What would a world without fossil fuels look like?

15 October 2014 by Michael Le Page
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What's the historical alternative to coal and gas? (Image: Michael Kirkham)

Our advanced civilisation is built on easily exploited coal, oil and gas. New Scientist explores an alternative history that holds lessons for us all

YOU are probably reading this on a piece of ex-tree. Felled by a petrol-guzzling chainsaw, it was carted to a paper mill in a diesel-powered truck. Or perhaps these sentences are on a tablet, with plastic components that started life as crude oil, and metal smelted with coke produced from the tar sands of Canada. Either way, the words are probably lit with electricity from a coal-fired power station. Maybe you are even sipping wine, grown with fertiliser made using natural gas, in a glass created in an oil-fired furnace.

The list goes on and on. Our civilisation is built on fossil fuels. We depend on them not just for energy but for all kinds of raw materials and even the food we eat. Weaning ourselves off this stuff is not going to be easy.

But what if there were no fossil fuels on Earth, or at least none that were easy to exploit. Would history have taken a different course? What of the industrial revolution? Would modern civilisation even exist? To tackle such questions, we must go on a journey that will carry us from medieval times into a counterfactual yet strangely familiar world. It's a fascinating thought experiment with implications for the future of our own planet, as well as for alien civilisations.

A long time ago we weren't too bothered about fossil fuels. Early civilisations sometimes used them if they were there for the taking, but did not rely on them. Wood or charcoal were superior for just about all purposes. In medieval Europe, only Britain began to use coal on a large scale. Why? The answer has to do with geography, argues historian Rolf Sieferle of the University of St Gallen in Switzerland.

In the 13th century, water transport was cheap. Floating wood down a river required almost no energy, and a single horse could pull a barge weighing 50 tonnes. Going overland was far more difficult: a horse could pull only 1 or 2 tonnes. If wood had to be hauled any distance, its price rose rapidly. This was bad news for Britain, which lacked the long navigable rivers of continental Europe. What it did have, though, were large outcrops of coal right next to the river Tyne in northern England, which could be loaded on to ships and taken by river and sea south to London.

Coal was regarded as a dirty, stinky fuel that wrecked people's health. But in Britain it became cheaper than wood, and caught on because it could replace wood for many purposes – making lime for mortar, firing bricks, heating homes and so on.

Yet raw coal is inferior to wood in one crucial way – it is no use for smelting copper or iron ores. The impurities in coal weaken the metal. Instead, smelters relied on charcoal, says Benjamin Roberts of Durham University in the UK, who studies early metallurgy.

Then, in the 17th century, English inventor Hugh Plat suggested that coal could be purified by "charring" it – a process called coking. In 1642, brewers began to use coke for malting, achieving a new lighter roast that led to the production of the first pale ale, and in 1709, Abraham Darby started using coke to smelt iron ore, ending the dependence on charcoal. This, some argue, was the pivotal innovation that kick-started the industrial revolution in the 18th century, by providing a plentiful supply of cheap iron which led to many other innovations such as iron railways.

Before the 18th century, the main source of energy was the solar power captured by plants – biomass. The energy needed to pull ploughs or haul loads came from the food consumed by animals or labourers. The heat for cooking, heating and industry came mainly from wood. Plants were also the ultimate source of many raw materials, from wool and cotton to timber for houses and ships. Other materials, from cement to iron, couldn't be made without burning wood or charcoal. This meant that as populations grew and energy use rose, land area became a limiting factor. Negative feedbacks kicked in. If charcoal burners used more wood, there was less for building and ship making. If more trees were planted, there was less land for growing food.

Plenty of things could be done to relieve these constraints, from better growing practices such as coppicing to trading with neighbouring countries or taking land by force. But as growth continued, the limits were soon reached again. "Expansion in one area meant contraction elsewhere," says historian Tony Wrigley of the University of Cambridge.

Exploiting coal, however, gave us access to a virtual forest bigger than all the continents put together – millions and millions of years of accumulated plant growth. It's a finite resource, but one so vast we still haven't exhausted it.

New iron age

Coal enabled Britain to produce iron cheaply, without large forests. Iron farm tools boosted productivity and iron railways made it cheaper to move that food and other goods. "There were positive feedbacks," says Wrigley. "Each advance made the next more likely."

Here's how important coal was: by the 1820s, growing enough wood to replace all the coal used in Britain would have required a land area larger than the country. "It is inconceivable that there would have been a development worthy of the name industrial revolution based on charcoal," Sieferle writes in his book The Subterranean Forest: Energy systems and the industrial revolution.

What if we had no coal or other fossil fuels? By the 19th century, says Sieferle, the growth constraints imposed by limited land area would have kicked in. In earlier civilisations, periods of rapid advance were often followed by collapse, he says. "There was no collapse in Europe because we had fossil fuels."

Clearly, a world without fossil fuels could not develop far without an energy source that does not depend on biomass. There are many other potential energy sources – the key question is whether any can be exploited without advanced technology.

For a start, we can rule out nuclear power and solar photovoltaics. By contrast, solar thermal power is easily exploited to heat air or water using little more than black pipes. An array of mirrors can focus enough heat to melt metal. But even today exploiting this on an industrial scale is a huge challenge. In a world without fossil fuels, the sun might be used for cooking or heating homes and water, but as an energy source for industry it's probably not viable.

That leaves wind and water. On the sea, wind powered most trade and exploration until well into the 19th century. On land, wind and water mills have been used for at least 2000 years. In medieval Europe the technology reached new heights. By around 1600, wind and water mills were grinding grain, sawing wood, boring pipes, polishing glass, drilling holes, pressing seeds for oil, grinding up stones, pumping out mines and more. It was in these mills, some argue, that the foundations for the industrial revolution were laid.

Water continued to power factories throughout the industrial revolution. It wasn't until 1820 that coal-powered steam engines overtook water as the main source of mechanical power in British factories, says Terry Reynolds of Michigan Technological University in Houghton, and author of Stronger Than a Hundred Men: A history of the vertical water wheel. "In the US, the date was around 1870."

Factories turned to coal in part because they were using pretty much all of the available water power already. Most factories had to be located near ports and navigable rivers, where hydropower resources are limited. "In Britain in the late 18th century some streams were so dammed up that no further power could be squeezed out of them," Reynolds says. There were vast untapped hydropower resources in distant hills and mountains, but there was no way to get the energy to where it was needed.

In our world, two technologies changed this. First, pioneers like Michael Faraday worked out how to transform motion into electrical power. Later in the 19th century, engineers worked out how to transmit electricity over long distances. "Electric power transmission transformed hydropower into a vital contributor to the modern world's power mix," says Reynolds.

It seems clear, then, that to develop on the basis of hydropower rather than fossil fuels, a civilisation would have to develop hydroelectricity. Is that feasible?

Without fossil fuels, western Europe could have developed technologically to around the 1800 level, Sieferles thinks. This was the time when innovators like Faraday and Humphrey Davy were developing the basic components of modern electrical technology.

So where would this alternative path take us? Forget steampunk: this would be a hydroelectropunk world (see " Alternative Earth"). For a start, industrialisation might have taken off in the mountains of Norway or Switzerland rather than Britain. Without easily exploitable fossil fuels, economic and technological development, and population growth, would certainly have been slower. Regions with abundant hydropower resources, including Scandinavia, Canada and parts of South America and Africa, would have had a huge advantage (see map).

Without dirty coal fires, cities would not be grimy and smoke-stained. Driven by the need for better hydroelectric generators rather than more efficient steam engines, science would focus more on electrodynamics than thermodynamics, perhaps hastening the development of smaller, lighter electric motors and batteries.

The pace of life would also be slower – going from London to New York would involve weeks spent on an iron sailing ship rather than hours on an aeroplane. The world might even be more equitable: without steam power, some European nations may have struggled to establish vast empires. Most important of all, there would be no impending climate doom.

It is an appealing vision, but perhaps an unlikely one. We tend to assume that technological progress is inevitable, but it may not be. China started smelting iron with coke as early as the 9th century, for instance, but the industrial revolution did not happen there. It happened in Britain only because a very particular set of geographic, social, economic and cultural factors came together.

Hydroelectricity is a more complex technology than steam power, and even if developed by a pre-industrial civilisation there are reasons to doubt that it could drive an industrial revolution. With relatively simple technology, electricity can be used for lighting, heating, cooking, powering engines, making fertiliser and even melting metals. However, while electric power can reduce the amount of charcoal needed for smelting iron by more than half, it cannot replace it entirely. So wood would still be a limiting factor, and without cheap iron to make tools, machines and railways, rapid industrialisation would be extremely difficult.

Dam them all

Scaling up hydroelectricity is also more challenging than scaling up coal mining. It was possible to build dams long before the industrial age. In 1177, for example, the 400-metre-long Bazacle dam in Toulouse, France, was built to power water mills. In 1888, it was converted to a 4-megawatt hydroelectric power station.

However, it would take 2500 dams of this size to provide the same amount of energy as England and Wales extracted from coal at the beginning of the 19th century. To match coal consumption in 1850, it would take another 8000 dams. And what do you construct them with, asks Sieferle. Building materials like cement and bricks became cheap in our world only because we could use coal to produce lime for cement and to fire bricks. Then there's the energy needed to transport materials. Building hydroelectric dams takes a lot of planning and labour and energy, and yet the dams don't provide energy until they are finished. The economics might not add up.

So could civilisations make the transition to advanced industrial economies without exploiting fossil fuels? "You cannot exclude this, of course," says Sieferle, but he doesn't think it likely. Historian Kenneth Pomeranz, author of the The Great Divergence: China, Europe, and the making of the modern world economy, is more optimistic. "My guess would be slower growth," he says. "But there are obviously a lot of unknowns." And slower growth is not without its dangers. Regional civilisations are vulnerable to epidemics, famine, earthquakes, war and volcanic eruptions – the downfall of many. The longer it takes for a global industrial society to emerge, the more chance that disaster will strike.

All this hints at a universal truth: wherever technologically advanced civilisations develop, most – perhaps all – do so by exploiting fossil fuels. "You can't change anything without expending energy," says Wrigley. "Energy is an absolute prerequisite."

Fossil fuels probably exist on most worlds where carbon-based life might thrive (see "Do alien worlds have fossil fuels?"). Perhaps there are aquatic alien civilisations that have progressed technologically without exploiting fire, or even some that flourish on worlds with no oxygen in the atmosphere, but it's hard to imagine how this could happen.

If fossil fuels are key to developing advanced technology, global warming may not be a uniquely human problem but an issue for petrol-heads across the universe. The laws of physics apply everywhere, after all. "The downside of access to a stock of energy in fossil fuels is very great," says Wrigley. "And making the transition to other energy sources is far from easy."

How many alien civilisations have wrecked their planet or run out of fossil fuels – or both – before they managed to make the transition to sustainable energy sources? This could even be the "great filter", says James Kasting of Pennsylvania State University, who studies what makes planets habitable. Kasting refers to the idea that our failure to discover intelligent life elsewhere despite the vast number of stars – the Fermi paradox – is due to some bottleneck that either stops intelligent life evolving, or makes it go extinct.

After such a collapse occurs, there would be no easily exploitable fossil fuels left. There might a brief window of opportunity for a civilisation to re-establish itself using more sustainable energy sources, before all knowledge and resources have been lost. But after that, it will be too late.

If this is right, each planet essentially offers one chance to make the transition to an advanced and sustainable state. We had better not waste ours.

What would a world without fossil fuels be like? An industrial civilisation could only develop if it could tap some energy source other than biomass, and hydroelectricity looks like the only possible alternative (see main story). This means electricity would be the main power source. Trains would be pulled by electric locomotives. In cities, electric trams and trolleybuses would probably dominate. Electric cars might cruise the asphalt-free roads too – there were, after all, already 30,000 electric cars in the US by 1912 – but with their limited range there would be no call for motorways.

In our world, cheap fossil fuels killed off early renewable energy technologies. In a hydroelectric world, they would probably continue to develop. Wind mills would be a common sight, providing valuable extra energy. Biofuels and hydrogen might be produced, too, as technology advanced – biogas from manure could power tractors on farms, for instance – but liquid fuels would be far more expensive than electricity. Which means there would be no passenger aeroplanes. Airship flight would be possible, but with hydrogen-filled craft only, as helium is derived from natural gas. International trade and travel would rely largely on sailing ships, perhaps fast, metal-hulled ones like the Preussen, built in 1902. On land, canal networks would be far more extensive and important.

This alternative world would have familiar challenges, too. Extensive damming would cause many environmental problems and conflicts. "Wars might be fought over sites with water power potential instead of over oil," says Terry Reynolds of Michigan Technological University in Houghton. And without coal, the greater demand for land for producing materials and fuels might lead to even greater deforestation than in our world.

The World Without Fossil Fuel

What would a world without fossil fuels look like?

New iron age

Dam them all