Humanity has had exponential growth in population, knowledge, achievements and hope over the last 40 000 years. We have built wonders of the modern and ancient world. All achievements needed energy. Any achievements set forth in plans for the future must also consider the energy expense. The following table shows some of our progress to date.

Event Date Cost Manpower Effect
Egyptian Pyramids ~4000 BC[1]      
Stonehenge ~2000 BCE      
Assyrian invasion
of Egypt
671 BC     Over-extended nation
Greek Acropolis 500 BC      
Alexander the Great 400 BC Half a ton of silver talents a day for army pay   Needed to continue conquering to pay for army
Roman Expansion 200 AD 1 legion = 1.5M denari per annum 30+ legions Over-extended nation.
Coinage debasement led to inflation,annual budgets, and income policy
Teotihuacan 200      
Danegeld 800 40M silver coins   Prevented invasion. Forged single national currency
Crusades 1180 150 000 silver marks ransom   Funded by taxes on all moveable property and all income
Chinese Flotilla 1405   27 800 crew, 1180 ships Political stoppage caused China to receive European sailors rather than vice versa.
Spanish Armada 1580 4M ducats 130 ships South American plunder was squandered. English drew Genoan bills to reduce available loans
War of the Spanish Succession 1694     English invent ‘national debt’ and create Bank of England. Initiated perpetual loan at defined interest rate.
American Revolution 1776     General acceptance of paper money. Hyperinflation as no control of printing presses.
Napoleanic Wars 1815 £15M loaned by Britain to allies   Commercial banks main source of funding. Britain’s national debt grew from £273 to 816M
U.S. Civil War 1860’s $5.2B   Created state and income tax for federal revenue. Inflation reduced value of money by half.
Suez Canal 1869 $80M   Facilitated economy
Fanco-Prussian War 1871 5B Franc indemnity   Money raised through lending
Schloss Neuschwanstein/
1886 31.2M Marks   Bankrupts nation
Canada’s cross country rail line 1886 $150M, 59% by taxpayers   Joint private/public funding
Trans-Siberian line/ BAM 1905 and 1991 Trans-Siberian ? / BAM=$30B   Rail lines connected country
World War I 1914 10’sM £   1st billion £ loan
Panama Canal 1914 $400M   Facilitated economy
Hoover Dam 1935 $165M 21 000 Fully paid by power production
World War II 1930’s-40’s $288B for US millions 3% loan rate set as maximum in GB.
US national debt grew from $40B to 260B at 2.5%
Manhattan Project 1945 $2.2B 130 000 staff Expand technology
Apollo moon landing 1960’s $9.3B 300 000 staff Expand technology
Channel Tunnel 1993 £9B   Facilitate economy
Troll/Kollsnes 1996 35.5B NOK   Resource acquisition
3 Gorges Dam 2003 $25B+ US   Resource acquisition
International Space Station 2005+ $35-160B over 40 launches Expand technology
Jiaozhou Bridge 2011 $1.5 to 8.8B 10,000people, 450000tons steel, 2.3e6m3 concrete Reduce commute by 20 minutes
Fibre optic connection 2011 $300M   save 3 milliseconds travel
Lunar Development soon $25B 100’s of thousands Facilitate economy, expand technology, acquire resources

Telling is the increasing amount of energy and effort being now allocated to recovering stores of energy. Gone are the simple days of energy stores, petroleum, bubbling up out of the ground. Now it is pried from more and more difficult and hazardous places. Hence, the greater effort to obtain it. Eventually we will need more energy to obtain stores of energy than the amount of energy in the stores. At this moment, our supplies of energy stores will be effectively gone.

[1] Some people postulate that the pyramids were built by an agrarian community
during the previous inter-glacial warm period about 40 000 years ago. If true, this
is an example of a human civilization that rose to greatness and then completely vanished.


Humanity has had exponential growth in population, knowledge, achievements and hope over the last 40 000 years. We have built wonders of the modern and ancient world. All achievements needed energy. Any achievements set forth in plans for the future must also consider the energy expense. The following table shows some of our progress to date.

Event Date Cost Effect
Shanghai-Hangzhou 200km rail link 2010 $US4.35B Facilitate travel, showcase technology
Shanghai-Beijing 1318km rail link 2014 $US32.5B Facilitate travel, showcase technology
Macau gambling 2010 +$US13B Pleasure


Humanity needs energy to power themselves into the future. Energy fuels bodies and enables technology. Insufficient energy necessitates an inability to sustain people at the desired technological level. A sufficient energy supply means that the expected number of people will live a full life at a desired technological level.

From this description we see that we can undertake an assessment of the future of humanity using just three parameters; energy availability, number of people and technological level. We know the number of people on Earth continues to increase. The level of technology and its associated energy consumption equally increase. The limits to energy supplies on the finite Earth mean limits to both technology and number of people. Choosing an energy intensive future whether with large numbers of people1 or enhanced technology requires access to energy resources. Increasing the number of people or the amount and level of technology increases the demand on energy. Decreasing the supply of energy will decrease the number of people and/or their practicing level of technology.

People do live at different levels of technology. However, defining technological levels is more difficult than counting the number of people. Assuredly people are knowing and using a lot more technology than our erstwhilecavemen ancestors. However, aside from fictitious examples set in civilization styled computer games, there aren’t any definitive levels. Further, there are various degrees of technology in use throughout the world. In large cities of the developed countries, people drive cars, communicate over cell phones and often have a computer or robot aid them in their work. In developing countries there are villages where people exist in a manner that is little changed from their predecessors of thousands of years ago. Hence, aside from knowing that the knowledge and utilization of technology by some people increase, definitive levels don’t exist.

Nevertheless we can define qualified levels of technology. Further, we can estimate the number of people who live at this level. Last, we can estimate the energy factor2 associated with the technological level. The result is an estimate of the current energy demands for the current population. From this, we have an estimate of the total energy demand for all the people and all their technology levels.

Knowing the number of people and the levels of technology is interesting. Why is it pertinent to strategic planning for the future? The answer is twofold. One, it is people who perform the actions and do the work to complete projects3. Large projects like building the pyramids of Giza or unraveling the DNA structure of humans require thousands of people. Two, energy is needed both to power people’s body but also to power the technology. Sailboats, barges, levers and wheels were technological achievements likely employed in pyramid construction. Computers, microscopes and scanners are symptomatic of the technological aids for the DNA researchers. If we want to construct space stations or find a cure for cancer, we will need energy. Energy powers the workforce and the technology. Energy is critical in any strategic plan.

Making plans in a world with infinite energy and people is trivial. This situation is one extreme for planners of the future. It is a nice extreme as anything is possible. Here, happenstance can direct the choices as any wrong choices can simply be corrected. The other, more telling extreme is when the amount of energy is limited and can diminish to zero. In this extreme, plans are worthless as nothing is possible because no work or action is achievable.

We know energy on Earth is finite4. We also know that today we are bathing in a largesse of energy preserved from vegetation that captured the Sun’s rays over hundreds of millions of years ago on Earth. We will soon consume all the supplies of this non-renewable energy source5. Thus, any strategic plan for the future must consider not only the finite amount of energy stores available on Earth but also the fact that with today’s rate of energy consumption, we are living at a non-sustainable technological level. That is, the Earth’s renewable energy supplies cannot maintain the current number of people at their current level of technology. This shortfall in energy supplies will sorely affect the future so that planning may very well be an exercise in minimizing drops than supporting growths. At least this will be true until people return to using an amount of energy that is sustainable.

Given this prognosis we can proceed into postulating various strategic plans. We can decide on a plan that forsakes technology. We know that in the past there were millions of people who consumed no more energy than their biological needs. This was sustainable and perhaps we can return to this level if the associated supporting ecosystem can return to its previous level. Yet, this would obviate the progress of the previous tens to hundreds of thousands of years of advancement of our species. This is a possible plan but gives little credit to our species.

Aficionados of science fiction stories know well of another future. This one is dedicated to technology. All life on Earth is bent to promote an increased human population which uses their numbers to advance technology. In this future, all competitors to the human species, all other energy-using non-beneficial living things, are exterminated. This future optimizes humanity’s energy availability but leads to a sterile planet with little room for errors in ecology. With little knowledge or experience in deciding on the efficacy of other species, this future is hazardous but quite possible for humankind. However, if wrong choices are made, there is every possibility of ending humanity’s future.

The optimum future likely lies somewhere between these two extremes. A future without technology or a future with only technology leads to too great a risk of no future for humanity. Any strategic plan for our species must take into account the supply of energy, an achievable level of technology and the survivability of our species.A strategic plan which accomplishes all this just may be the best route for survival. At least, it will be better than letting happenstance decide our future.

Qadesh – 1300 BC

The mighty empires of the Pharoah’s and the Hittites came to blows about the year 1300 BC near the town of Qadesh in Syria. The town of Qadesh is about 600 km from the centre of power for each of these kingdoms. The typical army speed of the times was 25 kilometres per day. Therefor each army needed about 30 days to get to battle and 30 to return (i.e. a 60 day campaign).

Lengthy battles seldom occurred as most ended in 2 to 3 days. The construction of provisions could well be the reason.

In this late bronze age, battles were often fought after the harvest time of May. With the serfs being freed of chores, the leaders put them into the army and headed out to make war. This all came at an energy cost.

Hittite energy costs

In their army, they had;

  • 3700 chariots each with 3 horses
  • 40 000 infantry

A man marching with full gear would need 3600 kCal a day. Similarly, a horse pulling a laden chariot needs about 25000 kCal of digestible energy a day. Given this and assuming that the number for the Hittite infantry includes their charioteers then their daily energy needs would be;

Men + horses = 40000×3600 + 3700x3x25000 = 4.2×1011Calories each day.
And for the campaign of 60 days, the total energy needs would be 2.5×1013Calories.

Egyptian Energy Costs

The Egyptian logistic issues were similar to the Hittites. Each kingdom’s centre was about equal distance from the town of Qadesh hence each had to travel the same distance. Also each army likely traveled at the same pace so their traveling time would be the same. In the Egyptian army there were;

  • 4 corps of 5000 men each
  • Each corp included 4000 infantry and 500 chariots each with 2 charioteers running two horses.

Their total energy expenditure is thus;
Men + horses = (4000×4 + 500x2x4)x3600 + 500x2x4x25000 = 1.72×1011Calories.
And for the campaign of 60 days, the total energy needs would be 1.0×1013Calories.


The total energy cost would be about 3.5×1013 Calories (8.36×1012joules) though this assumes all the people and horses who went to battle also returned. This amount of energy is on the same scale as the amount of energy needed to launch the space shuttle into orbit.

This is a huge quantity of energy but only includes food. The energy needs to dress each person, build the chariots and manufacture all the spears, bows, arrows, and knives would increase this amount.

Energy Source

The energy source is the net primary production in the area. This must be a surplus from that needed to feed the farmers, administrators and other support elements for the army. Today’s wheat yields about 3.5×109 calorie per tonne. Ancient wheat, without the genetic refinement, likely was less than a tenth the source of energy, or 3.5×108 calories per tonne. Therefore, this campaign would need 10 000 tonnes of wheat (assuming all food came from wheat). The going rate was about a tonne per hectare so the campaign would need the excesses from 50 000 hectares (or 500 square kilometers.
I.e. a tenth the area of present day Lebanon).

Caesar and the Rhine 56BC

Julius Caesar, man of his times, undertook and completed many wondrous accomplishments during his tenure in consul in Rome. In June 56 BC, he took his legions into Gaul to further subjugate the locals. But, his aggression resulted in the slaughter of hundreds of thousands of local. In a show of political propaganda and military strength, he built a bridge to allow his army to cross the Rhine river and for the first time, extend Rome’s influence directly into the territory of the Germanic tribes.

Engineering a bridge has never been trivial and the Romans had little historical precedence to build upon. Nevertheless, they were master engineers and had the necessary material at hand. With his 40000 men and the surrounding forest, Caesar created a solid platform for his force to safely cross the Rhine river and undertake a few weeks pillage.

Caesar recounts this amazing endeavour within his diaries. Within, he graphically describes using huge stones to ram logs into the river bottom and then laying long timbers to establish a support and platform.

This undertaking utilized energy through a number of ways. The men had to be feed. The trees contained large quantities of energy to grow. And the effort to chop, clean, move and install the wood added to the total.

Caesar had 40000 men work for 10 days thus needing 1.3e13 Joules.

Assume Caesar used fir trees. Multiplying the energy content of each with the likely number of trees results in an energy content of 8.8e13 Joules.

Felling and clearing the trees would use considerable effort but is difficult to measure. However, Caesar spoke of a stone pile-driver pushing the logs into the river bottom. Lifting and dropping the stone the likely number of times results in an energy expenditure of 2e7 Joules.

The rough energy total for building the bridge is 1e14 Joules. This is greater than the energy needed to loft the space shuttle into orbit. It is approximately the same as the energy released by the atomic bomb dropped on Hiroshima.

Sadly, given that the bridge was for propaganda purposes rather than practical purposes, Caesar destroyed it on his return.