Sustaining a Population

What is the Minimum EROI [Energy Return on Investment] that a Sustainable Society Must Have?

by Charles A. S. Hall, Stephen Balogh and David J. R. Murphy
Program in Environmental Science, State University of New York – College of Environmental Science and Forestry, Syracuse NY, 13210, USA

…Every plant and every animal must conform to this iron “law” of evolutionary energetics: if you are to survive you must produce or capture more energy than you use to obtain it, if you are to reproduce you must have a large surplus beyond metabolic needs, and if your species are to prosper over evolutionary time you must have a very large surplus for the average individual to compensate for the large losses that occur to the majority of the population. In other words every surviving individual and species needs to do things that gain more energy than they cost, and those species that are successful in an evolutionary sense are those that generate a great deal of surplus energy that allows them to become abundant and to spread. While we are unaware of any official pronouncement of this idea as a law, it seems to us to be so self-obvious that we might as well call it a law – the law of minimum EROI – unless anyone can think of any objections.Read the rest of the article here

A mother cheetah must chase and catch a gazelle or rabbit and obtain enough energy from it not only to feed her kids, but also to be able to chase another one down and even survive some days without catching anything.

Hawaiians understood this concept very clearly. It’s why in the Hawaiian culture there is such a close affinity to the land, the ocean and all things in nature: That is where the surplus energy came from to sustain the population.

The move to populate Hawai‘i probably came from a need to find surplus energy (food) caused by overpopulation or similar in the navigating Polynesians’ home islands.

We all know there are clouds on the horizon now, and that our surplus energy supplies are again threatened.

In the 1930s, it took one barrel of oil to obtain 100 barrels. In the 70s, that ratio had decreased to 1 to 30. A few years ago, it was estimated to be 1 to a little more than 10.

When it finally dawns on all of us that our oil supplies will never increase, people will get frightened. But at that point, it will be too late.

Most of us Hawaiians look upon our geothermal resource as a gift. And even more so now, when it can be a matter of survival of the species.

We’ve done it before and we need to do it again. Pau talk, ‘nough planning. We go!