There has been a great debate during the past week on the What’s Up With That blog, about a new global warming theory. I no longer believe the new theory to be valid, but taking part in the debate had the advantage that it clarified for me some of the issues.

If you consider this as a standard problem in heat transfer, at equilibrium the outgoing energy must balance the incoming energy. We know how much radiant energy the sun inputs, and we seem to agree on its fate – X reflected into space, Y adsorbed by the globe. So the question is how does Y (plus any input from geothermal and man-made energy) leave the globe? Ultimately it can only leave by radiation, because convection and conduction can play no part in space. And indeed, viewed from space we can see all the atmospheric absorbers playing their part, just as we wondered about the sun’s spectrum a century or so ago.

Interestingly, the only gases that play a role in our radiation budget are those that are active in the infrared, which are known as the greenhouse gases. Oxygen, nitrogen, argon and other monatomic and symmetrical diatomic gases in the atmosphere are to all intents and purposes totally transparent to the outgoing radiation. But the greenhouse gases play a role in both incoming and outgoing radiation. They heat the atmosphere by adsorbing ultraviolet from the incoming radiation, classically in the case of ozone, which undergoes photolysis with photons of less than 330nm to produce an oxygen molecule and an active oxygen atom. Nitrous oxide also absorbs strongly in the ultraviolet, but only photolyses with photons of 240nm and less, which is one reason why it is relatively long-lived in the atmosphere. Carbon dioxide and water do not absorb ultraviolet significantly at wavelengths in the atmosphere, so play no part in warming the atmosphere by uv absorption.

Greenhouse gases absorb relatively short wavelength infrared and re-emit slightly longer wavelength infrared from both incoming and outgoing radiation. They therefore heat the atmosphere by absorbing the incoming radiation and so reduce the energy available at the surface.

However, when the surface re-radiates, the greenhouse gases absorb the outgoing short wavelength infrared, which also heats the atmosphere. It is an interesting question whether the reduction in energy reaching the surface from incoming sunlight is greater than the energy trapped by absorption from the outgoing radiation. But key is the fact that the greenhouse gases warm the atmosphere by an estimated ~33 deg K. The more greenhouse gases there are, the greater the energy they contribute (whence the concern about global warming).

We know this from looking at the spectra. The figures below show the spectra over the Arctic – chosen because there is much less water vapour in the way, and because water vapour is such a strong absorber, it dominates the same spectrum over the tropics. In the upper curve, we are looking down at Earth, and can see that the outgoing radiation is characterized by:

1. The Arctic is basically radiating at about 268^oK

2. There is an absorption ‘bite’ at around 15 µm due to both H₂O and CO₂

3. There is a further ‘bite’ at around 9-10 µm due to CO₂

4. There is a big ‘bite’ at less than 8 µm due to H₂O

In the lower curve, looking up at night, we see:

• Most of the adsorbed 15 µm energy is re-emitted and returned to the surface.

• From about 12 to 8 µm there is no returned energy – it has all escaped to space except a little of the energy adsorbed and re-emitted by CO₂ at 9-10 µm.

• From about 8 µm most of the energy absorbed by H₂O from the outgoing radiation is returned.

Thus, when the surface radiates, the greenhouse gases absorb the outgoing short wavelength infrared, which also heats the atmosphere. Note that the only real contribution from CO₂ is that little bit between 9-10 µm.

The energy deposited in the atmosphere is distributed primarily by convection. Convection is driven by a) surface heating and cooling and b) evaporation of water (moist air is lighter than dry air). As the air rises, it cools and the point is reached where it is cold enough for the water vapour to condense, which releases latent heat. At about 12km above the surface, the pressure reaches about 10kPa and water vapour no longer plays a significant role. Instead, heating of the atmosphere takes over, and the temperature rises with altitude. Mixing is dramatically reduced, because convection is no longer possible. The region where this change occurs is called the tropopause and the region above the tropopause is the stratosphere. The tropopause is not a particular point, but a region extending from about 10km to about 18km over which the transition from troposphere to stratosphere takes place.

Nevertheless, if you integrate the energy that is finally lost to space, you discover that we radiate primarily through the 12 – 8 µm ‘window’. There is some contribution from the ‘grey window’ at greater than 16 µm, but it is relatively small (around 5% but varies with latitude)

Happy New Year!

The Festive Season is a time to relax and be refreshed. This year, much of my time was spent reading two books I had been given.

The first was the autobiography of my old friend, Kader Asmal. We first met when he was Minister of Water Affairs. When we moved to Cape Town, he was a neighbour, living just across the road. Over the years we became friends and political sparring partners. He would tease me about my ineffectual white liberalism, that had flapped its hands at the horrors of apartheid. I would tease him about the disaster called communism, and how it always corrupted its leaders.

So reading his autobiography was a delight. I had not realized his role in setting up the Truth and Reconciliation Commission, how the early films of the Nuremberg trials had coloured his life and driven him to a passion for human rights. I finally understood why he had been so interested when I shared with him my view of the greatest disaster of the 20^th century – that 160 million people had been slain by the leaders of the nations to which the dead had sworn allegiance, a United Nations statistic. We debated at some length why the 21^st century would be any different. My view was that modern communications made such crimes impossible to conceal, and could drive revolutions against oppressors, as the Arab Spring had demonstrated. Kader accused me of being the perpetual optimist.

It took the second book, The Fear – The Last Days of Robert Mugabe, by Peter Godwin, to show me that my optimism was misplaced. Godwin documents what he calls the politicide, the killing of thousands to instil the fear that keeps Mugabe in power. It is not merely Operation Gukurahundi, the slaughtering of some 20 000 Ndebele who had the temerity to support Joshua Nkomo’s ZAPU party. That happened nearly thirty years ago, ‘an unfortunate episode in history’. It is the ongoing use of the organs of the state to smash the opposition – literally.

Godwin writes of his curiosity, when visiting Zimbabwe soon after the 2008 elections which led to the sham power-sharing of the MDC in government, that he saw so many wheelbarrows with people riding in them – until he realized these were the injured, with shattered bones, discharged from the ZANU torture centres and being trundled to hospital.

Godwin reports on his visits to the hospitals. One patient’s story suffices. Questioned about his political affiliation, he admitted he had been the election director for the MDC in Harare. He was whipped; kicked in the face; stripped naked; while someone stood on his neck, beaten with branches until there was no skin on his back; and finally a truck was driven back and forth across his legs. Miraculously, he survived.

Schools were turned into torture centres; homes were torched and women and children incinerated. One woman was gang raped by seven youths, all of whom she recognized as children of her village. Godwin writes of a child trembling at the sight of a twin-cab pickup truck – it was in such a truck that the child last saw his mother, blindfolded and being tortured. In the city, the child was thrown from the truck; the mother’s charred body later discovered in the bush some 50km away. The final tortures described to Godwin are so obscene that the Marquis de Sade himself would have been appalled at their savagery.

But there are also stories of heroism in the face of such savagery. Morgan Tsvangirai was repeatedly arrested and tortured – and he is the leader of the MDC. He fled, then returned for another dose. Godwin describes the problems Tsvangirai faced on agreeing to join a multi-party government, when his party had clearly won the elections, but Mugabe refused to have the results released. One can only admire a leader who is prepared to stay in the face of the kind of threats he faces.

Another hero is Roy Bennett. Appointed a minister in the new government, he was warned that he would be seized as he appeared to be sworn in. He was duly arrested and thrown into a jail of medieval awfulness. But he is a Zimbabwean through and through – when he speaks Shona on the telephone, locals cannot tell that he is a white man. While in jail, the famous spirit medium ambuya Makopa sent him protective muti, and when he was finally released, she who normally never leaves her home was there to greet him.

But the nightmares of the torture of one human by another remain. Kader Asmal should have left an enduring legacy of absolute respect for human rights. Instead, his heirs in government support the megalomaniac to our north. The lessons of the 20^th century are passing them by.

How I coped with COP17

I was asked to represent the World Federation of Engineering Organizations at COP17. I even got a formal letter acknowledging my nomination, which would gain me admission to the holy of holies. Wow! I thought.

The reality was somewhat different. To say that the thing is barely organized chaos would be to flatter it. Yes, there is a formal COP process, and you can get caught up in a long round of meetings where such critical issues as "Can Cyprus be admitted to Annex 1 in terms of Section 19.3(a) i?" get discussed. (It was!)

But much of the juicier stuff was closed to us mere observers. There was one such meeting, an "Informal consultation on the issue of response measures" which was nominally open to observers, but when I entered the tiny, packed room, an officious, haggle-toothed witch chased me out with her broomstick. The meeting was Closed - there was a misprint in the programme.

The formal process involved perhaps 1500 of the delegates. What about the other 13 500? Well, there were official side events and unofficial side events, at all of which various groups promoted their views. One of the most valuable was an international business grouping, which reported each day on progress towards achieving a Text.

The Text is the Holy Grail, the statement made at the end of the COP. All the arm-wrestling between the Party delegates was aimed at a satisfactory Text. So the daily summary was a key event. The Press and many observers followed it faithfully. But it was hosted by business, so it took place 2km from the Conference Centre. COP is not business-friendly!

I attended quite a few of the side events. Generally, it was the converted talking to the faithful. At one, the Hadley Centre presented results showing huge increases in storm events worldwide. I enquired whether the results had appeared in the published literature, or, if not, whether the data from which the results were derived were available for independent scrutiny. My question was not answered publicly - instead, I had to approach one of the speakers to find out that the results had not been published and that the data were adapted from a publicly available data set, the adaptations to which would be made available once the paper was published. Yeah!

Another was an All-African event. There was much beating of chests over the damage being done by climate change - yet the damage was strangely familiar. So at the end I enquired whether the problem was not either lack of infrastructure or failure to maintain existing infrastructure, both of which could be fixed by engineering. It might be better to do the engineering than to hang around and wait for climate change handouts, which I personally doubted would be available any day soon. Some quarters showed much appreciation for my comments!

A really good event was hosted by the World Coal Association. Being business, it took place late in the evening and in the smallest of the side-event halls. It gave a reality that the Parties should have been hearing. The Parties were meeting to discuss ways of reducing carbon emissions. World Coal pointed out the hypocrisy of it all. During the last decade, the Parties had increased their coal consumption by more than 50%. Moreover, they were haggling about renewing the Kyoto Protocol, as if the Protocol could save the world. Yet World Coal claimed that merely decommissioning old coal-fired power stations or upgrading them to modern standards would reduce emissions by about 6%. Even if the US had signed the Protocol, and everyone had met their commitments, Kyoto would only have saved about 5% of the emissions.

The front row of this meeting was packed with the yellow tee-shirts of the Sierra Club. In discussion time, I said the dichotomy revealed by the World Coal Association deserved to be heard by a wider audience. Well done, the Sierra Club, for being present - but where were Greenpeace and Oxfam and WWF? They needed to hear this message. Yet they were burying their heads in the sands, just like the Parties, because this was a message they did not want to hear.

Afterwards I was mobbed by the Sierra Club. Could they quote me? Who was I, exactly? It transpired that the Club had held an Event on the beachfront, where they had all buried their heads in the sands in protest against the inaction of the Parties. Had I subconsciously picked up their message? Would I like to join the Club? Praise indeed!

In the end I had to decide that I could no longer be part of this farce. The world could not much longer afford to sustain so much hot air. Carbon is part of life - COPs are the way of death. I left with a huge feeling of relief, well before the hypocrisy could be reduced to a Text.

The one-handed economist

An economist has said that any new disaster could spell the end of the nuclear industry.

I am not certain why economists insist on stepping outside their comfort zone to pontificate. "Give me two handed economists - that way their chances of being wrong become very small" said one president who had suffered from their ill advice.

The Japanese disaster reminds us a) that no system can be made absolutely perfect b) that when a nuclear disaster does occur, the consequences can be considerable and c) compared to the previous disaster at Chernobyl, the actual consequences were several orders of magnitude less.

Thus we engineers are getting better and better at a) reducing the risks of an accident occurring in the first instance and b) reducing the impact of an accident if it does occur. In the light of Fukushima, nations around the world have reviewed their nuclear safety, and found that comparatively minor improvements (like moving a generator out of the way of any flood!) are all that is necessary to reduce the risks to very low levels.

Over 6% of the world's primary energy comes from nuclear energy. Last year, the new nuclear energy that came on stream was larger than the much heralded renewable energy, in terms of energy actually delivered.

6% may not sound like very much, but it is six times larger than all the renewable energy so far installed. Those forests of windmills, acres of photocells and sun-capturing mirrors don't actually yield very much power. And nuclear power is there to help out when the wind stops blowing or the sun stops shining. It isn't going to go away any time soon!

Job creation

There is a remarkable myth propagated by the green lobby, that renewable energy will create jobs. The myth has almost more believers than any other religion.

Why is this a myth? It is because the number of jobs created by any new venture is not related to the spend on construction - those are short term jobs. Yes, a few people work while the project is being built, but this is part of the social cost, the sunk capital. If the project then doesn't produce, then NO jobs are created.

This is not to say that construction work is not job-creating. As an engineer, I would never say that. But it is the productive facilities or supportive infrastructure that we create which ultimately gives new jobs, not the actual work that goes into the construction.

Instead, the number of jobs you create is related to the number of customers you create once the project is up and running. You can see this quite easily if you think of an energy project which sells no energy once it is producing. Rather, jobs are destroyed, because you have wasted potential job creating wealth on a useless project.

The same argument applies to what you might call the marginal job creation. Consider two projects, one producing the goods at cost X and the other the same goods at cost Y, where X>Y. Then there will be more customers for Y than for X, and therefore the second project will create more jobs than the first.

This applies DIRECTLY to renewable energy. It costs more than coal-fired energy (yes, even when you include external costs). If you doubt that it costs more, you have only to read the documentation underlying IRP2010. So renewable energy actually creates less jobs than coal. The myth does not deserve the lip-service it is paid.

Are you short of gas?

The State is having difficulty persuading the petroleum industry to supply sufficient LP Gas. Minister Peters would like to convert 1.5 million households to this fuel by 2016.It would make a great difference. At present, unsafe fuels cause thousands of 'shack fires' annually. tens of thousands of homes are destroyed and many lives lost.

Part of the problem is the R8.15/kg regulated price at the refinery gate. This price is too low, and the industry cannot justify expansion/ This cannot be the whole story, because the retail price in Gauteng is R21.60/kg. Where does this huge markup come from? A few years ago I studied LP Gas distribution internationally. In China, gas left the refinery at (then) $370/t and reached the streets at under $400. In Morocco, where Government has also actively encouraged LP Gas use for the poor with great success, a refinery gate price of $350/t translated into a street price of just over $400, but there was a small subsidy of about $20/t.

So there are two problems we face. The first is the ongoing desire to regulate the price of petroleum products. Government has been speaking about deregulation for years, and doing nothing. The result is that the industry has underinvested in refinery capacity, and we are having to import more and more of all fuels every year, which is inherently more expensive than producing it from imported crude oil.

The second is the distribution model for LP Gas. There is layer upon layer of handlers, each of whom takes a cut. Much of this is spuriously justified by safety concerns. The LP Gas Safety Association has done an excellent job of promoting safety, but each layer of handlers now justifies its existence (and markup) on the grounds that safety is critical. It isn't. The local safety record is no better or worse than international records.

Moreover, Government unwittingly supports the distribution model by requiring licences all along the way. You even require a licence to store a few cylinders of gas in a spaza - which you can't get because the spaza doesn't sit on an identifiable erf.

A deregulated market would see refinery gate prices rise, distribution costs fall dramatically, hundreds of jobs created in an efficient distribution chain and a consumer who was grateful to a sensible Government for getting the hell out of the way.