Homo Sapiens and Energy (Part 1)

It should not come as a surprise to any, I hope, that Homo Sapiens are dependent upon energy for survival. The National Health Service recommends that a man needs around 10,500kJ (2,500kcal) a day to maintain his weight and that a woman requires around 8,400kJ (2,000kcal) a day to maintain hers. That, of course, only takes into account fuel consumption to maintain our weight. It does not include the energy consumed to keep us warm, to cook our food, to build our shelter, to fabricate products and transport those same goods (and ourselves) to market. From 0 Common Era to 2000 Common Era the Homo Sapien population has expanded like this;

Chart 1

That means a whole lot of energy consumption. And look at that spike beginning just before 1800 CE – coinciding nicely with the Industrial Revolution. Not only did the Industrial Revolution (starting around 1760) replace hand production with machine production it also demanded that Homo Sapiens shift their energy dependence from wood to coal to power the machines. The following graph not only shows the alterations in energy type per year but also the quantity consumed (chart from the excellent website OurFiniteWorld.com run by Gail Tverberg drawn from information by Vaclav Smil estimates from Energy Transitions);

Chart 2

But why should coal consumption translate into an increase in world population? After all, the people weren’t eating coal. Prior to the Industrial Revolution came the British Agricultural Revolution (beginning around 1700) brought about by the most unlikely of heroes – the turnip. The turnip went where most other crops dare not venture, deep under the soil. The point, of course, is crop rotation. Crops of various root depth and nutrient demands could be rotated annually to improve soil fertility. This in turn increased land productivity which increased crop yields allowing the population in England and Wales to grow from 5.5 million in 1700 to over 9 million by 1801. The increase in productivity allowed a share of the farm labour force to move to urban centres finding work in the predominantly textile industries. Water and steam powered machines were then developed which increased the productivity of the labour force thus commencing the Industrial Revolution. This fed back not only into the creation of industrialised agricultural practices, but also allowing imports of various fertilisers from abroad by steam ship to improve soil quality. The point of all this is not simply to recite history but to show both Homo Sapiens’ dependence upon energy and display the types of fuel we consume.

Chart 3

Chart 4

So where are we today?

Judging from the last graph it is obvious that Homo Sapiens can add numbers to its population far easier that it can increase energy available for consumption. The question now becomes, ‘what next?’

The dip in energy consumption per capita between 2006 – 2009 coincides with both the 2007 – 2008 Financial Crisis and the Great Recession of December 2007 – June 2009. Indeed the inability to grow global energy consumption per capita across the globe resulted in reduced Gross Domestic Product thus exposing the banking system to the fragility (dare we say stupidity?) of the loans it had made to clients who could no longer afford to repay them. With the crisis ‘ending’ in 2009, the world has resumed a steady increase in energy consumption per capita, albeit at a much slower rate – most likely due to the lowest interest rates in financial history, even negative in some nations.

The point of all this is that our financial system cannot survive under a prolonged period of energy contraction. This, as a biological species, should not surprise us. Our Fate is intrinsically linked to the energy available to us.

Up until 1800 CE Human societies consumed mostly biofuels. With the introduction of steam powered machines Human societies consumed coal in increasing quantities until it overtook biofuel consumption around 1910 CE. If both our biofuel and fossil fuel reserves are reaching the point of exhaustion then what type of society will we live in when the remaining energy available is mostly nuclear with a dose of renewables? Will it even be a biological civilisation? For, if without natural gas products to fertilise our soils, how will Homo Sapiens continue to prosper? Just as Humans utilised steam powered machines to usher in the Industrial Era, will the Industrial Era utilise nuclear powered machines to usher in the Post-Human Era?

And why should we make this assumption – that our soils will no longer be able to sustain 7.5 billion Homo Sapiens (let alone the 11.2 billion that the UN expects by 2100)?

The ability to grow our population itself lies upon one of two assumptions;

  • Our soils can sustain this increase in population
  • We can find other methods to supplement our dependence on soil

Currently our plants are heavily reliant on artificial fertilisers to improve both plant health and yield to feed the current population of Homo Sapiens. Were this not the case fertilisers would not be needed at all as plants could extract all of their nutrient requirements from the soil. Fertilisers provide the three main macronutrients that plants require for healthy growth;

  • Nitrogen (N)
  • Phosphorous (P)
  • Potassium (K)

Nitrogen fertilisers are typically produced from ammonia (NH3) using natural gas (CH4) and nitrogen (N2) from the air. The ammonia is then used to produce nitrogen fertilisers such as ammonium nitrate. Sodium Nitrate (NaNO3) can also be used as a nitrogen fertiliser where it is mined in the Atacama desert in Chile.

Phosphate fertilisers are typically made from phosphate rock. It is necessary to convert these phosphate rocks into water-soluble phosphate salts by treating them with either sulfuric or phosphate acids.

Potassium fertilisers (usually referred to as ‘potash’) are a mixture of potassium minerals such as potassium chloride, potassium sulfate, potassium carbonate and potassium nitrate.

Fertiliser use has increased 34.4% from 2002 to 2014 with an average annual growth rate of 2.54%. The growth rate of the Human population over the same period is 1.2%.

Chart 5

So why should we think that this trend will reverse? After all, all dips (e.g. 2009) have been temporary. The only means of reversion will come through reduced extraction of the core resources. This can happen when resource scarcity drives cost above what the consumer can afford. Part 2 will explore the resource contraction that awaits Homo Sapiens.