I'm a big fan of the potential of biochar to help solve some of our problems (at least when we try to follow the terra preta example), so I was disappointed to see that George Monbiot is slamming the idea - Monbiot blasts biochar (via Energy Bulletin.

The latest miracle mass fuel cure, biochar, does not stand up; yet many who should know better have been suckered into it ...

Whenever you hear the word miracle, you know there's trouble just around the corner. But no matter many times they lead to disappointment or disaster, the newspapers never tire of promoting miracle cures, miracle crops, miracle fuels and miracle financial instruments. We have a limitless ability to disregard the laws of economics, biology and thermodynamics when we encounter a simple solution to complex problems. So welcome, ladies and gentlemen, to the new miracle. It's a low-carbon regime for the planet that makes the Atkins diet look healthy: woodchips with everything.

Biomass is suddenly the universal answer to our climate and energy problems. Its advocates claim that it will become the primary source of the world's heating fuel, electricity, road transport fuel (cellulosic ethanol) and aviation fuel (biokerosene). Few people stop to wonder how the planet can accommodate these demands and still produce food and preserve wild places. Now an even crazier use of woodchips is being promoted everywhere (including in the Guardian). The great green miracle works like this: we turn the planet's surface into charcoal.

Sorry, not charcoal. We don't call it that any more. Now we say biochar. The idea is that wood and crop wastes are cooked to release the volatile components (which can be used as fuel), then the residue - the charcoal - is buried in the soil. According to the magical thinkers who promote it, the new miracle stops climate breakdown, replaces gas and petroleum, improves the fertility of the soil, reduces deforestation, cuts labour, creates employment, prevents respiratory disease and ensures that when you drop your toast it always lands butter side up. (I invented the last one, but give them time).

James Lovelock has a reply in The Guardian, noting that most sensible people would agree that creating plantations in the tropics in order to create charcoal is a bad idea, but that processing some existing crop wastes and using them for carbon sequestration is an entirely sensible idea - Lovelock replies to Monbiot on biochar.

I usually agree with George Monbiot and love the way he says it but this time – with his assertion that the latest miracle mass fuel cure, biochar, does not stand up – he has got it only half right.

Yes, it is silly to rename charcoal as biochar and yes, it would be wrong to plant anything specifically to make charcoal. So I agree, George, it would be wrong to have plantations in the tropics just to make charcoal.

I said in my recent book that perhaps the only tool we had to bring carbon dioxide back to pre-industrial levels was to let the biosphere pump it from the air for us. It currently removes 550bn tons a year, about 18 times more than we emit, but 99.9% of the carbon captured this way goes back to the air as CO2 when things are eat eaten.

What we have to do is turn a portion of all the waste of agriculture into charcoal and bury it. Consider grain like wheat or rice; most of the plant mass is in the stems, stalks and roots and we only eat the seeds. So instead of just ploughing in the stalks or turning them into cardboard, make it into charcoal and bury it or sink it in the ocean. We don't need plantations or crops planted for biochar, what we need is a charcoal maker on every farm so the farmer can turn his waste into carbon. Charcoal making might even work instead of landfill for waste paper and plastic.

George Monbiot has a classic column on some of the bizarre contradictions evident in the energy policies of the UK in particular and the West in general in this open letter to the King of Saudi Arabia.

King Abdaullah of Saudi Arabia

Your Majesty,

In common with the leaders of most western nations, our prime minister is urging you to increase your production of oil. I am writing to ask you to ignore him. Like the other leaders he is delusional, and is no longer competent to make his own decisions.

You and I know that there are several reasons for the high price of oil. Low prices at the beginning of this decade discouraged oil companies from investing in future capacity. There is a global shortage of skilled labour, steel and equipment. The weak dollar means that the price of oil is higher than it would have been if denominated in another currency. While your government says that financial speculation is an important factor, the Bank of England says it is not, so I don't know what to believe. The major oil producers have also become major consumers; in some cases their exports are falling even as their production has risen, because they are consuming more of their own output.

But what you know and I do not is the extent to which the price of oil might reflect an absolute shortage of global reserves. You and your advisers are perhaps the only people who know the answer to this question. Your published reserves are, of course, a political artefact unconnected to geological reality. The production quotas assigned to its members by Opec, the oil exporters' cartel, reflect the size of their stated reserves, which means that you have an incentive to exaggerate them. How else could we explain the fact that, despite two decades of furious pumping, your kingdom posts the same reserves as it did in 1988?

You say that you are saving your oil for the benefit of future generations. If this is true, it is a rational economic decision: oil in the ground looks like a better investment than money in the bank. But, reluctant as I am to question your Majesty's word, I must remind you that some oil analysts are now wondering whether this prudence is a convenient fiction. Are you restricting supply because you want to conserve stocks and keep the price high, or are you unable to raise production because your fabled spare capacity does not in fact exist?

I do not expect an answer to this question. I know that the true state of your reserves is a secret so closely guarded that oil analysts now resort to using spy satellites to try to estimate the speed of subsidence of the ground above your oil fields, as they have no other means of guessing how fast your reserves are running down.

What I know, and you may not, is that the high price of oil is currently the only factor implementing British government policy. The government claims that it is seeking to reduce carbon dioxide emissions, by encouraging people to use less fossil fuel. Now, for the first time in years, its wish has come true: people are driving and flying less. The AA reports that about a fifth of drivers are buying less fuel. A new study by the Worldwide Fund for Nature shows that businesses are encouraging their executives to use video conferences instead of flying. One of the most fuel-intensive industries of all, business-only air travel, has collapsed altogether.

In other words, your restrictions on supply - voluntary or otherwise - are helping the government to meet its carbon targets. So how does it respond? By angrily demanding that you remove them so that we can keep driving and flying as much as we did before. Last week, Gordon Brown averred that it's "a scandal that 40% of the oil is controlled by Opec, that their decisions can restrict the supply of oil to the rest of the world, and that at a time when oil is desperately needed, and supply needs to expand, that Opec can withhold supply from the market". In the United States, legislators have gone further: the House of Representatives has voted to bring a lawsuit against Opec's member states, and Democratic senators are trying to block arms sales to your kingdom unless you raise production.

This illustrates one of our leaders' delusions. They claim to wish to restrict the demand for fossil fuels, in order to address both climate change and energy security. At the same time, to quote Britain's Department for Business, they seek to "maximise economic recovery" from their remaining oil, gas and coal reserves. They persist in believing that both policies can be pursued at once, apparently unaware that if fossil fuels are extracted they will be burnt, however much they claim to wish to reduce consumption. The only states that appear to be imposing restrictions on the supply of fuel are the members of Opec, about which Brown so bitterly complains. Your Majesty, we have gone mad, and you alone can cure our affliction, by keeping your taps shut.

Our leaders, though they do not possess the least idea of whether the oil supplies required to support it will be sustained, are also overseeing a rapid expansion of our transport infrastructure. In the UK, we are building or upgrading thousands of miles of roads and doubling the capacity of our airports, in the expectation that there will be no restriction in the supply of fuel. The government's central forecast for the long-term price is just $70 a barrel.

Over the past few months, I have been trying to discover how the government derives this optimistic view. In response to a parliamentary question, it reveals that its projection is based on "the assessment made by the International Energy Agency in its 2007 World Energy Outlook". Well, last week the Wall Street Journal revealed that the IEA "is preparing a sharp downward revision of its oil-supply forecast". Its final report won't be released until November, but it has already concluded that "future crude supplies could be far tighter than previously thought". Its previous estimates of global production were wrong for one simple and shocking reason: it had based them on anticipated demand, rather than anticipated supply. It resolved the question of supply by assuming that it would automatically rise to meet demand, as if it were subject to no inherent restraints.

Our government must have known this, but it has refused to conduct its own analysis of global oil reserves. Uniquely among possible threats to the economy and national security, it has commissioned no research of any kind into this question. So earlier this year, I asked the Department for Business what contingency plans it possesses to meet the eventuality that the IEA's estimates could be wrong, and that global supplies of petroleum might peak in the near future. "The government," it replied, "does not feel the need to hold contingency plans." I am sure I do not need to explain the implications if its forecasts turn out to be wildly wrong.

Your Majesty, I recognise that this is not among your usual duties as the ruler of Saudi Arabia. But I respectfully beg you to save us from ourselves.

Yours Sincerely,

George Monbiot

KimiK pointed out in a comment on my Steampunk post that George Monbiot has been singing the praises of dirigibles lately In his article "Travelling Light", George considers the question "Is the airship a viable alternative to jet travel?".

Of all the charges levelled against environmentalists, perhaps the most unfair is the accusation that we are opposed to technological change. Most of the greens I know are fascinated by gadgets (sometimes to the exclusion of better solutions), while some of the people we confront seem terrified by new technologies, and react to them - witness the campaigns against windfarms - with irrational hostility.

But because environmentalists tend to have a feeling for material constraints, we recognise that solutions cannot be conjured out of thin air. In some cases they just don’t appear to exist. There are two reasons why we make such a fuss about flying. The first is that, even as governments promise to cut emissions, everywhere airports are expanding. In the UK, the government expects the number of airline passengers to rise from 228 million in 2005 to 480 million in 2030. Before long, there will scarcely be a patch of sky without a jet in it. The other is that there are no alternative means of propelling people through the air which are not more destructive than burning ordinary aviation fuel. Or so we think.

The airline companies prescribe two cures that are even worse than the disease. Even before they are deployed commercially in jets, biofuels are spreading hunger and deforestation. At first sight, hydrogen seems more promising. If it is produced by electrolysis using renewable electricity, it’s almost carbon-free. The prohibitive issue is storage. Hydrogen contains just a quarter of the energy as the same volume of jet fuel (kerosene), which means that planes could fly long distances only if they were filled with gas rather than passengers or cargo.

This means that if hydrogen planes are to fly commercially, they need much wider bodies than ordinary jetliners. According to the Royal Commission on Environmental Pollution “the combination of larger drag and lower weight would require flight at higher altitudes” than planes fuelled by kerosene. A technology that is green at ground level becomes an environmental disaster in the stratosphere. Hydrogen’s great advantage – that it produces only water when it burns – turns into a major liability: in the stratosphere, water vapour is a powerful greenhouse gas. The royal commission estimates that hydrogen planes would exert a climate changing effect “some 13 times larger than for a standard kerosene fuelled subsonic aircraft.”

But there is another use for this gas, though I am aware that it will go down like a lead balloon with most of my readers. The word airship elicits a fixed reaction in almost everyone who hears it: “what about the Hindenburg?”. It’s as if, every time someone proposed travelling on a cruise ship, you were to ask, “but what about the Titanic?”. Yes, there was a spectacular disaster – 71 years ago. It has lodged in our minds because, like the Titanic, the Hindenburg was bigger and plusher than any craft built before it, and it was carrying rich and prominent people. The conflagration was witnessed by journalists and broadcast all over the world. It also become the technology’s funeral pyre: the Hindenburg was doomed long before it burnt, as airships were already being displaced by aeroplanes.

Though the designs have changed, their disadvantages have not disappeared. While a large commercial airliner cruises at about 900 kilometres per hour, the maximum speed of an airship is roughly 150kph. At an average speed of 130kph, the journey from London to New York would take 43 hours. Airships are more sensitive to wind than aeroplanes, which means that flights are more likely to be delayed. But they have one major advantage: the environmental cost could be reduced almost to zero.

Even when burning fossil fuels, the total climate-changing impact of an airship, according to researchers at the Tyndall Centre for Climate Change Research, is 80-90% smaller than that of ordinary aircraft. But the airship is also the only form of transport which can easily store hydrogen: you could inflate a hydrogen bladder inside the helium balloon. There might be a neat synergy here: one of the problems with airships is that they become lighter - and therefore harder to control - as the fuel is consumed. In this case they become heavier. Michael Stewart of the company World SkyCat suggests burning both gaseous and liquid hydrogen to keep the weight of the craft constant.

Airships fly much lower than planes – typically at about 4000 feet – which means that their emissions of water vapour have very little effect on temperature. If they were powered by hydrogen fuel cells, they would be almost silent, greatly reducing the effects for people on the ground. Though they are slower than jets, the cabin can be built much wider, which means that travelling by airship would be rather like travelling by cruise ship, but at twice the speed and using a fraction of the fuel.

There are four small companies trying to get airships off the ground. Most of the new designs make use of aerodynamic lift as well as buoyancy (they are shaped like fat planes with stubby wings or tails) which means that they are heavier and more stable than the old dirigibles, and can land without help on the ground. They can alight on and take off from almost any flattish surface, including water. But all of them have a problem with flotation: of the financial rather than the physical kind. While the price of carbon stays low, companies have no financial incentive to switch to a different form of transport.

Airships aren't the only form of reversalism being considered for air transport as fuel prices rise - as I noted last month, turboprop aircraft are also making a comeback.