I want to make this clear to folks: We cannot drive our way out of this crisis. No wundercar is coming. None of the technologies listed above, or any others that I am aware of, will come to fruition quickly enough to transform our transportation system in time to make a difference in our climate footprint. Experts agree that we need to make drastic changes over the next decade, to reduce our C02 emissions to below 1990 levels and be well on the way down from there, by 2020. Without a government program the size of which this world has never seen, none of these technologies will have an adequate distribution network, nor will a large enough proportion of our fleet switch over to them quickly enough to make this sort of change. And as far as massive government programs, the political will simply doesn't exist. A substantial portion of our country doesn't even believe in climate change. Now, look at what it took to pass even the meager health care reforms that got through our Congress last year- and remember that we all universally believe disease exists.
Even if we were to manage to switch to any one of these technologies, they all have their faults:
- Electric cars: Not only would you have to get people to buy them and build an infrastructure that allowed for quick charging (because part of having cars is going road-tripping), but you would also have to get clean, green power to charge them up. Right now, most power in the US is still fossil-fueled (coal on the east coast, LNG on the west), with an appreciable dent made by large hydropower in the Pacific Northwest. Add to this a national energy grid able to handle the stress of providing all of our automotive energy needs when it currently struggles to run our air conditioners. While I think that we need to do most of these grid-related things anyway, we wouldn't need to build nearly as many windmills and solar panels if we didn't have to worry about charging electric cars as well.
- Hybrids: Fossil fuels cannot make up a significant portion of our transportation energy mix. We all know the problems they cause. Current hybrids are simply fossil-fueled cars with a more efficient drive train. The 2010 Prius gets an EPA-estimated 50MPG, which is a significant improvement over a fleet that currently averages around 18, but this still isn't a high enough bar to avert serious environmental catastrophe over the next few decades.
Besides all of this, in some ways the environmental footprint of a hybrid is greater than that of a comparable gasoline-driven model. The massive batteries involved in hybrid drive demand large quantities of heavy metals that take significant resources to extract and transport.
Don't get me wrong, if you have to buy a car right now, by all means get a hybrid- and drive it as little as possible.
- Plug-in Hybrids: Manage to combine all the polluting and manufacturing-related troubles of a normal hybrid with the energy grid troubles of pure-electric cars.
- Hydrogen vehicles: Despite the fact that hydrogen is the single most abundant element in the universe, it has the unpleasant tendency of becoming easily chemically bound up in other compounds here on Earth. Most industrial hydrogen production today is actually done through reforming- you guessed it- fossil fuels. ('Nuff said.) The greenest way to produce elemental hydrogen is the electrolysis of water, which uses electricity to separate the bonds between water's hydrogen and oxygen molecules. The trouble, though, is that (consistent with the 2nd Law of Thermodynamics) you don't get more energy out than you put in. Therefore, hydrogen fuel is not actually a fuel per se, but an energy storage method, like a chemical battery. And, as a battery, it's not a very efficient one. So, since hydrogen is about producing electricity, it has all the energy grid troubles of electric cars- and then troubles involved in storing, transporting and selling hydrogen fuel. These aren't insurmountable, but they're more difficult than gasoline. Oh, and because it's rather inefficient (compared to modern batteries), we need even more green electricity.
- Air cars: Similar to hydrogen, compressed-air cars are simply a way of storing energy produced via an electric (probably) compressor and releasing it in a car. The main issue with this is that, to get any appreciable range out of a car, you have to store very, very high-pressure air, and so the containment vessel required increases in complexity. If you've ever seen the Mythbusters playing around with compressed air (and chickens, or perhaps the creamer cannon of doom), you know that, if compressed air is released rapidly, it does so with explosive consequences. Contrary to what you've learned in the movies, gasoline usually doesn't explode during collisions. Imagine a compressed air tank exploding during a collision.
All of these are technical and political problems, and they could, theoretically, be worked out. I highly doubt it, and would rather not bet the future of the human race on it, but it's possible. However, even if we were to devise a perfect car, one made out of recycled tires and printer paper, one that harnesses photosynthesis to not only be carbon-neutral, but actually make energy from atmospheric C02, even if we could make a car with no direct environmental impact, it would still be an environmental and social disaster. Our waterways are contaminated by engine fluids and lubricants that run off of road surfaces. Our natural groundwater tables are falling because rainwater is unable to penetrate pavement. Cars still allow sprawling development that eats up wild lands and spits out bland suburbia. Species' ranges in the few precious areas of wilderness that we have are disrupted by highways. We would still live in a society where we shut ourselves off from one another in our own private boxes, promoting inequality and a lack of respect for shared humanity. We would still leave our inner cities to dangle. Our streets would still be unsafe places for children to play, and we would still kill thousands every year in automobile crashes. Alternative fuels are, on a perfect day, a solution to only a few of the myriad problems that cars cause.
On the other hand, instead of pursuing unproven technologies in a desperate last-ditch attempt to hang on to the way of life we've been living for the last 50 or so years, why don't we look ahead and try to build a better world. The technology behind transit vehicles- buses, trolleybuses, and electric streetcars and trains- is well-tested and easily implemented, and is more suited to renewable energy than the mass implementation of electric vehicles. The bicycle has remained in more-or-less its present form for most of the last century, and that is because it works delightfully well. Not to mention that man has been walking upright for several million years. A growing fraction of the American public has expressed a desire to live in denser, more walkable neighbourhoods with more transportation choices. As it stands today, these people are a minority, but a large one (~35-40%), and they are a majority of my generation. Numerous analyses have shown that urban living is safer and healthier than suburbs. Our downtowns are ripe for redevelopment and reinvestment. Instead of a risky gamble to maintain a failing lifestyle, we should spend our resources on forging a bright future based around principles of city-building as old as cities themselves.
(It seems that this post has been featured on Streetsblog. Welcome, Streetsbloggers, and thanks for this honour.)