Monday, April 13, 2009 - 16:14
Is transportation really becoming “greener”?
After all, there are so many more “green” cars today than before. Hybrids are becoming increasingly common, and work is constantly being done by car manufacturers to improve gas mileage and create alternatively powered cars. Car companies are pouring dollars into research to create cars that will “go the extra mile”.
No doubt, hybrid cars are better than gas-powered cars. Generally, a hybrid can cut emissions by 25 percent to 35 percent over even the most fuel-efficient gas-powered models, according to physorg.com. Hybrids reduce the amount of carbon dioxide from going into the atmosphere — and every little bit helps. However, it is only a very little bit, after all. The vast majority of the cars today are not hybrids. And even if more people start switching to more fuel-efficient cars, other car drivers will still be leaving a heavy impact on the earth.
Hybrids aside, it is easy to think transportation is becoming “cleaner”. You’ve probably seen older cars chugging along the road spewing black smoke. Gasoline, which powers the cars’ engines, is made up mostly of a mixture of hydrocarbons, molecules made of hydrogen and carbon. Ideally, hydrocarbons combine with pure oxygen to form carbon dioxide and water. Yet impurities and contaminants cause this reaction to happen imperfectly in car engines, especially in older engines. Gasoline is not ALL pure hydrocarbons (ever seen the “minimum octane rating”? That tells you how much octane — a hydrocarbon — is there in that particular gasoline; the more the octane rating, the more “complete” the reaction will be). Most of the gasoline reacts with the oxygen in air, and most of it turns into carbon dioxide and water — yet even this reaction is not complete. Some of it turns to regular carbon, instead of carbon dioxide. That carbon is what makes the smoke from the cars’ exhausts black.
Secondly, the hydrocarbons do not burn in the presence of "pure" oxygen — cars don’t have pure oxygen tanks! They actually burn in the presence of regular air, which contains a mixture of oxygen AND other gases. The most common gas in the air is nitrogen. Therefore, some of the gasoline in the older cars reacts with the nitrogen to produce nitrogen dioxide — the most toxic gas from burning gasoline. Fortunately, science and chemistry allowed for advances in engine design that later converted the nitrogen dioxide to nitrogen and oxygen ... harmless gases -- all thanks to the use of sophisticated catalysts to make this happen. (Some complex chemistry here.)
We have gotten rid of the toxic nitrogen dioxide problem. We have figured out how to create a more complete reaction of the hydrocarbons to significantly lessen pollution. Thanks to science, today’s cars don’t spew noxious black smoke. But the invisible gas that even the most fuel-efficient cars do spew is now turning out to be as bad — if not worse — than the black smoke and noxious gases of older cars: carbon dioxide.
What is the solution to the carbon dioxide problem? The basic problem of transportation in the United States and several other countries is that car companies are investing more and more money into developing more energy-efficient cars. Yet, after all, we are still running on a car per person basis, and the emissions from that can certainly be reduced considerably.
If the money that is being poured into fuel efficiency for single cars was used to create more accessible and better public transportation, the emissions would be cut down much more. Biking and walking -- certainly the most earth-friendly ways of transportation -- might not be feasible for everyone all the time. But the potentials for public transportation are many -- after all, what can’t public transport offer that single cars can? Public transport needs to turn from a means of transport for a few to the means of transport for many. That’s green transportation!
You might also like: