Energy is the basis upon which all life exists.
Yet most people take it for granted. Dark? Flip a switch. Need to go somewhere? Hop in a car. Hungry? Open a package of processed energy that came from a thousand kilometers away.
But the energy used in industrialized nations is so far above sustainable levels that it would be laughable, were it not such an imminently serious situation.
Human energy use can be divided up as intrinsic and exosomatic.
Intrinsic energy is released inside our cells by mitochondria from adenosine triphosphate. It is what gives us a body temperature, and what allows muscles to perform work. Modern civilization is so efficient at providing this energy -- through fatty foods and empty calories -- that much of the North American population has health problems related to obesity. Further discussion of intrinsic energy is available in agriculture topics.
Exosomatic energy (literally, "out of body energy") is what gives us all the things we hold dear in our civilization and culture. It supplies our intrinsic energy by bringing food from far away and letting us cook it. It supports health by providing heat for controlling micro organisms and facilities for producing and practicing medicine. It allows us to pursue higher levels of personal meaning (Maslow's hierarchy) by freeing us from the toil of the land.
But this largess is coming to an end. Prior to the widespread use of petroleum, it took five farming families to support one in the city. Today, thousands can live in the city for each person who works on large, factory farms. Agriculture's green revolution is largely due to non-renewable fossil fuels -- for fertilizer, for herbicides and insecticides, and for machinery.
- Prehistoric humans lived on the exosomatic energy equivalent of a single 40 watt light bulb, primarily from burning wood, used for cooking and personal comfort.
- At noon, on the equator, each square meter receives about 1,000 watts of solar energy.
- Current average per capita energy use is about 7,500 watts, 24 hours a day, seven days a week, 365 days a year.
So it's easy to see that each North American consumes the energy equivalent of sunlight falling on an area of about three meters on a side. But the sun doesn't shine 24/7/365, nor do we all live on the equator, so our average energy use is probably closer to four or more times that amount -- a square about six meters on a side.
This is only possible because the earth stored up photosynthetic energy for millions of years. The sun applied it's 1,000 watts to each square meter of vegetation and algae, which used it to split carbon from oxygen to make cellulose for its structure, which then got buried when the living material died, which then was heated under pressure to form coal, oil, and natural gas. Humans have used very nearly half this legacy up, mostly in the past 50 years.
Thanks to this long-term accumulation of solar energy, a 350 horsepower internal combustion engine that fits in about one square meter can consume the equivalent solar energy falling on over 500 square meters! This cannot continue, and will soon go into decline.
- About ten calories of fossil fuel is used to produce each calorie of food energy.
- Driving 5 kilometers to buy a loaf of bread (round trip) in an SUV that consumes 16 liters per 100km uses as much energy as is in that loaf of bread.
- Salt Spring Island produces only about 2% of its own food, and none of its own energy.
What to do?
No one wants to go back to "shivering in the dark" by the heat and light of a single 40W bulb. But neither can we continue to rely on millions of years of stored energy to support our civilization. Yet some things that require a certain excess of energy -- education, health care, technology, art -- have become essential to civilization as we know it.
By lowering our energy needs to 1/8th to 1/4th of today's average level -- about 1,000 to 2,000 watts per person -- we should be able to enjoy most of the important features of modern civilization, but without the excesses. No more pre-made, plastic-bagged caesar salads from southern California, but still a local hospital. No more overnight delivery of a single book from New York, but still a local library. No more cheap plastic crap from China, but still replacement parts for machines used by locals to make useful items. No more "collectible" trinkets from Texas via eBay, but genuine art and craft from local artisans.
This will not be simple, nor easy. Civilization is in the shape its in because humans have taken the simple, easy choices at every turn.
- The first step is awareness. It is so easy to leave a light on, or to hop in the car for a short trip. We must constantly be aware of our energy decisions.
- The next step is reduction. Energy consumption simply cannot continue at its current pace, and much of the developed world is in for "shock and awe" within the next generation -- possibly within the next few years. We must consume less energy while being more efficient using the energy we really need.
- The next step is sustainable energy production. This will be expensive, because energy is heavily subsidized -- both by political processes, and by the geological process that stored up millions of years of sunlight. But using fossil energy is spending down our principle, when we should be living off the interest. We must be creative and resourceful in investing in our energy future.
- The final step is education. Just as the flight attendant tells mothers to secure their own oxygen masks before helping their children, we must save ourselves so that we might save others. We must inform our relatives, friends, associates, and the public at large of the impending energy crisis, and what we all can do about it.
Please see an energy primer for an explanation of physical energy, in layman's terms.
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