This confluence of planetary factors ultimately fuelled the Industrial Revolution. Without the great Carboniferous coal measures humanity might have stalled in its technological development three centuries ago. We might still be using waterwheels and windmills, and tilling our fields with horse-drawn ploughs.
THE POLITICS OF COAL
There were many reasons why the Industrial Revolution began in Britain. The scarcity and rising price of wood (and thus charcoal) encouraged the substitution of coal as a fuel wherever possible. The economy of labour in Britain favoured the replacement of expensive craftspeople with machines which, although they required high initial capital investment, were more productive and required fewer workers to operate. And Britain’s empire provided cheap cotton from America and then India that prompted innovations allowing textiles to be more rapidly produced from fibres. So although in Britain the introduction of machines replaced human labour, it was slaves toiling in fields overseas who produced the raw materials like cotton that drove the process.
But Britain also benefited from a geological bonanza – mountains of easily accessible, good-quality Carboniferous coal lying underground waiting to be dug up – to literally fuel its industrialisation. By the 1840s, Britain’s coalfields were supplying so much energy that to match it using charcoal instead would have required burning 15 million acres of woodlands – an area equivalent to a third of the entire country – every year.21
The Industrial Revolution spread from its birthplace as tools, techniques and technologies for intensive coal mining and the mass production of iron and steel were adopted in mainland Europe. Here the same formation of Carboniferous coal that had fuelled Britain’s industry extends underground through northern France and Belgium to the Ruhr region of Germany. This was to become the industrial heartland of Europe: a coal crescent as central to modern history as the Fertile Crescent was to the ancient world.22 In North America, the transition to coal occurred much later: the far less densely populated colonies along the East Coast initially had access to huge areas of forest for charcoal,23 so American industry did not begin to replace charcoal with coal on a grand scale until the mid nineteenth century.24 Nonetheless, by the 1890s the US had surpassed Britain as the world leader in the production of iron and steel.25 In particular, Pittsburgh was well positioned within easy reach of iron ore, limestone for the flux, and the abundant coal measures of the Appalachian Mountains – a geological concurrence that made the fortunes of some of the richest tycoons of the modern capitalist era, such as Andrew Carnegie.
The 2017 UK election map (above) with Labour constituencies shown in dark, and the Carboniferous coalfields (right).
Today the collieries that fuelled the Industrial Revolution in Britain have virtually all closed, as remaining coal seams became ever more difficult to access, cheaper coal became available overseas, and less polluting or renewable energy sources were sought.fn5 A few opencast mines remain, but the last of the deep mines in the UK, Kellingley in Yorkshire, closed in 2015.27 Yet astonishingly, the distribution of the 320-million-year-old coalfields in the UK still leaves its imprint on Britain’s political map today.
The Labour Party was founded in 1900 from the trade union movement, with particularly close ties to British coal miners. And although it has changed a great deal over the last hundred years – from a party in the shadow of the Liberals to a landslide victory just after the Second World War to New Labour under Tony Blair – the deep link between coal and politics has endured for generations. Take the results of the most recent General Election, in 2017, for example, shown here. The election was much closer than the map would seem to imply, with densely populated, multicultural cities such as London tending to lean to Labour and the sparsely populated, larger, rural constituencies overwhelmingly voting Conservative. The result was a hung parliament with Labour winning 262 seats in parliament and the Conservatives 318 – not enough for a majority government.
But let’s look more closely at the distribution of Labour votes across the country. The figure here shows the location of Britain’s coalfields, and what is remarkable is the tight correlation between the political and geological maps. The broad coalfields of Cumberland, Northumberland and Durham (the Great Northern), Lancashire, Yorkshire, Staffordshire, North and South Wales, all match perfectly with the large areas of Labour constituencies in the election. This correlation was even stronger in the 2015 election, when Labour’s crushing defeat confined it to its heartlands, and the pattern is evident throughout the previous decades. Support for the main left-wing political party in the UK almost perfectly matches the regions of Carboniferous deposits.fn6 It seems that the old geology deep underground is still reflected in people’s lives today.
While coal remains a crucial part of the world’s energy mix, primarily for generating electricity and manufacturing steel and concrete, the politics of coal have now been largely superseded by those of another fossil fuel. Today, oil is one of the most valuable commodities in the world and the dominant energy source of humanity, making up a third of the total consumed by our global civilisation.28 Geopolitical tensions over its production and transport have dominated international relations for decades, and as we saw in Chapter 4, it is the major reason for the West’s interest – and interventions – in the Gulf and the naval chokepoints around the world through which the oil supertankers must pass.
BLACK DEATH
Like coal, we have used petroleum – literally, ‘rock oil’ – for millennia. Asphalt (bitumen) that had seeped up onto the surface was used as a cement in the construction of the walls of Babylon 4,000 years ago and as a road-building material around 625 BC.29 By AD 350 the Chinese were drilling oil wells and burning the fuel to evaporate brine to produce salt,30 and in the tenth century Persian alchemists were distilling petroleum to make kerosene for lamps. But it was not until the second half of the nineteenth century that we began to use oil on an industrial scale.
Crude oil is a hugely complex mixture of different-sized carbon compounds, which can be separated by distillation into different fractions. Early uses of these fractions included lubricants for steam engines and other machinery, and kerosene for lighting cities. But it was with the development of the modern internal combustion engine in Germany in 1876 that humanity’s oil consumption really took off.31 The gasoline refined from crude oil had previously been considered too volatile and dangerous to be of much use, but it proved a perfect fuel for powering the pistons of these new machines. Today we also use aviation kerosene for soaring over the clouds in our planes. The long hydrocarbon compounds in these liquid fuels pack in far more energy than coal and so represent fabulously dense and portable stores of power for transport.32 And not only does oil fuel our automobiles, it is also crucial to laying down the smooth roads on which we drive – viscous asphalt is composed of the longest hydrocarbon chain molecules in crude oil.33
Oil is so attractive because it ranges high on the Energy Return on Investment (EROI) index – that is, you only need to put a small amount of energy into extracting and refining it, but you’ll get a huge amount of energy out of it.34 It is also far more portable than coal: the liquid crude can simply be squirted down pipes over huge distances. It is this winning combination of high energy density, easy transportability and relative abundance that has turned oil into the most important source of energy in the world today. And it’s not just critical as a fuel. Around 16 per cent of its annual production is not burned but used as feedstock for a diverse range of organic chemistry, producing everything from solvents, adhesives and plastics to pharmaceuticals. Modern intensive agriculture would also be impossible without oil. It is used to synthesise pesticides and herbicides that control the artificial environment of farms for high yields, it fuels the tractors and harvesters that tend the fields, and artificial fertilisers are also made by using fossil energy. Oil feeds your car but you’re also drinking it with every meal.
While coal was produced by the Earth from the compacting and baking of an
cient swamp forests, oil and natural gas are formed from the remains of microscopic marine plankton. Life has been flourishing in the seas for far longer than plants have colonised the land masses, but most of the oil powering our twenty-first century civilisation was actually formed about 200 million years after the Carboniferous forests flourished. This oil was created in the now-vanished Tethys Ocean in two huge pulses about 155 and 100 million years ago:35 during the late Jurassic and mid Cretaceous periods.
The sunlit surface waters of the world’s oceans today are teeming with microscopic life made up by hordes of tiny critters collectively known as plankton. The primary producers forming the foundations of the oceanic ecosystems are phytoplankton like diatoms, coccoliths and dinoflagellates. These single-celled photosynthesisers grow by absorbing the energy of sunlight to capture carbon dioxide and fix it into sugars and all the other organic molecules they need; and just like land plants they release oxygen as a by-product. While the Amazonian rainforest is often referred to as the lungs of the planet, in fact it is the drifting multitudes of phytoplankton in the seas that produce most of the oxygen we breathe. And when conditions are just right for their growth, staggeringly dense populations of these cells amass in the water – the milky turquoise blooms of coccoliths are even visible from space.
The planktonic realm is also filled with zooplankton – microscopic grazers and predators such as forams and radiolarians. These microorganisms are able to extend little tentacles through pores in their elaborately shaped hard shells to ensnare and devour less fortunate plankton. Both phytoplankton and zooplankton are in turn eaten by fish, which are eaten by larger fish, or filtered out of the water in huge gulps by whales, and so they form the foundation of the entire oceanic food web. When the plankton cells evade their predators and die of natural causes, they are consumed by decomposition bacteria that recycle the carbon and other elemental nutrients back around the system. This planktonic ecosystem of primary producers, predators, scavengers and decomposers is as complex as the Serengeti with its grasses, gazelles, cheetahs and vultures, but all played out in microscopic miniature in the sparkling surface waters of the world’s oceans.
When plankton die they drift down through the water column to darker and darker depths, joined by slowly sinking mineral grains blown in by wind or washed in by rivers from the continents. This steadily settling precipitation of decaying organic matter and inorganic detritus towards the sea floor is known as marine snow. Even the deepest depths of today’s oceans are well oxygenated by the global circulation of seawater, and so most of the organic remains are digested by bacteria and the carbon recycled.
This is what happens across the great majority of the oceanic expanse today. But to accumulate organic debris on the seafloor, which eventually turns into oil, you need high planktonic productivity in the surface waters combined with limited oxygen at the ocean bottom, to prevent bacteria recycling the carbon so that it instead accumulates as a black, organic-rich mud on the seafloor (analogous to the conditions needed to build coal seams, as we saw earlier). This carbon-loaded mud then becomes buried under further deposits so that it is squashed and hardened into black shale rock. This is the starter material for crude oil and natural gas around the world. As the shale becomes buried deeper and deeper it is warmed by the interior heat of the planet, until it passes into what is known as the ‘oil window’ – a temperature range of about 50–100 °C. Simmering slowly, the complex organic compounds of the dead marine life are broken down into the long-chain hydrocarbon molecules of oil. If the shales are exposed to higher temperatures, up to about 250 °C, the deep chemistry breaks apart even these long chains into small carbon-containing molecules, mostly methane, but also some ethane, propane and butane – that is, natural gas. The oil window generally occurs at a depth of between 2 and 6 kilometres, and it can take the shale over 10 million years to become buried this deep by the continuing sedimentation above.
The enormous pressures at this depth squeeze the liquid oil out of its source rock and back up through the overlying strata. If it doesn’t encounter anything to block its vertical migration and hold it underground the oil simply seeps back out from the sea floor. Sandstone works very well as a reservoir rock, the pore spaces between the individual grains acting to soak up the oil like a geological sponge, and with a layer of, say, finely grained mudrock or impermeable limestone on top to act as a seal, the oil and gas becomes trapped, ready for us to drill down and suck it up.36
As we’ve seen, this process no longer happens in our oceans today. So what were the peculiar conditions in the ancient Tethys Ocean 100 million years ago that caused so much plankton debris to accumulate and become oil?
By the Cretaceous Period, the great supercontinent Pangea had fragmented and the continents were dispersing again. No longer was there a single massive landmass draped across the equator. Instead, the huge waterway of the Tethys Ocean stretched all the way around the midriff of the world, separating the northern and southern continents. This meant that the ocean circulation patterns were very different back then, with a current able to flow unhindered in a circuit around the whole world. This equatorial current bathed in the tropical sunshine and became very warm.
Indeed, the mid Cretaceous world was a broiling hothouse, with equatorial sea surface temperatures as high as 25–30 °C, and still a tepid 10–15 °C at the poles. No ice caps existed there, and Canada and even Antarctica supported dense forests. Without ice caps locking up large amounts of water, the sea levels were also much higher than they are today. In addition, lots of active rifting took place in the Earth’s crust at the time, opening up the North and South Atlantic as the continents pulled apart. As new oceanic crust is created in these seafloor spreading centres it is still warm and buoyant and the crust bulges up in great long ridges of submarine mountain ranges. These huge mid-ocean ridges displaced a great deal of water and the sea levels rose even higher. Indeed, the combination of hot climate and active seafloor spreading meant that sea levels were higher during the late Cretaceous than at any other period over the past billion years of our planet’s history – they were perhaps as much as 300 metres higher than today.37
Consequently, the ocean inundated huge areas of the continents: Europe was mostly submerged; the Western Interior Seaway flooded right up through the middle of North America from the Gulf of Mexico to the Arctic (as we saw in Chapter 4 when we looked at the voting patterns in the south-eastern US); and the Trans-Saharan Seaway swept down Africa from the Tethys through what is now Libya, Chad, Niger and Nigeria. Vigorous volcanism associated with the widespread rifting also released a lot of nutrients into the seas to fertilise plankton blooms. The late Cretaceous was therefore a world not just of deep ocean but also of shallow marginal seas, whose warm waters provided ideal growth conditions for plankton.
But conditions were also very different on the floor of these Cretaceous seas. In a hothouse world without polar ice creating cold, dense water, the thermohaline circulation that we explored in Chapter 3 was shut down: there was no global conveyor belt circulating water through the ocean depths. And crucially, warm water also holds much less dissolved oxygen, and any that did make it into the deep waters was readily used up by the decomposition bacteria.
Oil-forming regions in the anoxic seas of Cretaceous Earth.
The upshot of all this was that the Cretaceous sea floor became an oxygen-starved dead zone, where the bacteria weren’t able to properly break down the organic matter. At the same time, the frantic productivity of the plankton in the warm, sunlit surface waters produced a veritable blizzard of marine snow settling down to the sea floor. Without being decomposed, the organic material accumulated and became buried as more sediment settled down.fn7 As with the Carboniferous coal forests in subsiding swamp basins, the carbon recycling system in the Cretaceous sea floor had become broken, allowing organic matter to accumulate for tens of millions of years. As a result, the anoxic sea floor became a thick sludge of organic-rich mud, which turned into
extensive deposits of black shale rock. The period during which huge areas of shale accumulated in the Tethys Sea has therefore been called ‘the Black Death’.39
Our planet has seen both earlier and more recent episodes of formation of crude oil and natural gas, but by far the most prolific were the organic-loaded black shales deposited around the continental shelves of the Tethys Ocean during the late Jurassic and mid Cretaceous periods. The Persian Gulf, the most abundant region for oil and gas today, as well as the substantial deposits in western Siberia, the Gulf of Mexico, the North Sea and Venezuela, were all produced by the combination of geological processes at this time.40
CUTTING OUT THE MIDDLEMAN
While coal powered the Industrial Revolution and oil carried us into our modern technological civilisation, humanity’s exploitation of these fossil fuels has brought with it some now well-established global problems. Since the early seventeenth century we’ve been fervently digging up this buried ancient carbon that took tens of millions of years for the Earth to slowly stockpile, and we burned a great deal of it in just a few centuries. While there are concerns over peak oil and the diminishing supply of crude, there is plenty of accessible coal still underground – certainly another few centuries’ worth at current consumption rates.41 In this sense, then, we’re not currently facing another energy crisis but a climate crisis, born as a result of our past solution to our energy hunger.
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