden furniture is thrown out and replaced by the new furniture. The old furniture will start rotting (or be burnt) as soon as it leaves the benign environment of our dining rooms.

8. Sure, we could replace some plastic in our homes with wood, but we have to understand the principle: the minimum amount of carbon in the atmosphere will occur when the maximum amount of carbon is stored in wood. This will be when everyone is using wood as a material where possible, and where all the forests are full grown, not when they’re tiny growing “fresh seedlings”.

9. Forests in general store much more wood than buildings (which may incorporate wood in furniture or otherwise) on the same land. And forests collectively take up more land than buildings. It follows that the main determinants of how much carbon is stored in the forest to wood-product system – and is therefore not in the form of CO2 in the atmosphere – are (a) the amount of carbon stored per unit area of forest and (b) the total area of forest. As I’ve explained, this will be at a maximum in mature forests.

10. So leave those ancient trees alone.

January 15, 2009


Filed under: Biomass, Energy policy, Global warming, Media, Science and the media — Tim Joslin @ 8:10 pm

I’m sure that, like me, you woke on Tuesday, turned on BBC Radio 4, and heard the sensational news broadcast between 07:43 and 07:46 on the Today programme (please podify the paper review segment, Mr BBC!).  Yes,  George Monbiot had used his Tuesday Guardian column to start a campaign against the Aga!  The crusade was even flagged on the paper’s front page.

Actually, the Aga is only mentioned in passing in George’s column, mainly to make a rhetorical point, it seems.  The article is a bit of a ramble about class and green politics, and is more about flying than heating/cooking.  Perhaps it was the Guardian’s editor who decided to emphasise the Aga point.  Nevertheless, George claimed that:

“A large Aga running on coal turns out nine tonnes of carbon dioxide per year: five and a half times the total CO2 production of the average UK home…  So where is the campaign against  Agas?”

What made George’s article stick in my mind was that I happened to notice a couple of hours later on Yahoo! Finance that Aga’s shares were one of the day’s biggest fallers at that point.  Wow!, I thought, Monbiot is verily the Heineken of eco-babblers: he reaches parts other green commentators simply cannot get near.

But then I read in Wednesday’s Guardian that Aga had – coincidentally, or is George monitoring the company’s financial calendar?, is he a share-holder?, or maybe a short-seller? – announced poor results on Tuesday morning. The Guardian’s report (the online version, which apparently appeared first, has been edited in several places to produce the Wednesday print version) – supplemented by an amusing cartoon – drew heavily on George’s piece.  Graeme Wearden wrote:

“In a column in today’s Guardian, he [Monbiot] declared the start of a campaign against the Aga. ‘A large Aga running on coal turns out nine tonnes of carbon dioxide per year: five and a half times the total CO2 production of the average UK home,’ he [Monbiot] wrote. ‘To match that, the patio heater would have to burn for nine months.’ “

The numbers didn’t stick in my head, but I was mulling over whether an Aga is really an inefficient way to heat a home.

First off, I reasoned that if the Aga runs on oil or coal (apparently these beasts can run on practically any form of energy – I’ve just put myself on the waiting list for the nuclear-powered model) then it could be more efficient than some other forms of heating.  Virtually all the heat would be captured, which would not be the case for electricity generated in coal- or oil-fuelled power stations, which would suffer from energy losses, first, because not all the fossil-fuel energy would be converted to electricity (waste heat is lost at the power station, but useful at the Aga) and, second, during electricity transmission.

On the other hand, I understand we have to move away entirely from fossil fuels.  George mentions that Agas can run on electricity as well.  Great!  This can be generated renewably.

Would Agas be less efficient than any other form of electric heating?  No, of course not, since in both cases all the electrical energy converted goes into heat – normally when considering efficiency you worry about waste heat, but this doesn’t apply when heat is what you want!  OK, heat pumps would of course be more efficient as they use energy to extract heat from the environment, but we’re comparing the heating habits of different social classes in the UK today, and hardly at the moment anyone has a heat-pump.

With any conventional form of space heating the energy required doesn’t depend on the muscle of the heating system.  What it depends on is the rate at which energy is lost from the building.  Assuming the system has some kind of thermostat, and doesn’t stay on until the occupants of the house have died of heat exhaustion and turned to dust, what is important is the insulation of the property.  We only have to worry about the heat losses.  These might, of course, be higher than otherwise if heat escapes up a chimney, if the thermostat is turned up or if a heater is left on 24/7, as Agas tend to be.  But Agas cannot possibly be in themselves any less efficient than other heaters using the same energy inputs.

Sure enough, today’s Guardian bashfully includes a correction:

“A Comment article said that a large Aga running on coal turned out nine tonnes of carbon dioxide per year: five and a half times the total CO2 production of the average UK home. It is 35% more than the total produced by the average home (This is indeed a class war, and the campaign against the Aga starts here, 13 January, page 27).”

The text of the online version of Monbiot’s column has been amended, so no longer makes sense (in this case it might have been better to asterisk the text and put the error in a footnote).

We still have what appears to be a misleading statistic.  A “large Aga running on coal” is likely to be in a big, detached house.  It’s not that surprising such a heater/cooker produces 35% more CO2 than the average home, which must include much smaller properties, some of whose occupants perhaps can’t afford to keep themselves as warm as they’d like.   

George asks why there is a campaign against patio heaters and not Agas.  The point, of course, is that patio heaters heat the outside, which is a bad idea.

Bit of a bad day at the office for Monbiot, but what bothers me most about the issue is that, according to the Guardian:

“Aga said it had seen a shift of interest away from oil-powered cookers into wood-fuelled models over the last year, a time when the oil price soared to its record high of over $147 a barrel.”

Using wood, of course, is even worse than using oil, coal or fossil-fuel electricity.  The arguments against the supposed sustainability of biofuels apply to a biomass energy source like wood.

It turns out that the UK is already importing wood for stoves.  According to the SocietyGuardian Environment article:

“Britain grows up to 1m tonnes of domestic firewood per year, according to the Forestry Commission, but we also import up to 180,000 tonnes of wood and wood products. The 25% to 30% increase in demand for logs year-on-year is proving hard to satisfy, says Vince Thurkettle, a forestry and woodland consultant.”

Nevertheless, Thurkettle is optimistic:

” ‘The dramatic upturn in demand for firewood is fantastic news in many senses because, in theory, we have so much of this resource that it is hard to see it ever running out,’ Thurkettle says.”

The numbers must stack up then, mustn’t they?

“Convinced that the new love affair with wood is a long-term phenomenon rather than a temporary dalliance, the government’s current woodfuel strategy for England aims to bring another 2m green tonnes of wood to the market by 2020 – enough to heat around 250,000 homes.  …this represents less than 50% of the potential unharvested firewood already available in privately owned English woodlands.”

Adding the 2m tonnes to the 1m we already have and that’s 375,000 homes that could be heated by wood in Agas or otherwise.

Let’s be generous and double the amount of firewood we can produce.  That would get us to 750,000 homes.  Wow! , that’s a lot.

Trouble is, there are something like 20 million, that’s 20,000,000 homes in the country.  750,000 is less than 4% of 20 million.

So we’re already shipping logs in from eastern Europe, where, unlike the UK, there are still some decent forests.  Not for long, I fear.

Maybe George could let us know what he thinks about forests here and abroad being turned into ecologically barren tree-farms on behalf of the UK middle classes…

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