For most of the past couple of centuries of industrial capitalism, the majority of economists, politicians and citizens, in general, have taken energy supplies for granted. The exceptions were local energy constraints, periods of war and infrequent incidents of politically driven supply disruptions, such as the 1970s oil shocks triggered by the Arab oil embargo and the Iranian revolution.
But, in recent years, two huge challenges to our energy situation have loomed increasingly large and are forcing people to give energy the serious consideration it deserves. The first is anthropogenic climate change, which the majority of scientists ascribe mostly to the burning of fossil fuels. The second challenge – which is still the elephant in the room – is the rapid depletion of cheap and easily accessible reserves of oil, coal and gas.
A Dutch researcher writing on TheOilDrum.com website recently made available a useful data compilation providing global primary energy consumption by energy type (see diagram). An analysis of historical energy patterns shows an astonishing growth in energy consumption and highlights our current dependencies.
In 1830, the Industrial Revolution was just two generations old in Great Britain, was in its infancy in Germany and was still in gestation in the US. Total global energy consumption rose from about 24 exajoules (10^18 joules) in 1830 to over 550 EJ in 2010. In the past century alone, energy consumption grew by a factor of ten. On a per capita basis, energy consumption quadrupled between 1830 and 2010.
In 1830, biomass accounted for over 95% of the world’s energy supply. Even today, much of the poorer, developing world’s population still relies on traditional biomass fuels like wood and animal dung for cooking and heating. Despite the enormous growth in fossil fuel use over the past century, consumption of biomass energy has continued to grow each year, rising from 23 EJ in 1830 to 63 EJ in 2010. A surge in the last decade is largely the result of a huge expansion of ethanol and biodiesel production, driven mainly by government subsidies.
Britain was the first country to exploit its coal reserves in the late eighteenth century, at first mainly because it was running short of wood. Globally, coal replaced biomass as the largest source of energy as recently as 1905. Ironically, the fastest growth in coal consumption occurred in the early part of the new millennium, as China ramped up production to feed its breakneck industriali- sation.
Commercial oil production in the US began in 1859, but did not overtake biomass energy until 1955. Oil superseded coal as the dominant energy source in 1964, and still provides the greatest share of primary energy today at over one-third.
Natural gas has been the relative latecomer among fossil fuels, but has grown rapidly since the 1950s. Where it is abundantly available, it has become the fuel of choice for home heating and increasingly for electricity generation.
Commercial nuclear power generation, derived from the fission of enriched uranium atoms, began in 1954. It was historically the fastest-growing new energy source, taking just 12 years to progress from 1 EJ to 10 EJ. But nuclear power has levelled off since 2000, and faces an uncertain future after Fukushima.
Hydroelectricity generation kicked off in the 1870s but has grown very slowly, reaching 12 EJ in 2010. Other renewable electricity generation from solar, wind and geothermal energy sources amounted to just 2 EJ in 2010 – invisible on the diagram. This is equivalent to the energy obtained from coal in 1848 and from oil in 1912, shortly after the launch of the model-T Ford car.
The diagram clearly shows how dependent our industrial society is on fossil fuels. In 2010, 80% of the world’s primary energy supply was derived from fossil fuels, 11% from biomass, 5.5% from nuclear energy, 2.2% from hydropower and just 0.4% from solar, wind and geothermal energy.
Humanity is now reaching an epic turning point in its energy history. World conventional crude oil production has been basically flat since 2005, and unconventional oil and biofuels have only added marginally to production rates since then. An increasing number of analysts are expecting world liquid fuels output to begin declining within the next few years as discoveries of new oilfields cannot keep up with the depletion of old fields. And a number of recent academic studies have thrown serious doubt on the common assumption of abundant coal reserves.
Installed capacity of renewables like solar and wind has been recording spectacular growth rates of more than 20% a year for several years, but this is off an extremely low base. The transition from depleting and polluting finite fuels to renewable sources of energy represents a monumental and urgent transition for humanity.