Multiple stressors are converging to make the current industrial food system increasingly unsustainable and vulnerable to perturbations. Of course, the food system is in and of itself a leading cause to what is now threatening its future survival. Climate disruption, freshwater depletion, biodiversity loss, soil erosion and falling EROI on fossil fuels all point to the demise of industrial agriculture. This is well understood by biophysical economists and systems ecologists but often neglected in public or political discussions about food security. Most agricultural policies worsen the problem by making small-scale local agroecological farming unprofitable. Thus dooming large swathes of the population to become reliant on a dying system that costs more than it provides in terms of surplus energy.

There is a big misconception in the world about how modern technology has made us more efficient in agriculture. We think that big machines and lots of fertilizers are a better use of resources than employing more people. While large scale farming may seem efficient at first glance our perceptions are opposite of reality. How efficient the production of food is depends on the amount of energy expended on its development. The EROI, Energy Return on Investment, shows us the true nature of our efficiency in producing and consuming food. 

In hunter-gatherer societies, the relevant EROI metric is the caloric value of the food captured or gathered, versus the caloric expenditure of the hunt or gathering expedition. Studies of hunter-gatherers show an EROI of 10:1 to as high as 50:1 (Glaub 2015, Glaub & Hall 2017) depending on effort and final consumption. Large prey eaten directly by the hunting party only would yield a large energy profit while meat provided to support the hunters families would yield lower EROI ranging between 16:1 to 6:1. Nevertheless, this relatively large energy profit ratio probably allowed for the leisure time often associated with gathering societies. But limited capacity for food storage and settlement hinders development of a larger society. 

High population and overexploitation of resources was likely a driver of early domestication. In pre-industrial agriculture, dependent on peasant farmers, the EROI was 5:1 or less (Day et al. 2018) as it required intense efforts over long periods with often variable results. Much time was spent on production of food, fodder and fuelwood. But farming had the benefit of food storage which led to established settlements and concentrated labour. Fuelling population growth and specializations. 

Early industrialized societies benefited from high EROI from fossil fuels and large energy surpluses. Capital and energy substituted for labour. Food, fodder and fuel could be provided with fewer workers, permitting an expansion of non-primary sectors. The range of goods and services expanded. In the United Kingdom, energy and food expenditures fell to 20% as a proportion of GDP in 1830 from 50-80% prior to the industrial revolution (Day et al. 2018). But EROI of global oil reached its maximum value of 50:1 in the 1930s and has fallen since then to about 10-15:1 today (Court & Fizaine 2017). Modern industrial high-tech agriculture now consumes a staggering 10 calories of energy for every calorie of energy (food) delivered to the market, i.e. EROI of 1:10. Rending much of agriculture a net energy loss and completely unviable without fossil fuels.

Another great systems theory based book on why nations fail is out. This time its academic, journalist and writer Nafeez Ahmed, who long wrote for the Guardian but now has his own crowdsourced news site (Insurge-intelligence), who has delivered the goods. 

In his book, "Failing states, Collapsing systems: Biophysical Triggers of Political Violence", Nafeez presents the essential data on resource depletion, net energy decline, economic stagnation (debt bubble) and ties it nicely together with the acceleration of civil unrest around the globe. It's a big picture analysis of how the triple crises of energy, climate and food production impact societies around the world. A current example, according to Ahmed, of how these multiple stressors interact and can lead to systemic failure is war torn Syria. 

Syrian oil production peaked in 1996 while population, and thus consumption, kept increasing. By 2008 the government, who relied on petrol money for maintaining the state budget, had to slash fuel subsidies which tripled the price of petrol and food almost overnight. A huge deal to anyone already spending almost half of their income on food. At the same time as an ongoing drought in the eastern part of Syria devastated harvests and drove people from the countryside into the cities. Yemen experienced a similar fate of depleting resources, peak oil, and the resulting high vulnerability to shocks. Based on these two cases it takes about 15 years for a country that experiences its peak in oil production before additional pressures, such as climate change, contribute to systemic failure. 

It's not only the Middle East. Many other countries, for example Mexico,  are well on their way of having little to no extra oil to export for keeping their budget in balance or pay for subsidies that people depend on. And the counties who are still able to import some oil or have some mix of energy sources to depend on will be a target of immigrants looking to flee bankrupt and failing nations. Which in turn will fuel the nationalist sentiments and a grab for what's left, military interventions. Something we are already witnessing in Europe and the US.

For a summery version of the book, read "How global economic growth will drown in Trump's oil glut after 2018"

Economic progress and wealth of society strongly depends on the best choice of energy supply techniques. Like with any living organism, societies needs energy to perform work. Before the industrial revolution we relied on horsepower, wood, wind and human labor. These forms of energy were, however, very inefficient because of their low energy density. It was not until we discovered coal and invented the stream engine that the revolution started and societal metabolism went up. Since then, humanity has been addicted to fossil fuels to propel our societies forward. Now, however, its becoming a real problem because the Earth is not as big as we thought. Fossil fuel extraction and pollution on a massive scale have caused our climate to change and we are running into limits of what the Earth can provide in terms of cheap and abundant natural resources. So we look to alternative technologies for solutions to this predicament. But as we know from the German case this issue is not without its challenges. We need a measurment that that can establish what alternative are most effective in terms of providing a net surplus of energy to society while reducing greenhouse gas emissions. 

Energy return on energy invested

The energy return on (energy) investment (EROI) is an important measure that describes the overall life-cycle efficiency of energy supply techniques, independent of economical and political considerations. The EROI answers the simple question “how much useful (net) energy do we obtain for certain effort to make this energy available” (Weißbach et al. 2013). As we know, energy and matter are never consumed or generated but always just converted. There is always a flow of materials (fuel, materials for construction, maintenance) driven by the “invested” energy with the result of making the “returned” energy available. This means that to calculate net energy of a particular supply technique, also known as carrier, one has to include all the energy it takes to produce electricity - from the extraction of resources to the construction and maintenance of the plant, as well as expected lifetime. Furthermore, because many so called renewable carriers are intermittent they usually require back-up plants or storage that can buffer for when they aren't generating enough electricity at times when people need it. Weißbach et al. 2013 have chosen to include this in their EROI analysis, few others do. Break-even has an EROI of 1. But that would be pointless as you would have a plant but couldn’t run it. The higher the EROI the higher the return on investment.

Energy Money Return on Investment

Because all these carriers produce electricity as output, but not all inputs are electric, the EMROI of all sources is higher than their EROI. This is one step further towards monetizing the EROI by allowing for the greater monetary value of electricity compared to other energy types. We can see that hydro, nuclear, natural gas and solar in the desert have high EMROI. However, EMROI is just a “best case” scenario for monetary return on investment. Note that the economic threshold has gone up to. The idea is that in e.g. the US, a kWh of energy cost about 10 cents but it produces about 70 cents worth of GDP, a ratio of 7 to 1. If we do the same computation in exergy terms, the ratio is 16 to 1. That means the fully monetary return on investment of exergy, for the economy as a whole, is 16. A similar ratio can be seen for other countries which leads to the conclusion that the thresholds are 7 for EROI and 16 for EMROI, assuming OECD-like energy consuming technology. For lower developed countries thresholds might be smaller, thus making also less efficient energies like biomass economic.

By looking at historical development rates of low-CO2 electricity production among different high-income countries we can try to figure out what techniques have worked well previously. Below is a chart showing OECD countries population size and generation of kWh per capita per year.

Overall we can see that only a few countries have succeeded to build low-CO2 electricity production with a rate of 300kWh/cap/year, which is the needed improvement speed to stay below the Kyoto Protocol 2 C degrees limit. One should note that no country have made it above the 300kWh/cap/year without the help of nuclear. We can see that Swedish nuclear development reached the highest level of 700 kWh/cap/year. Mean development rate only reached 120 kWh/cap/year between 1982 and 1992. When it comes to renewable electricity production, Denmark has the highest with about 160 kWh/cap/year. Closely followed by Sweden. Spain and Germany reached levels of 120 kWh/cap/year. We can see that Sweden has a top position in development rate of low-CO2 electricity production, both with nuclear and renewable energy. If the rest of the world would implement nuclear at the same rate as Sweden did, it would take 25 years to replace all existing fossil fuels (Davour et al. 2014). It is very improbable that this will happen, and perhaps isn't recommendable, but the example show how important the inclusion of nuclear into the energy mix is for future low-CO2 electricity production.

Discussion