The Earth is a Fridge

No, I’m not a teapot. I’m serious. The way the climate system works is that, over a year, there is a net gain of heat in low latitudes and a net loss at high latitudes. Heat is transported from more tropical regions and radiated away at the poles.

Now, I’ve been mulling over the mystery of why Northern Hemisphere warming (as measured by the mean surface temperature) appears to have slowed over the past decade or so. I suggested a while back that, in view of the rapid industrialisation of China in particular, perhaps renewed global dimming has a role to play.

I recently felt some encouragement to persist from Sue Solomon’s comments in the Guardian recently that:

“…there are climate scientists round the world who are trying very hard to understand and to explain to people openly and honestly what has happened over the last decade.”

And so they should.

Realclimate was a little sniffy about the Guardian’s reporting of the science aspect, with a curious exchange at comment 47, but the (tentative) conclusion seems to be that Solomon’s findings relate to some kind of poorly understood feedback mechanism rather than a climate driver (i.e. an external effect on the climate system).

Back to the story. As I said at the start, the Earth is a giant fridge.

Now, it has suddenly occurred to me that the efficiency of the fridge could be different when the whole system is in a warmer (or cooler) state. If this effect is significant you’d therefore expect periods of more and less rapid warming as the Earth’s ability to radiate away heat changed.

Cutting to the chase, it seems to me that sea ice cover reduces the ability of the planet to radiate heat away; more to the point, loss of sea ice increases its ability to radiate heat away. Ice is a good insulator.

What’s been happening up in the Arctic is that “multiyear” ice has disappeared rapidly over recent years.

Now, if some relatively warm water ends up under some ice that’s already there, at best it can slowly cool to around -2C (when it is in equilibrium with the ice) – because of insulation the ice will not get much thicker. But if, come winter, the sea is not already covered in a layer of ice, the water can cool relatively more and can turn to ice and lose a lot more energy in doing so. Simples. [Actually, it's not: what may be critical is the amount of surface water that, as it cools, becomes more dense and sinks, allowing heat to be lost from a greater volume of water than at a lower initial surface temperature. The amount of "ventilation" of the water column (by wind) may also be an important factor in determining how much heat can be lost before the insulating ice layer is formed at the surface. Furthermore, Wikipedia notes the process of "brine rejection" whereby water just under the freezing layer becomes more dense (because ice doesn't incorporate salt) and sinks may also be important - obviously the amount of brine rejection depends on how much freezing occurs each year.].

What I’m suggesting is that the Earth’s refrigeration mechanism will be more efficient the less – in extent and thickness – sea ice there is at the start of winter. This doesn’t mean the planet will start cooling, of course, but it could slow the warming.

I thought I should do a rough calculation to see how much energy it takes to melt the Arctic sea ice each year. The interesting Stoat blog links to some data showing that very roughly 10 million km2 of ice freeze and melt each year.

I’ve seen the nature documentaries, so let’s guess that this ice is on average 1 metre thick.

To melt this ice alone takes 10^7 (the area) *10^6 (to metres cubed) *10^3 (to litres ~= kg) *334*10^3 J (latent heat of fusion of water) = ~3.34*10^21J.

I also happen to know that doubling CO2 will lead to a forcing of around 4W/m2 over the whole planet. 1W/m2 is therefore quite a significant number. How much is 1W/m2 over 1 hemisphere over a year?

The area of the Earth’s surface is ~500m km2, so 1W/m2 of the northern hemisphere is, over 1 year, 250*10^6 *10^6 (converting to m2) *365*24*3600 (a year’s worth of seconds = ~30*10^6) = ~7.5*10^21J.

So, just freezing the Arctic sea ice every year, never mind cooling the water or ice down implies that the Earth radiates away heat equivalent to a continuous forcing of around 0.4W/m2 of the entire surface of the northern hemisphere.

In fact, if we assume the water has to be cooled down as well, that 0.4W/m2 becomes a little bigger (the specific heat of water is around 4J/g/C – i.e. 4J heats 1g by 1C).

Of course, the extra heat loss in winter while the water is cooling and freezing when the ice extent is low needs to be weighed against the extra heat gain in summer by the albedo change due to the absent ice sheet. Looking at it another way, when there’s no permanent sea-ice, the albedo-feedback-assisted summer melting and winter freezing exactly cancel out. Obviously. My point, though, is that there is a circulation and the Arctic cools water that ends up flowing back south as a cold deep current (so it’s the 4J/g/C released when water cools rather than the 334J/g when it freezes that’s important). This mechanism is cut off by the insulating effect of a layer of sea ice. A corollary is therefore that improved Arctic fridge efficiency should strengthen the thermal oceanic circulation. In total, over a year, once it’s warm enough for the sea-ice to disappear in summer, more cold water should sink and flow south than before, thereby allowing more warm surface water to drift north.

There could be an optimum Arctic cooling efficiency when it’s still cold enough for the ice to freeze by the end of the winter (to reduce heat uptake during the early summer) but warm enough to mostly thaw by the end of summer.

In conclusion, I present, in the hope of encouraging progress towards an explanation of the lack of 21st century warming in the northern hemisphere, and to supplement the Renewed Global Dimming Hypothesis, the possibly even more tentative Strengthened Earth Refrigeration Mechanism Hypothesis.

I should repeat what I may term the Warming Warning, that is, that, if underlying warming is being masked, or postponed, by either of these mechanisms and/or others, we could be in for a real shock in later decades.

Interestingly, Volcanoes can Trigger El Ninos

Once again, I’m starting this post as I’m halfway through another one that may or may not see the light of day. I was trying to put together a rant following the Royal Society’s (RS’s) panel discussion on geo-engineering (available on royalsociety.tv), which I attended on Tuesday evening. The meeting followed a report issued by the RS last September.

Rather than rule out most of the possibilities, the RS boffins recommend further research. A cynic might suggest this was self-serving; I couldn’t possibly comment.

There are numerous problems with many of the geo-engineering approaches. But I wanted to be original and see if I could find evidence to support my hypothesis (noted in a previous post) that trying to cool the planet by injecting sulphur dioxide (SO2) into the stratosphere where it would produce reflective particles would block a disproportionate amount of sunlight striking the atmosphere at a shallow angle (i.e. more tangentially). More sunlight would therefore be blocked at the ends of the day, high latitudes and in winter.

In fact, the boffins noted on Tuesday that a disproportionate effect in the Arctic could be “beneficial”. This doesn’t stop them apparently relying on a computer modelling study that simply plugs in “a reduction in global mean insolation of 1.84%”.

The RS study repeatedly discusses recent volcanic events in order to assess possible effects of the geo-engineering plan.

Having looked into the matter, I can say this is bordering on a waste of time.

Drs Strangelove want to fire enough SO2 into the sky to block out around 2% (on average) of the sunlight, their sums suggesting this would counterbalance a doubling of CO2 levels.

But this interesting graph (courtesy of WIkipedia) shows what volcanoes do:

Mauno Loa observations of atmospheric transmission of sunlight

Wow! They don’t block 2% of solar radiation, rather 10 to 20% on a regular basis, and presumably even more when a real biggie goes off.

And this is enough to cause real disruption.

First off, the boffins worry about affecting the monsoon and other aspects of the hydrological cycle, citing the effects of the Pinatubo eruption in 1991. But Pinatubo caused massive short-term cooling. Monsoons rely on the land becoming warmer than the oceans, leading to rising air, drawing moist air towards the landmass. Obviously, if you reduce sunlight by 10% or so, the land will warm much slower and could remain too cold, relative to the ocean (which is kept warm by stored heat), for a healthy monsoon.

Second, I noted in a comment on a previous post that El Chichon was followed by a strong El Nino. As can be seen from the graph I gave at the time, there was a weaker one after Pinatubo. “Could they possibly fit together?”, I found myself wondering. Yesterday, via Realclimate, I came across a paper suggesting that yes, indeed they could (pdf).

The point, of course, is that El Ninos occur when warm surface water flows (unusually) east across the Pacific (see also Wikipedia). The warm water builds up in the first place because the initial flow (ultimately due to the rotation of the Earth) creates, in turn, an atmospheric warm zone to the west (around Indonesia), and a cooler region near South America. Lower pressure maintains a significant difference in the surface level between the west and the east of the ocean (maybe 60cm!). But the feedback relies on maintenance of the temperature (and hence atmospheric pressure) differential and eventually breaks down, typically in December (when the sun is not overhead at the Equator) and the whole thing collapses like a lop-sided souffle in an unevenly heated oven. Warm waters temporarily flow east with significant effects on the global climate for a year or two.

Fairly obviously, a general cooling event, such as a volcanic eruption, is likely to trigger an El Nino.

As an aside, it might be worth noting that a warming period is likely to lead to a strong El Nino, as observed in 1997-8, for example. The warming will reinforce the feedback creating the original imbalance. 1982-3 was also a strong El Nino event:

El Chichon anomaly (1983-4 temperatures compared to 1980s)

Maybe the cooling caused by the 1982 eruption of El Chichon enhanced an El Nino that was anyway ready to take place. Or maybe it was always going to be a big one.

At the risk of trying to read too much into limited evidence, it might be possible to surmise that the 1997-8 El Nino was so strong because the global warming trend leading up to it was reinforced by recovery from the Pinatubo cooling event. Similarly, to stretch the point even further, 1972-3 is listed as a strong El Nino, and followed the recovery after the Agung eruption, though that was 10 years before and not so large as El Chichon and Pinatubo (though a graph over at SkepticalScience gives a different impression). Fascinating stuff – no wonder climate scientists can’t wait for another major eruption!

Incidentally, because we mainly measure the temperature at the surface of the planet, El Ninos show as spikes in the data, because warm surface water covers cooler layers over a large area of ocean (and in turn affects temperatures on land). When a volcano triggers an El Nino, the cooling caused by the volcano is therefore partially obscured by the El Nino. An eruption when we were already in an El Nino state would consequently likely appear to have a greater effect on global temperatures than one that triggered an El Nino.

The geo-engineering plan is entirely different to the case of intermittent volcanic forcings. The plan involves a semi-permanent sunscreen to block 2% of sunlight. The problems will be entirely different. Relying on the historical record of the effects of volcanic eruptions won’t allow us to predict all the effects of the geo-engineering proposal.

Logic tells me that an SO2 sunscreen will disproportionately affect high latitudes, where sunlight is a highly valued commodity. Politically, it would of course be next to impossible to achieve broad agreement to go ahead with the geo-engineering plan. Furthermore, in a warmer world, with increased tropical desertification, we may be relying on food production in more northerly areas. Blocking sunlight might not be a bright idea.

Nevertheless, I carried on surfing for a bit for evidence that volcanic forcings could affect high latitudes more. The best I could come up with was the Russian famine of 1601-3, likely triggered by an eruption in Peru.

Parking Paralysis (and Housing Horror)

As we head towards what promises to be a fascinating General Election, the absurd first past the post system has ensured the parties are united in their zeal to pander to Middle England. And Middle England, it seems, is consumed with localist fervour.

What is localism, anyway?

The politicians would have you believe that the first stop on the road to true democracy is to “empower communities”. That is, they assert the moral right of the current residents of a given area to make a broad range of decisions without reference to the general interest.

The idea that the primary unit of a complex modern society is a “community” of people living near one another is, of course, absurd. In fact, our personal networks – including families – are, in general, becoming more and more geographically dispersed. We have little in common with most of our neighbours, other than the area where we live.

Harking back to an outmoded idea of the community masks what is really going on. What’s really happening is that the political process is becoming more and more skewed towards vested interests and against the general interest.

Take housing, for example. This morning I heard the Housing Minister, John Healey, on the Today programme, promising to clamp down on “garden-grabbing”.

Let’s put to one side the fact that John Prescott was right: we need to increase housing density. Labour has caved in on this principle as the Tories have gradually captured local government. But below a certain threshold of population density local shops are not economically viable; nor is public transport. Pretty soon everyone’s driving to Tesco’s. And the same nauseating nimbys who prevented “overdevelopment” are complaining about the loss of local shops and whinging about “Tesco towns”.

I consider it absolutely ridiculous that I’m in London Transport Zone 3, but 10 minutes walk from a pint of milk and a newspaper. If there were a few more flats nearby and perhaps fewer large private gardens, maybe there’d be enough people in walking distance to sustain a local corner-shop. If it could get planning permission.

Let’s ignore the “community” narrative and instead consider what’s really happening with the “clamp-down” on “garden-grabbing”. What John Healey is really doing is strengthening the rights of neighbours over the owners or prospective owners of property – despite the fact that the size of gardens has marginal impact on neighbouring properties, or, for that matter, their value. If they reduce the size of a garden, those bogey-men, the developers, are not simply being bloody-minded. The market is telling them that the land has less value as a garden than as building. If the opposite was the case they’d increase the size of gardens.

Obviously, the reason why “building” is more highly valued than “garden” could have something to do with the lack of available housing in many parts of the UK. But clearly our leaders don’t see this isn’t a good enough basis for a decision. The visceral feelings of neighbours are obviously far more important.

A few weeks ago Secretary of State John Denham rejected plans for a development near Ealing Broadway station. He acknowledged that the proposed “scheme would comply with some specific development plan policies relating to the regeneration of Ealing Town Centre and would bring many benefits to the area”, including 567 homes, but judged that all this value was outweighed by his subjective judgement (in response to local concerns) that “the bulk, massing and certain aspects of the design of the scheme would be inappropriate in its surroundings. It would fail to preserve or enhance the character and appearance of the Town Centre conservation area and the setting of the Haven Green conservation area, as well as harming the setting of the Grade II* listed Church of Christ the Saviour.” One person’s fears about their “visual amenity” (an irritating phrase repeated ad nauseam in planning documents) trumps another’s need for somewhere to live.

Look, Haven Green is a mess. It’s simply not that pleasant a place. It could conceivably be improved by removing the buses which stop and indeed park (for driver breaks, I gather) on the diagonal road across the Green. A recent Ealing Council document (pdf) noted that: “A major consideration, as part of both the Crossrail and Arcadia redevelopment proposals, is the provision of better interchange with local bus services.” But Arcadia is not going ahead, and, if I understand the document correctly, Crossrail has no budget to pay for a proper bus station.

The planning process is bad enough, but nowhere is localism more evident than in the battle for control of scarce road space.

Ealing Council, to my horror, is also consulting on a dreaded CPZ (controlled parking zone), which would affect me.

OK, the proliferation of CPZs can be largely explained in terms of local government bureaucrat empire-building, but there is clearly at least enough tacit public approval to allow them to get away with it. Let’s therefore consider the CPZ in my novel terms of the “local” (or “vested”) interest and the “general” interest.

Before a CPZ is implemented in a given street, everyone has an equal right to park there. After its implementation, car-owning residents generally have absolute priority. In fact, often the schemes are implemented with the shocking inefficiency that non-residents can’t even use the space when it is unoccupied! (Schemes variously allocate a few metered bays or, better, allow metered parking albeit for limited periods and at limited times in residents’ bays).

So, in approving a CPZ, residents in effect extend their property a couple of metres into the road in one fell swoop!

Do they pay a fair price for this asset, though?

Of course they don’t.

Permits for residents’ parking on public roads are often less than £100 per year, and rarely more than a few £100s. The market value of such parking – determined by the rates in the few metered bays typically provided or in nearby car-parks – is usually at least several pounds a day – £1000s, not £100s a year.

It’s not just outsiders who, in effect, subsidise permit-holders. Residents who don’t run cars are massively inconvenienced, as is everyone when they have visitors, or use local services. Estate agents, for example, have problems parking when they quite legitimately want to show properties to prospective purchasers or tenants.

What CPZ schemes fail to take account of is that residents’ cars are part of the problem, and not the only injured party. Personally, it seems to me that there would be more social utility in reserving parking places for estate agents than for residents who just want to leave half a tonne of steel and moulded plastic outside their house for 6 1/2 days a week.

If we’re going to have CPZ schemes, then, let’s charge a market rate for the parking space – upwards of £1000 a year (and allow the option of paying a daily rate for those residents who park their car elsewhere most of the time). Then we’d reduce car ownership, spaces could be allocated to car clubs and for visitors and our parking problems would be much reduced.

What Ealing really wants, though, is not an ever-growing CPZ area. What’s happened is they’ve tried to solve the problem of commuters parking near Ealing Broadway and West Ealing stations. Entirely predictably, the small CPZs implemented have just moved the problem. Now they’re consulting on more CPZs. Nice work, if you’re in the CPZ implementation business.

Is there another policy that might make more sense than the inefficiency of selling the public parking space asset at a discounted rate to residents who think they own “their” road? It is entirely legitimate to discourage car rather than bus or shoe-leather use by commuters. Why not, therefore, consider a congestion-charge scheme for non-residents coming into the centre of Ealing? One might hope that some of the London congestion-charge infrastructure could be fairly cheaply deployed just in the centre of Ealing. I’d suggest vehicles entering and leaving are monitored and the software programmed to charge only for those non-residents who stay in the area more than, say, an hour, since the objective in this case is not to penalise through-traffic but relieve pressure on on-street parking.

Perhaps it will take PR to slow the tide of localism. Certainly though, until the political process weighs the general interest more carefully against vested interests, our society will continue to be held back by dysfunctional and misguided decisions.

Musings of the Hemispheres

I should really try to finish one blog post before I start another on a similar topic. My last (published) post noted that the North Atlantic Oscillation (NAO), an atmospheric phenomenon, is not a climate driver, rather it’s a measure of the state of the climate – incidentally, I’m pleased to discover this morning that Philip Eden at Weatheronline.co.uk holds similar views. In a post that may or may not ever appear, I was going to note similar thoughts about the so-called Atlantic Meridional Oscillation or AMO.

It’s not my understanding of the oceanic circulation that great surges of current drive the climate. Rather the oceanic circulation is itself driven by changes in heat distribution at the surface. OK, there may be timelags and of course there’s the El Nino, but that’s about it. If the El Nino is driven by ocean currents (which I believe it is), these are, crucially, east-west, not north-south. The planet loses heat partly because heat moves (in water and air) from the tropics towards the poles where it is more easily radiated away (or used to melt ice). I suggest, therefore, that changes in oceanic circulation are primarily caused by changes in the absorption of heat at the surface. For example, if the planet is warming, you’d expect a general strengthening of oceanic circulation.

What’s piqued my renewed interest in this topic is James Hansen’s release of temperature data for 2009, available over at Realclimate. In particular, Hansen includes separate temperature graphs for the southern and northern hemispheres. I reproduce these here for convenience (the diagrams in my previous post were from Wikipedia, btw):

Fig 1: Annual temperatures

Fig 2: Running mean temperatures

Looking at the right hand graphs, comparing temperature changes in the hemispheres, we see that sometimes the northern hemisphere warms quicker than the southern hemisphere, whereas at other times the reverse is true. What would we expect, though? Well, there’s a lot more water in the southern hemisphere and a lot less land. We’d therefore expect the south to warm (and cool) slower than than the north (and, in the long-term, catch up when temperatures stabilise at a different level). And, indeed, this is what appears to happen most of the time: since the mid 1970s, the northern hemisphere has warmed much faster than the south; on the other hand, the cooling (clearest in Fig 1) caused by the Mt Pinatubo eruption in 1991 was most evident in the northern hemisphere.

But – there’s always a “but” – for significant periods of time (I consider the weather can affect annual data, but not decadal trends) – for example, from around 1950 to the mid 1970s – the southern hemisphere has actually warmed when the northern hemisphere has cooled. This requires explanation.

There are only two possibilities: either the one I’ve already dismissed, that large amounts of heat are, by some unexplained causal mechanism, transferred between the hemispheres, or, that there are factors causing the hemispheres to gain different amounts of heat at different times. Specifically, for several decades from around 1950, the southern hemisphere must have either gained heat, whilst the northern hemisphere lost it, or, more probably, two countervailing factors were involved: one causing a general warming and the other cooling, but disproportionately of the northern hemisphere.

We know that increased levels of greenhouse gases are tending to warm the planet. The inescapable conclusion is that another factor tends to cool the northern hemisphere more than the southern hemisphere. The argument that from the 1940s through to the 1970s this was “global dimming“, caused by sulphur dioxide and other pollution is highly persuasive. Most of this pollution is emitted in the northern hemisphere and doesn’t stay in the atmosphere long enough to spread evenly.

What’s happening now, though?

Well, what strikes me in Hansen’s graphs is the levelling off of warming over the last few years. There’s not yet really enough data to reach any sort of conclusion, but Hansen notes 2009 was the second warmest year on record. In fact, though, his data (Fig 1), suggest it was the warmest year in the southern hemisphere and around the 7th warmest in the north.

Given the rapid industrial development of China and India, it seems justifiable to hold a working hypothesis that we face renewed global dimming.

You would expect a layer (or layers) of reflective particles in the atmosphere to reflect a greater proportion of light from the sun in the winter than in the summer, so another way to test the hypothesis would be to examine seasonal rates of warming over the past century or so. The trouble is, seasonal temperatures are very much affected by poleward heat transport and weather patterns themselves dependent on whether the planet (or hemisphere) is warming or cooling, but nevertheless I’d expect average temperatures in continental interiors (with stable seasonal weather patterns and especially anticyclonic conditions in both winter and summer) at high latitudes to fall more in winter than in summer during periods when global dimming increases, i.e. when the rate of warming of the planet as a whole slows down.

Of course, we could also put a bit more effort into simply measuring the strength of sunlight at the top of the atmosphere (to account for variations in solar output) and at ground level in cloudless conditions (or controlling for cloud cover).

If the analysis that the climate is being affected by renewed global dimming is correct, it’s really bad news. What it implies is that, when the presently industrialising nations reduce their sulphur emissions (and assuming other countries don’t repeat the exercise), we could be in for another period of rapid warming (several tenths of a degree C per decade on average in the northern hemisphere), similar to that over the last quarter of the 20th century.

Snow Madness and the North-West European Anti-Monsoon

In India, apparently, legions of weather-forecasters, from eccentrics to supercomputer-operating state-funded agencies, are devoted to attempting to forecast the characteristics of the annual monsoon.

A collective snow madness grips the UK during cold winters. Legions of weather-forecasters, from eccentrics to supercomputer-operating state-funded agencies attempt to explain events, nowadays with particular reference to global warming.

Now that the snow here is melting and low grey cloud has parked on top of London, the weather is simply downright miserable here.

So it seems a good day to stay indoors and join in the speculative fun.

Monsoon conditions occur when the land heats faster than the ocean during the summer, causing air masses to rise. The rising air – or low pressure – relative to the ocean, draws moist air inland, creating rainfall.

Given the cultural significance of cold winters in the UK – I have a deep desire to roast an ox on the Thames, and fond memories of 1684 are starting to fade – I suggest we should characterise the weather-pattern that brings cold weather to north-west Europe as an anti-monsoon (or perhaps “antisoon”).

The point is that in late December or early January there is often a plunge of cold air towards Western Europe. In many years this fails to reach the UK, but occasionally it does. The breakdown in the normal westerly airflow is caused by the reverse of monsoon conditions. Rapidly cooling air over land (high pressure) tends to flow out over the warmer ocean (low pressure).

I’ve noticed the meteorological profession making bold – in my view even reckless – predictions about future British winters. Rob (or “Reg” as he was introduced by a BBC anchorman!) Varley insists that our cold winters will be less cold in the future. We’re even told that future generations won’t know what snow is!

Actually this is what I thought until recently. Whenever it snows I rush out with my camera, thinking I might never see the white stuff again.

But now I’ve thought about the matter a little more deeply. In fact, I’m ready to spout some speculative scientific ideas.

I now doubt we’ll never see snow again, for the simple reason that the temperature difference between average and cold UK winter weather (the “anomaly”, perhaps) is of the order of 5-10C. Global average temperatures have risen by an order of magnitude less.

Winter weather in Britain depends not on the global average temperature or even the temperature of the North Atlantic. Rather, it simply depends on which direction the wind is blowing in. And it so happens that high pressure over Scandinavia and/or Greenland causes easterly winds over the UK.

When in the future can we expect such high pressure systems to develop? Will they become less frequent? Or perhaps the real question is why they have been rare over the past 30 years or so, leading to a succession of mild winters in the UK?

The meteorologists have an alarming tendency to attribute causal significance to what are in fact the phenomena in need of explanation. The jet stream is a case in point.

During cold UK winters the jet stream moves further south – over Gibraltar, perhaps, rather than the Channel. Depressions therefore track south of rather than across the British Isles.

But the jet stream must be caused by something. In fact, it can only result from pressure differentials in the atmosphere – rising air (to its north) and falling air (to its south) if you like.

This brings us to another meteorological concept: the North Atlantic Oscillation (or NAO). This isn’t really an oscillation at all, rather a measure of the pressure difference between the Azores (usually “high”) and Iceland (“low”). The NAO measure fluctuates rather than oscillates (unlike the El Nino Southern Oscillation, ENSO, which is driven by movements of water). But the NAO concept does bring us a little closer to an explanation of the root causes of UK winter weather. Here’s a graph of the NAO over the last century or so:

Winter NAO Index

I’d say there appears to be some correlation between the NAO and cold and mild winters. 1947, 1963 and 1979 were all years of low (negative) NAO, whereas the recent run of mild winters occurred while the NAO was high.

But what determines the NAO?

Here’s my hypothesis. We need to look at not how warm the planet is, but at whether or not it is warming.

The point is that there is a lag between atmospheric warming and warming of the ocean (we’re concerned here with the ocean surface, not the deep ocean, where the warming lag is centuries rather than just years). When the planet is warming, therefore, the land (affected directly by the atmospheric temperature) will be warmer relative to the ocean than is usual. The reverse will be the case when the planet is cooling.

When the planet is cooling, therefore, the North-West European Anti-Monsoon will tend to be stronger, bringing the possibility of cold winters to the UK.

Here’s another graph:

Average Global Temperatures

Compare this graph of temperatures with the NAO graph above. Someone can so some maths (differentiate the temperature graph!), but I’d say the NAO correlates with the rate of change of temperature. When the planet is warming rapidly, the NAO tends to be positive; when the underlying warming trend slows or reverses, the NAO tends to be negative.

And when the NAO is negative we get those proper UK winters that somehow satisfy the soul.

This set me thinking a little more.

A sudden cooling trend can result from volcanic eruptions. The cold decade of the 1810s is explained this way. Remember, the average global temperature declined by “only” 0.5C below normal back then, but the UK experienced White Christmases more often than not!

The current levelling off in warming cannot be explained by volcanic activity. Neither can 1963, for instance, although the eruption of Mt Agung occurred during the cold snap!

But the evident cooling in the 1960s can be explained by “global dimming“, resulting from particulates emitted by fossil-fuel burning.

Could the same thing be happening now? We keep hearing how many coal-fired power-stations are being opened in China. They must be having some effect, surely?

It might be worth pointing out that reflection of sunlight by particulates in the atmosphere would be expected to be more significant in winter than in summer, because the angle of incidence of sunlight would mean it having to pass through more air to reach the surface (and random scattering would be more likely to deflect the light out of the atmosphere altogether).

Or maybe the sceptic-fuelling hesitation in the rise in average temperatures over the noughties is just unexplainable “natural variation”, as climatologists suggest.

The warmest year on record, 1998, was the start of an el Nino, when warm water spreads across the surface of the Pacific. In 2010 we are seeing the start of another el Nino. I can believe the start of an el Nino would disrupt normal weather patterns and help cause a cold UK winter (cooling and a negative NAO is a necessary, but not a significant causal factor). Here’s my wager, though: next year (2010-11) will not be a cold winter. The el Nino warmth will by then have had time to spread through the entire atmosphere. We’ll have a positive NAO and a weak antisoon. I should say, in case anyone really does want to put money on the prediction, that a perusal of the historic record does suggest that while cold winters can, and often do, occur in an el Nino year, they don’t tend to occur the year afterwards.

We might be able to blame China for this cold winter, but a longer-term problem with warming the planet may be that at some point we have to stop. And maybe even let it cool down, bringing on some strong antisoons. With a bit of luck, though, it won’t be so warm by then that we won’t be able to put that ox on a spit in front of Parliament!

—–
PS I do realise that embanking the Thames during the 19th century and the demolition of the old London Bridge (which obstructed the flow of the river) make it less likely it will freeze over. I still dream of the day, though!

Playing the Energy Game

I mentioned last week that I was planning to play the Energy Game based on David MacKay’s book Sustainable Energy Without the Hot Air (SEWTHA) at the Science Museum’s Dana Centre. Well, I’ve been true to my word, although I arrived there slightly breathless after taking the Victorian tunnels from South Kensington tube station. It turns out the Dana Centre is at the other side of the museum, nearer Gloucester Road station.

Anyway, the “game” was worthwhile. It involved adjusting the UK’s energy supply and demand by using two columns of magnetic blocks to represent (decarbonised) energy supply (different flavours of wind and solar power and so on) and demand alleviation measures. We were formed into (moderated) groups to carry out this exercise and then presented our solutions in a final plenary session. All very MBA.

The attendees were all sensible and well-informed. I was therefore quite surprised by some of the outcomes. I also felt the game constrained thinking a little too much. To improve it significantly would require a software implementation and I wonder if the organisers will consider creating one.

The attendees as a whole seemed very accepting of biofuels (not our group, though, but it took quite some discussion) even though the small contribution to our energy supply suggested took up 20% of the UK’s land! There was also a general distrust of carbon capture and sequestration (CCS) and of nuclear power. Partly this was because the constraints of the game allowed only a very small proportion of the UK’s energy to be obtained from these sources, which are not entirely renewable. I felt that the idea that we could only use a small amount of nuclear power because existing known reserves had to be divided equally around the world to be particularly suspect.

Tony Robinson suggested last night that Neanderthal man died out during a previous episode of climate change (a Heinrich cooling event during the last ice age) because he failed to trade, unlike our own ancestors. If we are to solve the energy problem, then it seems to me trade must be at the heart of the solution. For me, the Energy Game as it is now builds in too much UK self-sufficiency (though is inconsistent in addressing the issue, since it does allow desert-based concentrated solar power (CSP) to be a large part of the solution). The UK is an arbitrary market in the modern world, for starters: why not English or European self-sufficiency?

Incidentally, if we are not prepared to build the Supergrid, then those countries poorly endowed with renewable energy relative to their consumption will be obliged to bid up the cost of the world’s uranium supplies and go nuclear. They will end up with more than their “fair share” because other countries will be better off using solar, wind etc. Whether the UK is one of these countries should be for the game to discover.

The game did allow energy price to be taken into consideration. This didn’t stop most groups spending a fortune on rooftop (or other) PV in the UK.

There are several aspects of the Energy Game that could be better captured in a computerised version:

1. An easier and more accurate cost analysis. Costs of demand management actions (e.g. improved insulation of buildings) also need to be included (it wasn’t on Thursday).

2. Warnings, consequences and implicit assumptions. For example, above a certain proportion of wind energy it’s necessary to either store the energy (with some losses) or trade it (also involving costs, e.g. for transmission lines). The game could produce a report detailing technical and political assumptions. In particular, it might highlight the importance of political action to create as wide and as depoliticised an energy market as possible (Europe, North Africa and the Middle East, perhaps). The game should also highlight problems such as how flying is to be powered (our team had no liquid fuel in the mix!), and note the food-supply implications of the use of biofuels.

3. A better appreciation of the time element, which was totally absent on Thursday. Instead of simply adding energy blocks, the team could specify ramp-up and ramp-down rates (and curve shapes – straight line or S shaped) for energy technologies and demand management measures. Costs could also be allowed to evolve over time, e.g. PV in particular might gradually become cheaper, in the same way as other technologies have done in the past. The game could then show you the energy mix at certain dates (e.g. 2020, 2050 – it might have built-in retirement dates for existing power-generation facilities) and give a traffic-light report on whether specific targets have been met (e.g. 20% renewables by 2020, 20% emission reduction by 2020, 80/95% emission reductions by 2050 etc.).

In short, I think you could go to town on this game in a computer programme based on the magnetic version. Your moderators would need a kit consisting of laptops and projectors (and venues would need screens or white walls!), but these are readily available these days.

Nevertheless, the Energy Game is already a worthwhile exercise.

Hansen vs. Krugman: Second (Third and Fourth Order Effect)s Out!

Yesterday’s NYT includes a right royal spat. Well, online it does, at least. In a piece titled Cap and Fade, James Hansen argues that carbon taxes would be more effective than cap and trade. Paul Krugman responds under the heading Unhelpful Hansen, by first telling Hansen to stay off his turf. Climate scientists shouldn’t dabble in economics, apparently. Tosh. Ideas have to stand on their own merits.

Having highlighted the intellectual ring-fencing which is at the root of many of the world’s problems, Krugman proceeds to un-blot his copy-book. He points out very convincingly that, from an individual consumer’s point of view, it matters not a jot whether gasoline is more expensive because of a tax or because of a cap and trade mechanism.

Krugman is right as far as it goes. But both Hansen and Krugman fail to mention the second, third and fourth order effects of pricing carbon emissions. And it is the second, third and fourth order effects that will determine the effectiveness of policy.

Let’s start at the end, because it’s more fun. The fourth order effect of pricing carbon will simply be a redistribution of spending power in the economy. I’m sure I’ve said it before, but I’ll say it again: money is just a means of distributing resources. The economic system will adjust so that the available resources are used.

Perhaps I should try to explain a little further. Money circulates. There is not a fixed quantity. Let’s imagine we put an astronomical tax on carbon. The money raised by that tax must be spent. Let’s say we decide to spend it on more doctors. Suddenly there will be more doctors to fly off to junkets round the world. Or maybe they’ll spend their money on art (or more expensive houses, or televised sport…). In which case the previous owners of the art (or houses, or sportsmen, their agents and other freeloaders) will be able to afford to fly more…

But before we even get to this unhappy state, we should consider, first, a second order effect of pricing carbon. Pricing carbon will tend to reduce the price of fossil-fuels. All that might happen is that the price of petrol at the pump remains the same, but less of the motorist’s money ends up going to the oil-producer and more goes to the government. Maybe a good thing in itself, but we’re trying to stop global warming here, not change the shares of unearned spoils divided with the Saudis. Sure, depressing the global oil price might have the desirable third order effect of reducing investment in the most expensive fossil-fuels for a while (until the lack of supply pushes prices up again), but we need to reduce consumption of fossil-fuels that cost virtually nothing: coal, in particular.

And unfortunately the second order effect of carbon pricing on the oil price is dwarfed by the third order effects of another second order effect. The second order effect (I’m trying to be rigorous, here!) is that taxes raise money. So does carbon trading. We need to consider the effects of how that money is spent.

Hansen argues that the money should be distributed to the population. This will, at least in the short-term, increase equality. And, unfortunately, when you’re trying to reduce consumption of mass-market products, equality is not your friend. Money will be taken from those whose consumption is not constrained by their financial situation and given to those who would like to spend more. Likely on heating, driving, flying and so on. Oh dear!

But there are problems with carbon trading, too. The precise outcome will depend on how carbon permits are distributed. If they’re given away to power companies, then any excess permits will accrue to these companies’ shareholders in the first instance. (Over time, these profits will encourage new market entrants, although this may not happen if only incumbents are able to access the permits). If permits are auctioned, though, then we reach a situation similar to the carbon tax. The outcome depends on what the government does with the revenue. Simply distributing it to the population would fall foul of the same equality problem as for the tax. Direct or indirect subsidies for renewable energy production would clearly be by far the best policy choice, in the hope that, once renewable energy has a huge cost advantage over fossil-fuels, everyone will switch to clean energy. Maybe.

In perverse support for Krugman’s argument that taxes and cap and trade are equivalent, government could spend tax revenues in the same way as those from auctioning permits. Very similar to Hansen’s position is the idea of tradeable personal carbon allowances. These would have the effect of transferring wealth from the rich to the poor. And remember, equality is not our friend…

Let’s make some tentative conclusions and observations:
1. The indirect ramifications of carbon pricing policies are more important than their immediate effects.
2. Carbon trading is philosophically preferable to carbon taxes, because it at least imposes a limit on total consumption. The problems arise from leakage (the concept is explained in a previous post). Unfortunately, these are very big problems – probably deserving a post of their own.
3. If there is a limit on the carbon price in a carbon trading system, then it becomes almost equivalent to a tax. However carbon is priced, governments must be prepared to push the price up indefinitely. Otherwise, I suggest, the economy will simply adjust to the price.
4. Carbon trading is a superior policy if you’re really serious about reducing fossil-fuel emissions, because government doesn’t have to set a tax at an eye-watering level. It can simply say: “this is all the fossil-fuel we can afford to burn, it’s supply and demand in the market-place which has pushed the price up.”

Unfortunately, I don’t see too many governments around the world that are about to bite the bullet and set an effective carbon price.

Lloyds Rights Issue: the Story So Far

So good: Lloyds has clearly pitched its rights price – 37p – sufficiently low for the rights issue to succeed. The rights have significant value (around 17p just now) that someone will buy them. Even if shareholders do nothing, the rights (or the shares they represent) will be sold in the market at the end of the process.

Nevertheless, I’d argue that the rights issue itself has had a significant effect on Lloyds’ share price.

I wrote a couple of weeks ago that the theoretical ex-rights price (TERP) can only be calculated based on the closing price before the shares go ex-rights. It is only at this point that the rights issue becomes close to a mathematical exercise. Nevertheless, news-flow will continue to affect the share price.

Lloyds in fact closed at 88.83p on 26th November, compared to the 91.47p closing price on the 23rd that Lloyds used for calculating the discount of the rights issue price to the share price.

Following the same method used previously (but ignoring the non-voting share complication):
(total value of Lloyds after rights issue)/(no. of shares after rights issue) = £((0.8883 * 27,161,682,366) + 13,506,882,774)/(27,161,682,366 + 36,505,088,579)) = £(37634605219/63666770945) = ~59.11p.

The rights price (37p) is therefore at a discount of (59.11 – 37)/59.11 = ~37.4% and nil-paid rights should trade at 22.11p.

The question I’m interested in is how much the rights issue has depressed the Lloyds share price.

It’s worth noting first that the rights price and the share price move in lockstep:

Lloyds rights price 30/11 to 4/12

Lloyds share price 30/11 to 4/12

The only thing that is keeping these prices so closely in step is the behaviour of market participants. Profit-making opportunities arise if the prices of the shares and the rights move out of alignment. It’s a simple “wisdom of crowds” effect.

The above graphs also show that the rights and shares have both traded consistently below the prices implied by the TERP.

The problem is that it is very difficult to separate the effect of the rights issue from the effect of news-flow. And we’ve had a lot of news: the Dubai saga, Bank of America repaying government funds and no end of speculation about the UK’s upcoming pre-budget report (PBR) which could all affect the Lloyds share price. On the other hand, the UK Supreme Court ruling that customers (aka the Office of Fair Trading) could not retrospectively challenge fees and news of the emergency loan to HBoS unbelievably kept secret during Lloyds’ takeover should have been in the share price, as these stories broke during the week leading up to the rights issue.

Nevertheless, only briefly on the first morning of the rights issue did the shares and rights trade above the TERP:

Lloyds share price 27/11

To determine whether the increased supply of Lloyds shares or news-flow because of the rights issue has affected the price, we could try comparing Lloyds price with that of other UK banks:

Lloyds share price vs RBoS' 27/11 to 4/12

Lloyds share price vs Barclays' 27/11 to 4/12

Lloyds, RBoS and Barclays are quite different businesses, but maybe we can tentatively conclude that the rights issue has caused Lloyds share price to fall relative to its peers.

But it could be worse than this. Some shareholders may have sold shares in other banks in order to take part in the Lloyds rights issue. They may be rebalancing their portfolios, whilst keeping the proportion of UK banks the same (i.e. selling some holdings in other banks to raise funds to participate in the rights issue at least for some of their entitlement, thereby keeping their holdings in the same proportions as previously to the total market values of the banks), or they may consider that Lloyds’ share price would be depressed by the rights issue.

More than that, some shareholders may have sold Lloyds shares in advance of the rights issue in order to participate. They may have tried to pre-empt the drop in Lloyds’ share price close to the rights issue.

A final comparison that may therefore be useful is Lloyds’ share price against the FTSE-100 index over the last 3 months:

Lloyds vs FTSE last 3 months

You could choose to attribute the >10% fall in Lloyds’ share price against the FTSE to the upcoming rights issue.

The problem we face is that it is impossible to be sure why people have sold shares. Financial columnists rationalise share price movements, but this is just opinion. The price may have fallen on a particular day because of fears over Dubai, for example, but it may have fallen because more shareholders wanted the money than the shares. Or both.

All we know is that there was an equilibrium between buyers and sellers of Lloyds’ shares (and rights) at a share price of 88.83p last Thursday (equivalent to 59.11p) and 54.28p right now.

It’s a question of judgement whether 59.11p, 54.28p or some other figure truly represents the long-run value of Lloyds’ shares.

Personally, I’d certainly argue that Lloyds’ share price is depressed by the rights issue. It follows that if I don’t participate in the rights issue, I have to accept that depressed share price for my rights. That’s why it seems to me that the best thing to do is to subscribe to the rights issue, even if I intend to sell the shares in a few months time.

Note that if you do nothing, the rights will be sold for you in the market and you will receive the funds raised.

Why Expedient Offers of Energy Efficiency Improvements must be Rejected at Copenhagen

Earlier this year New Scientist foolishly tried to grab readers’ attention with a cover proclaiming that “Darwin was wrong”.  He wasn’t, of course, and a right old furore was the inevitable result.  It seems misleading headlines are an inevitable symptom of the editing process employed by magazines and newspapers.  The journalist – perhaps keen to be accurate – relinquishes control to editors with entirely different priorities. A large part of their job is to tempt us to buy their product, and, once we have, to read articles they may not have had time to properly digest.

An article in this Thursday’s Guardian (p.11) caught my eye with: “India: Last of ‘big four polluters’ sets target of curbing CO2 emissions by a quarter”.  As I’m paying a lot of attention to the climate change negotiations, I realised that this seemed very unlikely, so read further (the online version linked to has a more sober title).  Many readers will no doubt have been misled by the headline.

It turns out, of course, that India is not offering to reduce carbon emissions at all:

“…[India] could curb the carbon emitted relative to the growth of its economy – its carbon intensity – by 24% by 2020.  … emissions would continue to rise… , but by less than currently predicted.”

This is similar to the action China is proposing.

The Copenhagen offerings to global public opinion from both China and India are entirely inadequate.

First, it’s not yet clear how binding the commitments are.

Second, the targets may not be difficult to meet. For example, I noted recently that:

“China uses four times as much energy as the U.S. per dollar of economic output, and more than 11 times that used in Japan.”

But simple gains in efficiency may even be counter-productive, as I’ve discussed before. In particular, Jevons’ Paradox, or the Rebound Effect, notes that as we improve the efficiency of a technology, the internal-combustion engine, for example, we tend to consume more of it, because we are increasing the value – measured in this case, perhaps, as the distance travelled – that we can obtain for one unit of resource (petrol, aka gasoline, say). Increased driving would, in this example, offset any efficiency gains, and, over time, could even exceed them!

The Rebound Effect considers demand for a technology. But the efficiency problem is worse than that. There is also a supply-side aspect. The more efficient a technology – the internal-combustion engine, for example – becomes, the greater the hurdle to replacing it, with electric engines, perhaps.

Martin Wolf, writing in the FT this week, refers to a paper from the Bruegel think-tank, which discusses the issue in depth. Wolf finds the paper’s argument that “merely raising prices on carbon emissions would reinforce the position of established technologies” to be “persuasive”. The paper, which is well worth a read, suggests that, as well as setting a carbon price at “an appropriately innovation-inducing level”, the “EU should stimulate new technologies more vigorously” by “subsidising the diffusion of existing technologies” and increasing its funding of green R&D.

It seems to me that the basic green technologies we are going to need already exist. They require “D” rather than “R&D”. And, as every entrepreneur knows, the best way to fund product development is through the income from sales. I’m somewhat sceptical that a few billion euros of government support will allow new technologies to overcome the refinements made possible by – depending on the technology in question – 10s or 100s of billions or even trillions of euros of historic sales of fossil-fuel based products.

Worse, why won’t we use both fossil-fuels and renewables? Dirty industries might simply become more and more efficient alongside green industries reliant on subsidies. We might simply consume all the fossil-fuel based and renewable energy that we can produce.

The only way to wean ourselves off fossil-fuels is to target their overall consumption, maybe by breaking the problem down into national allowances.

Until China and India are prepared to accept national limits on their emissions they will not be contributing to the task of avoiding dangerous climate change. Carbon-intensity targets are no substitute for emission cuts.

Problems with Wood Chips: Why Copenhagen’s Piecemeal Approach to Preserving Forests will Fail

We all share the same atmosphere. Wood is an internationally traded commodity. How is it, then, that, simultaneously, governments in East Asia are urging their citizens to reduce their consumption of wooden chopsticks whilst wood-burning boilers are being promoted in the UK?

Such a lack of consistency is typical of attempts to preserve forests, including the proposals apparently being discussed in the lead-up to the Copenhagen climate-change talks.

I’m finding literature supplied by the NGOs to be a lot more useful in understanding the Copenhagen discussions than anything I’ve seen in the mainstream media. A WWF “Pocket Guide” to “The New Copenhagen Climate Deal” was included with the Guardian early this week. I immediately turned to the section on forests (not apparently available online, but with some overlap to this page on WWF’s site). I highlighted the following passage about REDD which, according to WWF stands for “reducing emissions from deforestation in developing countries”:

“There is no point paying to protect one forest, if the loggers and farmers simply go somewhere else and tear that down (in the jargon, this is called ‘leakage’) – or come back in a couple of years after REDD has paid out (the challenge of ‘permanence’).”

Very succinctly put.

Why, oh why, then would we even contemplate a REDD framework that does not meet the conditions of avoiding leakage and ensuring permanence?

As far as I can tell, Copenhagen is likely to spawn a variety of different schemes for preserving forests. These seem to fall into 3 main categories:

1. Carbon-trading REDD schemes

Specific areas of land are ring-fenced from deforestation (and/or reforested or afforested) and the amount of carbon “saved” compared to “business as usual” (i.e. if the land had not been protected). This carbon is then amortised over a number of years and traded as carbon credits for each of those years.

I don’t think I’m pre-empting a lot of discussion by suggesting that such schemes meet neither of the two criteria of avoiding leakage and ensuring permanence.

2. Preservation of specific forest areas

Despite New Scientist’s flippant headline, a scheme in Ecuador to preserve part of the Amazon rainforest (which happens to sit on a lot of oil) makes considerable sense:

“Ecuador said it would abandon plans for drilling in Yasuni National Park, one of the few pristine regions of Amazon rainforest remaining, if it was paid half of the $7 billion that it expected to earn from tapping the oilfield.”

The critical point is at the end of New Scientist’s report:

“…the UN Development Programme is expected to announce plans to hold contributions in a trust fund, passing along only the fund’s interest to Ecuador. … this will give future Ecuadoran governments an incentive not to start drilling for oil, while also encouraging other nations to pay up.”

This model could at least meet the challenge of permanence.

3. National commitments to reduce deforestation rates

The Copenhagen talks are unfortunately turning into a battle between the “developed” North and the “developing” South. This artificial distinction has spawned a counter-productive “them and us” mentality. It makes it even more difficult to define, let alone agree, sensible solutions to the problem of global warming.

Likely we are past the point where reducing deforestation rates is enough. Ultimately, we will probably need to significantly increase the forested area of the planet to absorb carbon that’s already in the atmosphere. But let’s put that issue to one side for now.

The problem with the “North” buying reductions in the rate of deforestation from countries in the “South” is the leakage criterion.

WWF has defined REDD as “reducing emissions from deforestation in developing countries”. This makes absolutely no sense. We need to preserve temperate and boreal forests as well as tropical forests. You can’t assume a lot when it comes to the increasingly baroque Copenhagen negotiations, but I’d wager that none of Russia, Canada and the Scandinavian and Central European countries, not to mention Australia, Japan and New Zealand are classified as “developing”. It seems to me that the best that could happen under schemes aimed at reducing some national deforestation rates is that timber exports from those countries decrease, whilst they increase from countries not included in the scheme.

What is actually needed is a global Forest Endowment Fund which provides an income stream in perpetuity to any and all custodians of the world’s forests (and other ecosystems, in particular wetlands) in approximate proportion to the carbon stored in their trees and soils, as long as the forest remains in a defined state. Only this way is it possible to meet the key criteria, correctly identified by WWF, of avoiding leakage and ensuring permanence.