As a scientist, I tend to think that the right technology can make any problem moot ("with the right sustainable, clean energy source, none of this would matter..."). However, after reading a bit about the Jevons paradox, I think my previous assumptions might be a little polyannaish. The Jevons paradox isn't really a paradox, per se, but rather an observation made by an economist about the relationship between technology and consumption. Jevons noted that if a technology were to make a process like energy production more efficient, this effectively decreases its cost, which can result overall in an increased demand, despite needing less energy for any one purpose. From Wikipedia:

In his 1865 book The Coal Question, Jevons observed that England's consumption of coal soared after James Watt introduced his coal-fired steam engine, which greatly improved the efficiency of Thomas Newcomen's earlier design. Watt's innovations made coal a more cost effective power source, leading to increased use of his steam engine in a wide range of industries. This in turn made total coal consumption rise, even as the amount of coal required for any particular application fell.

It's quite likely that by decreasing the real cost of energy, one could actually inflate the world's appetite for energy. This would suggest that in the absence of an abundant source of sustainable energy, the only real solution is conservation. One of the most effective ways to conserve is to live in a place that doesn't require so much damned transportation and environmental conditioning, if at all possible.

I am lucky to live in a place that doesn't require me to commute long distances every day; I can brag that I drive less than 150 miles each month. This means I spend, on average, only $35 a month on gas. This is due, in part, to the planning of cities like Berkeley. Pre-war towns like this one never envisioned each citizen lugging one ton of steel 15 miles to the grocery store; likewise most restaurants are placed within walking distance on the older parts of town. It's not that Berkeley is a dense urban metropolis like New York City (I have a big backyard), it's more that the people who live here are forced to live within the spatial and energy constraints of urban life before the automobile (and trust me, life is so much better that way!). It also helps that we have a robust public transportation system.

In addition, we are situated not too far from the breadbasket of California, the central valley. So we're pretty close to farm produce, and we don't need it trucked in from, say, Texas. We also have good local supplies of potable water. I don't mean to say that northern California is the only good place to live, it's just that it actually makes sense for human beings to live here: we don't need air conditioning, a car, fleets of diesel trucks delivering goods from out-of-state... we pretty much have it here, and it doesn't take ever increasing amounts of energy to live comfortably in a place like this.

You may not be able to change your city, but there are several choices you can make on a daily basis that will help ease this global problem regardless of where you live. Importing agricultural products from out-of-state is an incredibly wasteful process, and one that can be avoided if you live in a state with a local agriculture industry. You can actually make a big difference in the world's energy supply by simply choosing which foods to eat:

• Eat locally grown fruits and vegetables (this can often mean choosing to shop only at grocery stores that tell you where the produce is grown);
• Learn which vegetables are seasonal, and cook with seasonal foods (i.e. during the winter, avoid fruits and veggies that require shipment from South America, like tomatoes); and
• Avoid mass-market chain restaurants whose food is often grown in one state, shipped to another for pre-processing, then again transported to your home state all before you eat it.

You can read more about choosing local foods here, here, and here. Your everyday choices really can make a big difference.

UPDATE: More thoughts here.