Rebecca Hosking: Farms Without Oil using Practical Permaculture.

Rebecca Hosking is well known as a wildlife photographer and journalist, and also for her campaign against plastic bags. Modbury, in Devon, is the first plastic bag-free town since, at her instigation, all 43 traders there pledged not to sell them or give them away to customers for a minimum of 6 months [1]. It was Hosking's experience in photographic wildlife that spurred her to this campaign stance, having witnessed first hand the plight of albatrosses strangled by plastic, and dolphins and seals struggling to live, wrapped in plastic and parcel tape. I confess I was only vaguely aware of this effort and her name was brought to my attention recently through a TV documentary [3], set on the Devon farm of her formative years, which addresses the issue of how we are going to feed everyone in the absence of cheap oil. I made some notes during the programme and I see that she published a text about it in The Daily Mail newspaper, as referred to below [2].

In summary, practical permaculture, involving reconstitution and preservation of natural habitat, including hedgerows, where there is biodiversity and interacting "layers" of flora and fauna that pass down nutrients between levels, and bugs and earthworms that naturally till the soil, result in a fertile and high-yielding crop ecosystem, that is more productive than conventional agriculture; and all of this without oil or other artificial energy inputs. One day a week's worth of harvesting and around 10 days a year of maintenance is all that is necessary to keep such a system going, rather than the drudgery of farming that was the case before cheap oil. I grew up in agricultural regions, first of South Wales and then the English West Country (Gloucester) and my memory of farming and farmers is that even with oil, theirs was a life of comparative slog.

One drawback is that cereals cannot readily be produced by this means, and so a change of diet to one richer in fruit and vegetables is also necessary. Hosking notes that she had always thought of hedgerows as being simply divides between fields, and indeed that was my view too. I remember my first flight in a plane and seeing the English countryside is as though someone had drawn lines of division between the different fields, as their various individual hues and shades seemed to confirm; almost like a watercolour patchwork. However, the hedgerows not only provide habitat for birds who add a contribution of nitrogen through their droppings to the ecosystem, but are crop-productive entities in their own right - a kind of vertical field. I tend to think of the majority of arable land in the sense of flat fields, with occasional trees here and there almost as a kind of garnish; yet in reality, the most fertility is found when the landscape is effectively a forest (as most of Britain once was until the trees were cut-down to make ships and charcoal for smelting iron) with occasional clearings cut through it.

Farming has undergone a revolution during the past century, especially after WWII, as driven mainly by cheap energy in the form of oil-based fuel and chemical fertilizers. This has profoundly changed the shape of the countryside. Life on a small farm prior to then was indeed a life of drudgery. Even organic farms depend on oil, and for the reasons of imminently running short of cheap oil and potentially the effect of burning fossil carbon fuels on climate change, we are going to have to do without them or with far less of them. Colin Campbell is an oil industry insider and expert and is it his opinion that the break-year was 1981 when the world began to use more oil than it found new oil. Indeed, less and less new oil has been discovered during the past 40 years.

The precise date of peak oil doesn't matter so much, but we need to face the inevitability of a 2% annual decline in oil production. However, the present curb in new oil development infrastructure means that the decline could be a lot worse than this, and a 9% fall is one scenario that has been suggested, which means effectively a collapse of everything that depends on oil within a short time of a few years. All in all we need to act now.

Our dependence on oil and gas may be illustrated by the familiar ham sandwich, as normally provided in a pristine plastic wrapper. There is diesel needed to run the tractors that harrow the land, and dig seed in to grow grain to feed the pigs on. Then there are chemical fertilizers and pesticides, herbicides and insecticides, all of which are made from natural gas. Once the grain is harvested, it is dried using big heaters, powered probably by electricity made from natural gas, or they are gas-heaters themselves. To make the ham the pig eats around half a tonne of grain per year, and to complete the sandwich the salad is either flown-in from elsewhere in the world or produced in a heated greenhouse. It is then driven miles in a refrigerated lorry. The plastic package is made from oil and takes fossil energy to produce.

The Soil Association are rightly concerned about not only the state of our soil but of agriculture more generally, and predict there will be an energy famine by 2013 at the latest. i.e. by 2013 we will no longer be able to make as much energy as we will demand to maintain the status quo. It is thought that by 2013 Britain's energy account will be in the red to the tune of £500 billion, but if there is not enough energy available in any case, it is not simply a matter of whether we can pay the bill or not.

So, the question is, how can we farm - feed everybody - without oil? Richard Heinberg, author of the aptly entitled The Party's Over, with a nice piece of cover-art where someone is holding a fuel-gun to his head with the last drops of oil dripping from it, in an implied act of suicide, thinks we have left it too late to find alternatives and that all forms of renewable energy can't match the amount of oil we use at 30 billion barrels a day. Pretty well this is also my conclusion, as you have read through the workings of these articles. I began writing this blog in a spirit of optimism, assuming that we could do without nuclear power, and that all our energy could be provided using wind, wave, biofuels and whatever else, but I now think we will need all forms of energy we can get our hands on to tide us over the very difficult transitional period when we adapt and learn to use far less energy. Either way, by design or default, we will end up living entirely differently from how we do today. It is not a matter of "going-back" since that small-farm agrarian lifestyle was miserable and soulless for the majority who had to live it, but a localisation of our interests, economies and activities to do more with less and maybe feel a reconnected sense with one another and with nature. Otherwise a lot of us are going to die.

Currently, it takes 10 calories of energy to produce 1 calorie of food energy. The Green Revolution, that has confounded the Malthusian predictions that world population would outstrip our capacity to grow enough food to feed it, is underpinned by cheap energy, particularly from oil. Genetically Modified (GM) crops depend as much on oil as any other - you can grow more on the same area of land but this requires a commensurate increase in the input of fertilizers and fuel for farm machinery. If there is an energy famine, the United States and Australia could collapse as food exporters, and cause world famine and huge price rises in what food is available. Most of the skills in how to farm without fossil fuels have been forgotten: a good example of this the the series Victorian farm, shown on B.B.C. 2 recently. Here a team of three spent a year living and farming as Victorians, and the roles are rather traditional: Ruth Goodwin looks after the cooking, the housework - it takes practically the full week to do all the washing and ironing - and the poultry, including killing them when their time is up; while the two men learn to plough with heavy horse, build a pig-sty, harvest the crops and hay and between the three of them they do everything using at best hand-operated technology which was an innovation of Victorian engineering, hugely labour-saving than without them, but still all heavily manual.

I watched this series in wonder, but with the simmering sense of fear that we might have to return to that way of life, and if so, how could we cope with relearning so many forgotten skills, and indeed all the hard manual work. It is work for young men, at best, and the average age of a British farmer is now 60. The Victorian equivalent of a tractor was the heavy horse, so called because they weigh up to one ton and are powerful but amiable beasts. A modern tractor has a power equivalent to 400 horses, while in pre-oil times they had at most (if they could borrow another for very hard work) two horses. Indeed, the present level of energy consumption around the world, at 18 TW is equal to 22 billion slaves (the world population is 6.7 billion) working around the clock.

The farming industry has been left to die in the U.K., and the country imports around 40% of its food - brought in using oil-powered transport. The cost of such carriage can only increase and ultimately fail, as oil prices rise inexorably. There are only 150,000 farmers left in the U.K., and as noted, with an average age of 60 years. Animals need to be brought in in winter otherwise they destroy the pasture. To feed them hay needs to be harvested and this is the biggest use of energy on a small farm. At Fordhall farm in Shropshire, the cattle are kept out all though the winter, where they graze with very little in the way of additional feed being needed for them. This rendered the brother and sister team Charlotte and Ben Hollins who run the farm, almost immune to the recent oil price shocks that hit the rest if the industry hard. Their trick is to use a range of grasses natural to the area and which in combination make the land surface tough, so that it is something like a wild prairie and able to withstand the constant pummelling by the animals hooves during the winter. Choosing the best kinds of grass is an empirical matter, and whatever works best for a region is the one to select. Other kinds of grass will fit with another area: again, local knowledge is likely prove indispensable, probably in old farming records.

Their father, Arthur Hollins, a lifetime farmer, recognised that the woodland on the farm was much richer in wildlife than the fields he cultivated, leading him to believe that ploughing destroys essential nutrients in the soil by exposing them to sunlight. As Hosking notes:

"The flocks of gulls and crows squabbling behind the plough for worms and beetles is just a childhood memory for me. Today, the birds don't follow the plough because the soil is dead and there is nothing for them to eat.

"The only way modern agriculture can get away with killing the life in the soil is through the another use of fossil fuel - by turning it into chemical fertilizer containing nitrates, phosphates and potash."

At least 96% of all food grown in Britain relies on farming methods that use synthetic fertilizer, without which the soil lacks enough nutrients for anything to grow in it, and without ploughing the soil is not aerated. This seems like a stalemate situation until rather than a conflict with nature, lessons are drawn in harmony with the natural world, which was lush 10,000 years ago before humans began ploughing fields. That earthworms are able to till and aerate soil was known to Charles Darwin, and that they have done so for millions of years. Forests are able to flourish without the agricultural impact of humans, because they rely on a natural fecundity which is created by billions of microbes (bacteria), fungi, animals, birds and plants. This is the importance of biodiversity: an interconnected, holistic symbiosis of living organisms. Before the fifteenth century, most of Britain was forest-land, and most if the energy expended in preserving modern agriculture is to hold it in an artificial bubble; from returning to its natural forested state.

Chris and Lyn Dixon have a permaculture smallholding ("Forest garden") in Snowdonia, on which they are able to produce all the fruit, vegetables and meat they need, and even the fuel to cook it. The site looks like a set of small clearings in a mass of woodland, in reverse of what we normally now think of as the layout of a farm, with clumps of trees surrounded by fields. A natural woodland is like having half a dozen fields stacked one on top of the other. It works on different levels: shrub, etc., fruit trees, tree canopy, which recycles nutrients - e.g. nitrogen in leaf litter, beneficial fungi and root systems. It is reckoned that 10 people can be fed per acre (25 per hectare), or about double that by conventional agriculture. Cereals can't be grown and so it will be necessary to adapt our diet to other foods: nuts grow on trees, as in chestnuts and hazelnuts at a yield of 2 tonnes/acre which is a similar yield to wheat although from a nutritional standpoint, nuts are similar to rice. For the U.K. to become self-sufficient we need to eat less meat.

Gardening with hand tools is more energy effective (and labour intensive) and raises five times as much food on a given area in a small garden than is produced on the same area of open field. It is likely that a preponderance of small plots will take the place of fields as the latter decline in the face of a loss of oil and natural gas supplies. An analogy can be drawn with the "digging for victory" campaign of World War II, with its allotment gardens. Overall, we need more farmers, otherwise we will starve. There are just 150,000 left now and we will need around 11 - 12 million, i.e. every family will be involved rather than just those running a collection of industrial-scale farms.

Rather than asking the question, could permaculture feed Britain, it is more salient to ask whether conventional agriculture can. The answer to the latter in the long run, is no, because it depends so utterly on oil and gas, and so the only course of action is to try permaculture. It takes a long time for soil to regenerate, but if left to its natural state it does. Every plant is important in some way: e.g. bracken collects potash, birch encourages phosphate recycling through the ecosystem. Nitrogen, potassium and phosphorus are all circulated through the system by nature - animals, including worms - and so no energy input is necessary. Some creatures help with pest control whole others control drainage and others pull up nutrients from the soil; all are important in this symbiosis of biodiversity. Birds that eat insects and seeds accumulate phosphates which are returned to the soil in their droppings thus eliminating the need for rock phosphate fertilizers, world supply of which peaked, incidentally, in 1988.

According to Richard Heinberg, "The dominant demographic trend of the 21st Century is going to be re-ruralisation (or de-industrialisation). That is not to say that the cities will disappear, but the proportion of people involved directly in food production is going to increase. We will also need a lot more full-time farmers - otherwise what are we going to be eating?"

If we dug for victory during the German U-boat blockade in World War II, there's no particular reasion we can't do it again in the face of a war against declining oil.

Will homo sapiens (as his name implies) be wise enough to survive.

Related Reading.
[1] http://www.guardian.co.uk/society/2007/may/16/business.waste
[2] http://www.dailymail.co.uk/news/article-1145431/Now-farm-help-teach-world-live-oil-says-woman-banished-plastic-bags-town.html
[3] BBC 2 broadcast, Natural World. A farm for the Future. Friday, 20th February 2009, broadcast 20.00.

Norwegian Power.

I have just returned from a visit to the Norwegian capital of Oslo. This is a very cultural city, and at this time of year, cold, crisp snowy and quite beautiful. I had not seen much of the painter Edvard Munch's work before (apart from The Scream - Skrik - which has been the subject of a couple of high-profile robberies), but this is the place to see it. A Norwegian friend told me that in a crisis of faith, Munch simply stacked his canvases outside his house in all weathers, with birds shitting on them. Now, of course, they are worth millions! Such is the fickle world of art. There is a good collection (with the shit washed-off) in the National Gallery and also in the Munch Museum. Like Vincent van Gogh, Munch's work seems to vibrate with a profound internal energy that seems to draw the viewer in, forging a connection with it. I am now a great fan of Munch, I must say.

There are just 4.8 million people living in Norway, more than 500,000 of them in Oslo. Despite its small population, compared to the U.K. which has around 60 million citizens, Norway has a land area of 385,000 km^2, or around half as much again as the British mainland. While Norway only ranks seventh in the list of world oil producers, it is reckoned to be third in the league-table of oil-exporting nations. Put another way, Norway produces a lot of oil and sells most of it, and is hence a very rich but expensive country; much of this wealth is invested into pension schemes and other means for social benefit. Hence, I believe it will become a magnet for those from other parts of the world seeking a better quality of life, as Britain has. Indeed, living in Britain now, Norway looks an attractive prospect to me.

Now Norwegian oil is not limitless, any more than our own UK provision is. It is reckoned, at least on a simple R/P ratio basis (which is a naive but crudely indicative analysis of relative resource holdings), that Britain has 6 years worth of oil left and Norway 9 years left. If you are in Oslo, a very hands-on place to visit is the Norsk Teknisk Museum, which is bit like our Science Museum in London, and which I preferred before it became thematic. I liked to be able to just wander around according to my own will. Nonetheless, the Norwegian technical museum also is arranged around themes of exhibition.

In the medical theme section, for example, is the treatment of lesions on the backs and limbs of children caused by tuberculosis, by focussing ultra-violet light from an exposed carbon-arc onto them. The apparatus is nakedly apparent. There are photographs of the nurses as they administered this treatment wearing goggles made from darkened glass. I suppose they had learned the hard way that ultraviolet light causes blindness, in fact by bleaching the cornea. There are also radiographs (x-ray photographs) of babies in the womb, taken at quite (I reckon 7 or 8 months) late stages of their confinement. The date 1897 seems to stick in my mind, when it was not known that radiation was harmful, until the radiographers began to suffer from cancers of their hands and fingers, necessitating the steady amputation of fingers, then hands and eventually arms, by when the subject likely had heavily invasive cancer. Death usually followed quickly, as for Thomas Edison's assistant, Clarence Daly who died aged just 38, after years of suffering, from handling x-ray tubes, finally with both arms amputated. What radiation dose the babies received is anyone's guess but it would have been large.

There is another theme on "Energy". The Norwegian industrial age began with the building of a hydroelectric power station and in consequence of its bestowal of waterfalls, the generating capacity from hydropower rose from 70 MW in 1906 to 1,270 MW in 1920. By 1970, all Norwegian homes were provided with electricity, and now some 98% of all Norway's electricity is made from hydropower, a total of 27.5 GW (27,500 MW). Norsk Hydro ASA, which began operating in 1905, is a Norwegian aluminium and renewable energy company, based in Oslo. It is the fourth largest integrated aluminium company worldwide and has outlets in 40 countries around the world and on all continents. The Norwegian State holds a 43.8 percent ownership interest in the company, with around 28,000 people on its payroll. Until October 2007, Norsk Hydro had a major presence in the oil and gas industry, until this division was merged with its rival Statoil to create StatoilHydro. StatoilHydro is the biggest offshore oil and gas company in the world and the largest company by revenue in the Nordic Region.

Before 1960, the huge oil resources off the long Norwegian coast were unknown, but U.S. exploration was successful in 1969 with the discovery of the first oil-field , Ekofisk. The Norwegian government allowed foreign companies rights to find and exploit the first of the Norwegian fields but thereafter demanded a strong presence and the subsequent take-over by new Norwegian companies like the state-owned Statoil. Very sensible of them!

Only time will confirm how much oil can be extracted form the North Sea, either under British or Norwegian territorial waters, but if Norway does have a mere 9 years of oil left, it still has plenty of natural gas, as was first discovered on the Norwegian continental shelf in the 1980's. Among the other wonders of the Teknisk Museum is an example of a gas-pipe, 42" in diameter, as is used to take gas from the Sleipner gas platform to Zeebrugger, as part of a gas-transportation network that moves 85 billion cubic metres of gas from Norway to Europe annually.

There is much negotiation about who will get new supplies of Norwegian gas, and whether some of it will come to the U.K. or go to mainland Europe. Most likely it will simply go to the highest bidder, and in these unpredictable economic times who that is, in the future, is anybody's guess.

Related Reading.
[1] http://en.wikipedia.org/wiki/Hydroelectricity#Countries_with_the_most_hydro-electric_capacity
[2] http://en.wikipedia.org/wiki/StatoilHydro
[3] http://en.wikipedia.org/wiki/Norsk_Hydro
[4] http://www.norsk-teknisk.museum.no/

Mammoth Threat from Methane Melt.

In terms of the geological record, we are presently in the Holocene epoch, the previous Pleistocene period having given-way around 10,000 years ago. This practically coincides with the end of the last ice-age, and massive flooding which is thought to have resulted in the creation of the Black Sea by a spill-over from a surging Mediterranean Sea. There is much speculation as to what exactly caused this transition, during which many of the earth ecosystems changed, and the region presently labelled as northern Siberia was highly populous in large animals like mammoths, woolly rhinoceroses, yaks and hippos. In contrast to other northerly areas, which were subject to repeated climatic assaults, this Siberian region was largely protected from the erosive advance and retreats of ice-sheets. What did occur, however, was the accumulation of silt, dust and the creation of ice-based tundra, which in some parts were mostly forest, and in others mainly mosses thrived.

Now, it has been assumed that it was climate change that reshaped the region, but a new perspective has been offered by Sergey Zimov, who is the director of the Northeast Science Station at Cherskii, which is located in the Republic of Sakha (Yakutia), leading to the demise of the large animals there. He turns the argument on its head, and reasons that they were hunted to extinction and it was the loss of the animals that resulted in the ecological transformation there. To test this notion, Zimov's team of researchers are reintroducing animals such as bison, horses, and eventually tigers, among other species in an effort to reconstitute the Pleistocene ecology. If it is successful, the strategy will support another example of the way human activities can impact on the environment. Rather than this being a castigation I do sometimes muse that maybe part of the reason that humans are on earth is to change it, as part of some grand design.

The northern ecosystem originally stretched from France and on across the Bering Strait to Canada and from islands in the Arctic over as far as China. It was big. Over the million year duration of the Pleistocene epoch, the ebb and flow of the ice-sheets ploughed the lands of most of northern Europe and North America, while northern Siberia remained largely untouched. At the same time that the herds of herbivores disappeared in their millions, the grasslands on which they depended also vanished. Holocene vegetation is dominated by moss and shrubs, in contrast to the Pleistocene megafauna, and has insufficient transpiration of moisture to dry-out the soil. When soil is saturated with water, the decomposition of biomass is inhibited and so are the nutrients required to underpin plant growth.

In contrast, when mosses are decomposed, the land becomes overgrown with grasses within a short time of perhaps one to two years. These grasses then dry-out the soil through rapid transpiration and create a steppe-like ecosystem. When herbivorous populations are low, the grass remains uneaten and it builds-up on the surface of the soil, thus shading it and reducing its fertility. Thus mosses and shrubs with relatively low water and nutrient needs become dominant. When the mammoths thrived, in the winter the animals ate the grasses from the previous summer's growth, and throughout the year they kept the soil productive with their dung and also trampled down mosses and shrubs thus preventing them from taking hold.

We now get to the interesting part in relation to climate change, which may be influenced by what happens in northern Siberia, in particular to its permafrost. In total, these frozen soils, with an average carbon-content of around 2.5%, encapsulate around 500 Gt of potentially mobile carbon. This amounts to two and a half times the carbon in all the world's rainforests combined. It is known that the tundra permafrosts are melting, and when the soil does thaw, microbes will begin to convert that long-held soil carbon into carbon dioxide (if there is oxygen present) or to methane under anoxic conditions. Methane would in principle be worse, since it has around 100x the global warming potential of CO2, and could cause a potential feedback mechanism where consequently rising temperatures melts more of the permafrost and releases more GW gases, at least so the argument goes.

Can the restoration of Pleistocene ecology, in which grasses and their root systems stabilise the soil, put the brakes on this process? Indeed, can stabilising the soil prevent the permafrost from melting? Probably not. Millions of herbivores surely also emit large amounts of methane, which must be offset against the gain in albedo of the earth from maintaining these frozen lands, which reflects solar radiation back into space. There are many factors involved in the global warming scenario, all of them interconnected. However, looking toward nature to find solutions to our energy and climate problems is I believe the way to go.

Related Reading.
http://www.faculty.uaf.edu/fffsc/park.html.

Low-Carbon Retrofit for a Quarter of British Homes.

In the thinking that 25% of the U.K.'s carbon emissions come from homes, it is planned to refurbish around seven million of them, thus curbing CO2 emissions in line with government targets to cut one third of emissions from this sector by 2030 and saving increasingly precious fuel. Yes I know, it's another of those long-way-off dates, and far enough away that who knows what kind of mess we will be in in terms of our energy provision and requirements or if anybody has any money to pay for it by then?

The move is likely to be applauded by energy poverty action groups (you are in energy poverty if you spend 10% or more of your disposable income on energy) and environmental campaigners concerned about anthropogenically induced climate change. Now the latter theory has fallen into a quite acrimonious debate, and the likes of James Hansen are being called alarmist (or worse), since there is credible scientific evidence that shows the whole global warming phenomenon to be shall I say, less clear-cut than we are generally led to believe. I noted the other day that Hansen's old boss has come clean that he isn't totally convinced any longer by the "it's all our fault" rhetoric. Given the huge impact on resources that will be necessary to adopt low-carbon, and carbon-capture strategies whether the issue is right or wrong is no affair of mere semantics.

However, while I await the conclusions of experts on this, it is clear that curbing carbon fuel use must mitigate global warming if indeed this is the cause of it, but more immediately it will ameliorate the terrible threat of running short of conventional fuels if we do indeed transfer our needs to renewable energy sources. I am skeptical about how quickly we can install millions of wind-turbines etc. but a move to a biomass economy (bioeconomy) insofar as this is possible does seem the way forward, since we can begin growing stuff immediately: it is however the processing of it into fuel and chemical feedstocks on the grand scale, requiring vast new engineering that is the real challenge. However, in an economic downturn of conventional production and commerce, might this not be an opportune time to begin honing such new developments, both to drive the economy and to prepare for an inevitable future with far less oil?

We will need to reskill our population at some stage for practical tasks and now seems as good a time as any to begin doing that. It would also be a good time to look at what exactly the universities are turning-out in terms of graduates, in measure against what skills the country actually does need, rather than a bums-on-seats policy that simply makes the government's unemployment statistics look less bad than they would otherwise. In all likelihood the new universities will return to their useful job as the polytechnics who trained the workforce for industry. When manufacturing industry "fell" in the 1970's/early 1980's, that manufacturing base was "lost" and it seems to me that now is the moment to kick-start a new industry based on biomass/renewables and the more efficient use of energy in buildings and for whatever level of transport provision we need in a revamped, relocalised society.

More small scale (e.g. CHP) low carbon heat systems are to be encouraged, probably by financial incentives - tax breaks etc., although since the Sustainable Energy Academy estimates that if home-owners spend £15,000-20,000 on their carbon-improvements, they would recoup that in fuel savings over a period of 10-15 years, or sooner if fuel prices increase, as they almost certainly will, it is the punter who will bear the burden. Entire districts may also be offered community clean energy schemes, or a mass refitting with more efficient energy devices. The Conservatives take the idea of "self-help" a stage further and might award grants of up to £6,500 per household, which would be recovered over up to 25 years from expected average reductions of £160 in annual gas and electricity costs.

I find a similarity here with the self-help "go to university" scheme (also known as loans and top-up fees), where a customer (they are not students any more) ends up owing an average of £15,000 - 20,000 in exchange for that piece of paper whose worth must yet be proved in the rapid skid of a world whose future cannot be guaranteed by past outcomes. We are now in entirely unassailed territory.

Related Reading.
http://www.guardian.co.uk/environment/2009/feb/09/eco-homes-refit-emissions
http://blogs.telegraph.co.uk/milo_yiannopoulos/blog/2009/02/17/leading_climate_change_cheerleader_james_hansen_has_lost_the_plot

Newcastle Coal Gas.

Miller's Elements of Chemistry is in three volumes, Part 3 of which deals with Organic Chemistry. What I love about Miller is his detailed and practical description of the aspects of his world in 1856, and for example he goes into great precision on the subject of coal and coal gasification. He tells us that for illuminating gas Scottish coal is best, since it contains higher hydrocarbons [e.g. in modern parlance that would be ethene (ethylene), ethane, propane etc.] which burn to give carbon particles and emit light from the flame. He says that coal from Durham - Newcastle Coal - is the best for making town gas to be burned as a fuel. The expression "bringing coals to Newcastle" is a reference to the huge production of coal that went on there at one time, and that it is superfluous to bring more since no one would want it, hence a metaphor for any unworkable or unmarketable enterprise.

Miller quotes that one ton of Newcastle coal yields 9,250 cubic feet of gas and 13 cwt of coke. One cwt is a "hundredweight" of which there were 20 to the ton and so the quantity of coke amounts to 65% of the initial charge of coal into the retorts.

There are 35.3 cubic feet (cu. ft.) to the cubic meter (m^3) and so that ton of coal yields 9,250/35.3 = 262.0 m^3 of a gas with a "specific gravity" of 0.410. The latter is referenced to air and so if one m^3 of air has a mass of 1.20 kg, the equivalent volume of coal-gas has a mass of 0.410 x 1.20 = 0.492 kg. Multiplied by 292.0 m^3 this gives a total mass of 128.92 kg.

The Imperial "long ton" amounts to 2240 pounds (lbs) or 1016.05 kg (or 1.01605 tonnes). Thus the mass gas yield is 128.92/1016.05 = 12.7%.

The difference between 65% coke plus 12.7% gas and the initial ton of coal leaves 22.3% which we may attribute to coal tar.

I noted in the previous posting that one m^3 of the gas of the composition quoted there has a mass of 536.69 kg, and if a similar quantity of it were produced by retorting one ton of some coal, this amounts to a similar 262.0 x 0.53669 kg/1016.05 kg = 13.8%. The somewhat (9%) higher mass of the gas in the latter case may be due to the presence of more higher hydrocarbons, which will increase its calorific value slightly, or to carbon dioxide which will reduce it.

Related Reading.
"Miller's Elements of Chemistry", Part III. Organic Chemistry", John W. Parker and Son., London, 1855.