against Nature. Thus trouble arises in the whole
body; this is why I tell you: be in harmony.
The Gospel of Mary Magdalene
I want to begin in Cambridge, where I was an undergraduate over forty years ago. One of the colleges at Cambridge University is called Peterhouse. It was founded in 1284 and is the university’s oldest surviving college. Its medieval architecture is today among the most precious in a city that is unusually rich in striking historic buildings. Alongside portraits of past Masters of Peterhouse, the college hall is decorated with fabric hangings designed by William Morris. He was a leading inspiration in the nineteenth century for the romantic Arts and Crafts Movement, having set about rediscovering the lost techniques of embroidery, stained-glass window making, illumination and calligraphy, textile dyeing, printing and weaving. He did this as a defiant reaction to the roughshod commercial expansion of machine-based manufacturing of the time. Morris was not against machines. He was concerned about what machines were being put to do and was horrified by the human degradation of work in the nineteenth-century factory and how the land was being ruined by industrial pollution. He also lamented that art and beauty had no place in this factory-based world and felt that, as a consequence, human dignity lay in ruins. On the ancient stone walls of Peterhouse’s hall his work seems very much at home.
Some time after Morris completed these designs and they were placed there, they were joined by more modern fittings, symbols of the age of industrialization that he was so concerned about. Most visitors today would hardly give them a second thought: they are the hall’s electric lights. What makes them special is that they were the first to be switched on anywhere in the university. In the country as a whole they were second only to those in the Houses of Parliament the year before. They were installed at the insistence of the scientist John Kelvin to mark the six-hundredth anniversary of the college in 1884. The electricity for the lights came froma generator powered by a steam engine that was in turn powered by gas derived from coal.
The installation of electric lighting at Peterhouse marked a dramatic departure from the previous 600 years, during which the college hall had been lit by candles, oil lamps (most likely including those powered by the blubber of whales) and wood fires. The steady, yellowish electric glow that we now take so much for granted also signalled a new dawn, not only for the college but for the whole world: the age of electricity and mass-produced power had arrived. It marked perhaps the most significant turning point in human history, and what may indeed prove to be the most significant in the recent history of all life on Earth.
Pioneer Run Creek, Titusville, Pennsylvania, USA, in 1865. One of the world’s first oil fields. From small beginnings, nearly every aspect of our lives is now dependent on fossil oil and gas.
When those lights first illuminated the shady, cool recesses of Peterhouse’s ancient hall, the world’s human population had reached about 1.2 billion. Although horses were still an indispensable source of power, the steam railway that reached Cambridge in 1845 had already led to a revolution in attitudes to travelling. A year after the great switch-on at Peterhouse, the first patent for a petrol-engine car was granted to Karl Benz in Germany. Eighteen years later the first plane would take to the air. In the expansive fenlands surrounding Cambridge, much of the drainage system that had been dug in Roman times had for centuries been powered by the wind. But even in these remote East Anglian flatlands times had changed. Some sixty years before the switch was first thrown to light Peterhouse, the last of some 800 wind pumps had been closed down, to be superseded by steam-powered alternatives. The obsolete technology was quickly swept away in favour of more flexible and powerful modern alternatives.
I make these points in order to underline the recent rapid pace of change, and to remind us of how quickly we have reached the point where we are now. All of these wonderful innovations were developed with the best of intentions. Pioneers like Benz wanted to create wealth and well-being and to improve people’s lives. But the huge benefits we have gained have not come without serious consequences. One of the biggest is on view up the road from Peterhouse, in a different part of Cambridge.
Ice core data has enabled scientists to build up a detailed long-term picture of carbon dioxide, methane and oxygen isotope levels in the atmosphere, and how average temperatures have changed.
Inside the headquarters of the British Antarctic Survey is what is without doubt one of the most remarkable archives ever accumulated. Kept in a building with a temperature permanently maintained at below –20° Celsius are tubeshaped sections of ice. They are about two feet long and some four inches in diameter. Some are white, others translucent. Meticulously labelled and filed on racks, these frosty samples were taken from the core of a drill that had penetrated one of the thickest layers of ice found on our modern Earth: an area called Dome C, high on the plateau of East Antarctica. As snow accumulated over thousands of years, it built up in deeper and deeper layers. The snow was compressed by subse-quent falls and the weight formed layers of ice, year after year for hundreds of millennia.
If the ice cores drilled out of Dome C were laid end to end they would stretch for about two miles, but it is not so much the depth the drill reached that is most remarkable: it is the age of the ice it found at the deepest levels. The further the drill went down, the older the ice it extracted, at the bottom pulling up samples more than 800,000 years old. The ice drill thus enables us to look back over the best part of a million years and so in a way is a time-travel machine.
Trapped in the falls of ancient snow are tiny bubbles of the Earth’s atmosphere as it was when the snow fell. When I last visited the centre, one of the scientists took an ice sample into the warmer corridor, where it began to melt, and I could hear it crackle as the bubbles of trapped air were released. By catching and analyzing these little bits of frozen air, scientists at the British Antarctic Survey have been able to take direct measurements of different gases. By analyzing different oxygen isotopes in the ice itself they can calculate accurate temperature measurements and these confirm that during the past three-quarters of a million years or so our world has undergone eight separate ice ages, each punctuated by warmer interglacial periods, like the one we are living in today.
One of the most dramatic findings to emerge from the study of these ice cores is how the levels of carbon dioxide have changed, and how closely they have matched the climate changes. Even in the warmest periods, the ice cores show that the concentration of carbon dioxide never went above about 290 parts per million – that is 0.029 per cent by volume of the air. In the 1780s, when the Industrial Revolution began in England, that figure stood at what was then a recent high point of about 280 parts per million. But the ice cores show how this figure has increased, and fast. A hundred years later levels had crept up to just below 300 parts per million. Another hundred years later, in the 1980s, carbon dioxide levels exceeded 340 parts per million.
Ice core data has enabled scientists to build up a detailed picture of carbon dioxide, methanol and oxygen isotope levels in the atmosphere and how average temperatures have changed.
Today there are more than 50,000 large power stations in the world, most of them burning fossil fuels to do what was done at Peterhouse in the 1880s – but now on a vast global scale. Between then and now the emissions we produce by generating energy in this way have grown from virtually nothing to billions of tonnes of carbon dioxide every year. And as the demand for power increases, so the number of coal- and gas-fired stations also goes up. In China and India today
