Before we begin though, let’s first try and nail down what we mean by alternative fuels. I’m going to narrow it down to technologies that either supplement or completely replace the petroleum-based internal combustion engine. So ethanol is out. Which is fine. Plenty of other people have already addressed the many problems of bio-fuels in general and ethanol in particular. Hell, even Glenn Beck hates it. It’s probably the one thing he agrees with Al Gore on.
Currently the most popular alternative is hybrid vehicles, of which the Toyota Prius is the best known. To date, about 2 million hybrid vehicles have been sold in the United States. These run on gas part of the time and on an electric battery part of the time. So in the end this actually does almost nothing to replace petroleum based fuels, it simply reduces consumption levels. You get better mileage and therefor use less gas, though the difference is usually not as dramatic as you might think. Hybrids are much better than guzzlers to be sure, but barely competitive with the MPG rating of the most efficient diesel engines. You also pollute less because there’s no emission when you’re running on the battery, but again, you’re not eliminating emissions, just reducing them.
Cars that run on a battery full-time are just making their way to the market now. Or more accurately, back to the market. Five years ago, the film Who Killed The Electric Car documented the ill-fated first go-around of plug-ins. Take two. This time, the Nissan Leaf and Chevy Volt are leading the way in the U.S.
Plug-ins have great mileage, they’re quiet, and have no direct emissions. Right now, however, they’re quite expensive. 
The Volt is over $43,000. The Leaf is substantially cheaper, but still starts at almost $33,000. And just because the there’s no tailpipe belching exhaust doesn’t mean plug-ins are carbon-free. After all, the great bulk of electricity in this country comes from fossil fuel-burning plants. So while plug-ins are a great improvement, they don’t actually solve the problem.
Cars fueled by hydrogen come in two varieties: those that burn the hydrogen, much like a traditional internal combustion engine, and those that turn it into electricity. The latter is more fuel efficient. In either case, however, the hydrogen combines with oxygen to produce an emission we can all live with: water. Hydrogen cars are still in the prototype phase. There are issues with storing of the heavy and highly flammable hydrogen. It may come to pass, it may not.
But for argument’s sake, let’s say that one day relatively soon researchers and businesses are able to offer an affordable, safe, emission-free car that runs on hydrogen, some other fuel like oxyhydrogen or liquified nitrogen, or even something wonderfully simple like steam or solar. Would that be a vast improvement? Yes. But would there still be serious problems associated with cars? Absolutely.
The problems with cars run very deep. The exacerbation of global warming through greenhouse emissions cause by today’s cars are an obvious problem that needs to be addressed immediately. But it’s hardly the only issue.
In the last article, I mentioned the roughly 30,000 people who die every year in car crashes. Cars are inherently dangerous no matter what they run on. Two tons of steel flying down the highway at 70 miles per hour, not to mention 
moving through areas with pedestrians at any speed will continue to result in thousands of fatalities. When he taught me to drive, my father said to never forget that whenever you get behind the wheel, you’re getting into a killing machine. He was right.
But there’s a more abstract type of damage that cars do not only to individuals, but to our larger society. They are terribly isolating. At times that can be a pleasurable sensation. But in general it contributes to the ongoing alienation of people from each other. Unlike walking, riding side by side on horseback, or sharing mass transit, cars lock us away from everyone else, and the damage is real.
Road rage in one symptom of that isolation, that alienation. People behaving in ways they otherwise never would because they change once they’re in that little bubble. Yet it goes deeper than that.
We are social creatures by nature, as Aristotle once noted. And cars are a tremendously anti-social technology, making strangers of us all.