If you're concerned about what Schwinn is doing to the planet in the process of building you a shiny new cruiser, build one yourself. Lots of cities have terrific recycle-a-bike programs to help you get started. Here in Memphis, for instance, we've got a shop that will hook you up with all the pieces you need - used, of course - as well as some real nice shop space and quality instruction for just 40 bucks. Zero impact. Learn how to build a bike. Meet some new friends. Can't beat it.

Please remove the GM propaganda from your site. "Green by Design", that's a laugh. Norway is banning green claims in car ads unless they can prove it, which is really not possible.

I think it is important to consider the larger picture in addition to merely the arithmetic of greenhouse gases.  The major area that comes to mind is the health benefit and the concomitant savings to our national health care costs whenever we increase our physical activity.  Secondly, one gets to really know the neighborhood, your own or the one you are visiting.  Aesthetically, biking is far superior to riding a car or public transportation, and if you bring your camera, you can take some wonderful shots home.

Get out there!

recently read that an average car uses the equivalent of over 1800 calories per mile driven and an average bike uses 35. the article further stated that walking uses more calories than biking. bikes rate as one of the pro-eco wonders of the world!
i have a small fold-up electric trike. it weighs almost 50# and moves at about 18mph. it carries me and a few bags of groceries and has cut my car usage drastically. if it is less than a mile, i walk. if more, i bike. the car is now used an average of 75 miles a month. :-D emmer

    The new lean mean parker, having used up more energy and body mass driving his bike, will also lower his carbon footprint by using less energy to be cremated. Composting is an option as well, but the details are fuzzy.

There are so many unwanted bikes out there that used bikes have very little value in the US. If you can't score an almost-like-new bike to meet your needs at a garage sale for about $20, then I guess you need a bike to get to the sales... or try Craigslist or Freecycle (no pun inten...!).

In terms of energy efficiency, the comparision of a 30-50 lb pedal driven machine vs. a 2 ton gasoline driven one is hardly worth doing the math. (Kudos to you, Umbra!) You could fill your garage up with bike parts, eat pounds of meat a day (ugh), and steal lollipops from schoolkids and still come out ahead of commuting by car.

Myself, I'm saving my pennies for a cargo trike so that I can sell my car and cancel my gym membership for good!

70% of the worlds bikes are made in China and another 15% made in India, that # per $1000 is skewed. The average wage for 85% of the worlds bikes is less than 50 cents an hour. The average wage for car production globally is well over $50/hour when beni's are added in. Thats a factor of 100 that is not being added in here due to wage disparity. Add in that about 100 million bikes get made each year compared to 70 illion cars the manufacturing cleanliness is not a slam dunk that everyone seems to think it is.

Granted the jist is the same, cars are way more harmful based on there intended use. The bigger issue is how bikes are made and how people that make them are treated. There are a few bike companies trying to address this very issue (Dahon, Kind Bicycles) but it is a long road.

If you increase the ammount of plant foods you eat rather that meats, you'll still be using less reasources than you did when you ate less food.  "Growing" meat is much more reasource intensive than growing plants, so, the vegans are right in that respect.  Plant based diets have a smaller carbon footprint. (though, I think forgoing honey and yeast is just a little silly.)

Drunk drivers kill people in cars or on bicycles. As bicycling becomes more popular, people will review the road rules and sober accidents will be avoided. Very much like trying to find statistics on the number of Amish buggies hit per year.

In addition to the advice above about buying a used bike or rehabilitating one, which I heartily endorse-- I offer my own additional personal daily practice:

While I am out and about riding to work or whatever, I pick up at least 10 pieces of trash per day. I focus on the non-biodegradable items, and try to recycle as much of it as I can.   I know where the trash cans and recycle bins are along my daily commute route, and have agitated for more recycle bins in the lobby at my office.  Most of the time I don't stop at 10 items... it is very empowering knowing I am making a difference each day, even if I don't pick up every single piece of trash I see.  People in the neighborhoods have noticed and offered their thanks for what I am doing.  I tell them, "You can do it, too!"
Usually I end up with about 6-12 plastic beverage bottles and 3-10 aluminum cans on my 5 mile ride through town.  

I put them in a plastic grocery bag, of which I usually carry a couple stuffed underneath my bike seat.  The bags double as a seat cover if it is rainy out where I park the bike.  I've noticed that the grocery bags are constantly blowing off of the local store parking lot... many get trapped in the fence by the edge of the lot, and others are hung up in the vegetation alongside the river where my bike trail passes it.   I catch them before they get into the waterway which empties into the ocean where the plastic bag graveyards float at the midocean gyres...

Bonus: aluminum cans recycled save 95 percent of the energy required to make a new one.  Bikes are made up largely of aluminum these days...   Thus, it is entirely feasible to ZERO OUT out the carbon footprint of one's bicycle's manufacture by picking up and recycling aluminum cans and plastic or glass solid waste litter.

In addition, this reduces water pollution since trash in the curb gutter usually is washed into the storm drains which feed to creeks and rivers every time it rains.

I say: try it, and the health benefits of cycling will combine with the psychological benefits of visibly helping the planet-- and take your environmental commitment to the next level!  If enough of us adopt this empowering approach, pretty soon most of our toughest problems (which seem to demand local solutions to be effective) will be solved.

I am confused that someone would be worried about the environmental impact of biking! Next to walking this is the cleanest mode of transportation I can think of! Is there anything that doesn't affect the environment in some way?

I also disagree with the implication (in Umbra's answer) that veggie eaters are somehow more environmentally friendly than meat eaters. This is simply not true. Vegetables need to be planted and harvested with machinery (for bulk farms), some farms use manufactured piping for irrigation, and there is also the problem of pesticides and fertilizers--not all farms are organic. So there really is NO food, or transportation,  source that is 100% environmentally friendly!

So what do we do? Should we all go naked, walk to work (and everywhere else), and only eat grass and roots? Because that's the only way that I can see to achieve a "zero" carbon footprint.

This is an imperfect world, there is only so much we can do! It is like a "limit line", you can get close to zero, but you can never actually achieve it.  

As a regular bike commuter, I have always been curious about the carbon footprint and overall damage caused by my (used) two-wheeled wonder, but in the long term, I am happy with my choice to be another cyclist out on the road.  In my opinion, increased bike ridership has far more significant benefits for long term land use/transportation planning, urban air quality, and community health than a car or public bus.  

Disappointingly for guilty-conscience drivers (and equally disappointingly for my personal fitness goals!), bicycling is so incredibly energy efficient that it really doesn't burn that many calories. When I bike to work (and back!), I burn an extra 155 calories of food compared to what I'd burn taking the train. That gives me license to eat enough Ben & Jerry's ice cream to fill... a shot glass. Bummer.

Even a heavy bicycle weighs less than just the (poisonous) raw nickel in a Prius' battery pack. You won't get a lot of mileage, so to speak, out of bicycle manufacturing's environmental footprint. The act of bicycling produces zero toxic waste, quite unlike driving (which is largely responsible for urban air pollution and a major source of urban water pollution).

Traveler writes of "the major area that comes to mind" -- for me, it's, well, the area of a car. One car driving in town requires as much road space as 30 bicyclists. Not only is that road space very valuable (and expensive to build and maintain), but all that extra pavement has immense ecological and social costs.

Another major difference: cars don't just kill people indirectly, through pollution or obesity; they kill people directly, too. Cars kill more Americans than guns do, whereas beds kill more Americans than bicycles do.

@ ajazzfan

First off, growing vegetables requires much less energy than growing meat.  If you want to talk about the way its done now, you could look at it this way:

To grow your typical cow, first you gotta grow several fields of corn and/or other grains.  then you gotta keep regrowing all those fields cause the cow will eat it.  And since the cow it eating it, the cow will be pooping, so you gotta figure out a way to get rid of that (or you could just leave it there and let the cow stand its own poop they way a lot of feedlots like to do).  So you're taking a whole bunch of grain products, feeding them to a cow, and getting a relatively small amount of meat for the use of your grain.

And it pretty much works that way for whatever sort of farm grown meat you're getting.

So, it's much less energy intensive to just go ahead and eat the grain (or other vegetable) as is.

Of course, it's a whole different matter if you're talking about growing cows the old-fashioned way: letting them wander around eating grass.  But then you have take things like over-grazing and erosion into account.  You also have to consider than beef would be much more expensive and not nearly so common if they did it the old fashioned way, because there's simply not enough room to let the number of animals we have cramped into feedlots wander around being real cows.

Once again, the same goes for pigs and chickens and such.

There is enough land in the world to provide everyone who's here now with a good diet... made of vegetables. (and assuming the food and land was distributed equitably and such).  But there isn't enough to feed everyone the kind of diet that cow eating people in America seem to think is their god given right.

And let's face it, cows just don't taste that good. Moooo