Biodiesel, Efficiency, and Other Things Which Do Not Matter In The Long Run
This morning matrushkaka asked me if biodiesel is "better for the environment" than regular diesel. The answer is "yes and no".
On one hand, biodiesel is a product of plants recently living on the surface of the earth, not millions-years-dead plant matter formerly deep beneath the earth. Burning biodiesel emits carbon that was already in the biosphere rather than burning carbon formerly sequestered in the ground. If everyone burned biodiesel, biodiesel would save the world from global warming.
But on the other hand everyone won't burn biodiesel because diesel is a fungible commodity. Decreasing your demand for conventional diesel decreases price, encouraging everyone else to burn more conventional diesel. "You haven't discovered an alternative fuel, you've discovered an additional source of carbon emissions. Thanks, hippies!" The net increase will be worse than if you kicked it old school, sending used vegetable oil to a landfill where it stands a chance of being sequestered under tons of nonbiodegradeable garbage.
Driving fuel-efficient cars won't help either, because the first thing you say when you buy a car that's twice as efficient is "now I can drive twice as far for the same price!" You'll still be burning the same amount of gas, you'll just be burning it to drive more miles. If you somehow manage to exercise self-restraint and consume less gas driving the same number of miles demand will drop, price will drop, and someone else will buy your cheap gas and take up your slack. Producing less harmful oxide variants does help without a down-side that I can think of, and a Prius's low emissions are worth commending as long as "low emissions" means "low emissions per gallon of gas burned" rather than "low emissions per mile driven". One way or another someone's going to burn that carbon - what's important is the form that carbon ends up in.
It's still rational and correct to say "by consuming less gas I'm not personally contributing to environmental disaster as much as other people are". Then again it's also rational and correct to say "by consuming less gas I'm lowering gas prices, encouraging other people to contribute to environmental disaster more than I am". "The Titanic's going down either way, but at least it's not my iceberg." Real environmental progress means encouraging everyone to burn fewer hydrocarbons by increasing the price of gas artificially through taxes, naturally through increasing scarcity, or chaotically through mobs of carjackers and French Arab youths. (Although piles of burning cars and factories turning out more cars to replace them are nontrivial environmental factors as well.)
On one hand, biodiesel is a product of plants recently living on the surface of the earth, not millions-years-dead plant matter formerly deep beneath the earth. Burning biodiesel emits carbon that was already in the biosphere rather than burning carbon formerly sequestered in the ground. If everyone burned biodiesel, biodiesel would save the world from global warming.
But on the other hand everyone won't burn biodiesel because diesel is a fungible commodity. Decreasing your demand for conventional diesel decreases price, encouraging everyone else to burn more conventional diesel. "You haven't discovered an alternative fuel, you've discovered an additional source of carbon emissions. Thanks, hippies!" The net increase will be worse than if you kicked it old school, sending used vegetable oil to a landfill where it stands a chance of being sequestered under tons of nonbiodegradeable garbage.
Driving fuel-efficient cars won't help either, because the first thing you say when you buy a car that's twice as efficient is "now I can drive twice as far for the same price!" You'll still be burning the same amount of gas, you'll just be burning it to drive more miles. If you somehow manage to exercise self-restraint and consume less gas driving the same number of miles demand will drop, price will drop, and someone else will buy your cheap gas and take up your slack. Producing less harmful oxide variants does help without a down-side that I can think of, and a Prius's low emissions are worth commending as long as "low emissions" means "low emissions per gallon of gas burned" rather than "low emissions per mile driven". One way or another someone's going to burn that carbon - what's important is the form that carbon ends up in.
It's still rational and correct to say "by consuming less gas I'm not personally contributing to environmental disaster as much as other people are". Then again it's also rational and correct to say "by consuming less gas I'm lowering gas prices, encouraging other people to contribute to environmental disaster more than I am". "The Titanic's going down either way, but at least it's not my iceberg." Real environmental progress means encouraging everyone to burn fewer hydrocarbons by increasing the price of gas artificially through taxes, naturally through increasing scarcity, or chaotically through mobs of carjackers and French Arab youths. (Although piles of burning cars and factories turning out more cars to replace them are nontrivial environmental factors as well.)