Civilization’s Future

We hear that military spending has increased this year. Seems that we spend more and more on fighting. But look at the numbers. Military expenditure is only 2.68% of the value of the world’s gross domestic product. And, much of this goes to maintain a semblance of law and order rather than for inter-national aggression.

The gross domestic product is a sound marker for the amount of energy that humans use. So, we can estimate that 2.68% of the energy goes to defence. And using published figures then 4.8% goes to education and 6.2% to health care. Yet, adding these altogether leaves 86.3% of the energy undefined.

In 2008, humans consumed 4.74e20 Joules of primary energy. How did we use the 86.3% of this? That’s 4.1e20 Joules for which we have no account.

The trophic pyramid graphically demonstrates how a few number and variety of complex species rely upon a vast number of much simpler species. For example, a hawk soars over the countryside, peering across vast distances for the slightest motion perhaps of a scurrying mouse. The mouse remains close to its nest, occasionally making a dash for nearby seeds. The plants that produce the seed don’t move but simply grow and hopefully expand their territory by casting seeds about. Without the grass, the mouse and hawk disappear. What happens without the mouse and hawk?

The Census of Marine Life estimates that there are 80 to 90 percent fewer fish and marine mammals in the ocean than from 2000 years ago. People have effectively consumed the top of the ocean’s trophic pyramid. Now, species at the lower levels live longer lives. But, any service provided by the predators, such as thinning out the weak and old, no longer occurs. Further, the energy and nutrients within the species’ body no longer climbs up the trophic pyramid to the avail of complex species like humans.

The radical alteration in oceanic life parallels the changes occurring on land. Natural selection no longer prevails in evolution. Abundant energy sources like vast fields of grain no longer provide a niche for an evolving species. Everything is focused upon the sustenance of humankind. Where will this evolution take us and our civilization?

We consume energy in some very innocuous ways. Typical daily hygiene requires us to brush our teeth 2 to 3 times each day. Our tool for this is a plastic toothbrush with nylon bristles. Plastic is a petroleum by-product. Petroleum, as we all know, is our choice energy source for over a third of our primary energy sources.

A toothbrush consists of about 12 grams of plastic. Plastic has an energy density of about 46 Joules per gram. People of the United States use about 459 million brushes every year. So, this country deposits 2.53e11 Joules annually for toothbrushes. The first modern, nylon toothbrush was made in 1938. Thus, we can estimate that they’ve allocated nearly 1.7e13 Joules for clean teeth since then.

At one time, toothbrushes were made of wood. Wood has an energy content of about 20 MJ/kilogram. Assume that the energy density is similar to plastic. Then, to replace plastic, they’d need 12 000 kilograms of wood every year. That’s a lot of trees.

Imagine you’re driving along on a busy, wide road. There’s four lanes, two lanes going in your direction and two going away. Up ahead red traffic lights shine, signalling everyone to stop.

You can save energy by coasting up to the stop line. But, if you do so then you’ll be passed by a large number of cars that aren’t coasting. This means that they will be ahead and closer to their destination. This may be a good or bad thing as only time can tell.

On the other hand, you can speed up, prevent any cars from passing you or getting close to you. But, if you do so then you’ll have to stop very quickly or you might have an accident. At least temporarily, other cars remain behind.

Being an individual empowers you to make any choice and hopefully you’ll assess the consequences before doing so. Do nations have the same choice and the citizens consider the consequences. How should our civilization allocate the remaining stores of non-renewable energy?