Last time around, this combination of circumstances led to a great deal of discussion about biofuels and their potential for replacing oil and gas. So I thought I'd throw some numbers out there, with their verifiable and qualified sources, so that the black-and-white facts of the matter will forestall any irrational exuberance and policy driven by wishful thinking.
(That last bit--kidding. Facts influencing people's behaviour. Ha! Anyway...)
Let's start with what a biofuel-powered world looks like, which is to say, the Middle Ages.
The following table gives an estimate of the total energy consumption of the world in the 11th century AD. (The "MToe" is short for "million tonnes of oil equivalent," as in, the amount of gross heat contained in million tonnes of petroleum.)
| Table 1: Evaluation of global energy consumption in the 11th century (Mtoe/year) | ||
| MToe/year | (%) | |
| Human | 0.38 | 7.2% |
| Man | 0.18 | 3.4% |
| Woman | 0.16 | 3.0% |
| Child | 0.04 | 0.8% |
| Bullock/Animal power | 0.24 | 4.5% |
| Fuelwood | 4.61 | 86.8% |
| Wind and water | 0.08 | 1.5% |
| Total | 5.31 | 100% |
| (%) | 100% | |
| Table adapted from Bashmakov 2007, Bashmakov 2009 | ||
A few things worth noting:
First, the vast majority of that energy (about 87%) was from firewood and most of this was for domestic purposes. Most of the rest was in the form of food consumed by people and draft animals who then did work--tilling fields, smithing iron with hammers, and making the rounds on corpse day. (Remember, plague victims go in the black bin, cans and bottles in the blue one.)
Fast forward to 2008. Gross annual energy consumption worldwide was 11,295 MToe. That's over two thousand times more total energy use than a thousand years ago. Not surprisingly, the vast majority of that energy comes from things other than biofuels and food.
Now, in fairness, there are a lot more people around today--nearly seven billion of us, compared to something like 300 million in the eleventh century. (That's a very rough estimate--about the middle of a range of 245-354 million given in a variety of sources.) There's a whole other conversation to be had about whether we can sustain anything like that population and what it's doing to our ecosystem. But to be fair, if we're going to compare our energy lifestyle to that enjoyed by medieval people, we should look at energy per capita:
| Table 2: World energy, population and energy intensity, 1000 and 2008 AD | |||
| Year | Population | Primary Energy Consumption (Mtoe/year) | Energy per person (kgoe/cap/year) |
| 1000 | 300,000,000 | 5.3 | 17.7 |
| 2008 | 6,749,678,000 | 11,294.9 | 1,673.4 |
| Factor increase | 22.5 | 2,127.1 | 94.5 |
| Data source: BP 2008, OECD 2008, USCB 2009 | |||
So, worlwide, the average person today uses about 95 times as much energy as back in the good old days.
Even that's not a totally fair comparison, though. A lot of people today live in conditions that, frankly, are not all that different from the Bring Out Your Dead guy's. If we're looking to use biofuels to support our current lifestyle or part thereof, we should be comparing per capita energy use in 1000 AD to per capita energy use in the developed world today.
The OECD countries (that is, the developed world) has about one-sixth of the world's population but uses nearly half the energy.
| Table 3: World energy, population and energy intensity: World 1000 vs. OECD 2008 AD | |||
| Year | Population | Primary Energy Consumption (Mtoe/year) | Energy per capita (kgoe/cap/year) |
| World, 1000 | 300,000,000 | 5.3 | 17.7 |
| OECD, 2008 | 1,186,542,000 | 5,508.4 | 4,642.4 |
| Factor increase | 262.3 | ||
| Data source: BP 2009, OECD 2008, USCB 2009 | |||
So our comfortable Western standard of living uses over two hundred and sixty times as much energy as back in the day. Do you really think we can make up more than a tiny fraction of that amount by boosting biomass production?
Sources:
Bashmakov, Igor. Three Laws of Energy Transitions. Energy Policy 35-2007, 3583–3594.
Bashmakov, Igor, Personal communication. August 11, 2009.
British Petroleum. BP Statistical Review of World Energy 2009.
Organization for Economic Cooperation and Development. OECD World Factbook: Economic, Environmental and Social Statistics. 2008.
United States Census Bureau. International Programs. Historical estimates of world population. Accessed October 6, 2009.
No, but we can certainly diversify.
ReplyDeleteConsider what we use energy for: light and heat. If we can find alternate methods of doing same (geothermal, using natural light, solar ovens etc) we can eliminate MUCH of the energy we use.
Biofuels can replace the small amounts of gasoline we'll need after other energy switches. You can't make an electric Harley Davidson, for example. And some people will be taking gasoline powered chainsaws into the woods. The US Department of Energy recently announced an isobutanol conversion from plant mass that's feasible in the amounts we'll need.
We'll eventually also add thorium reactors (once we kill the hippies) and some solar/geothermal/ferret juggling organic carrot muncher options into the mix as well.