Two big purchases cause most of your environmental impact – your house and your car. The environmental footprint of these two big items merge when you think about location: Is your house located where you can conveniently bike for some of your trips?
A car is 3,000 pounds or more. (We will try not to even consider those 6,000+ pound SUVs). So, if you need to get a pint of milk, it is pretty inefficient to move yourself, plus a 3,000 pound metal car, a long ways to get 16 oz. of milk.
Going to work may be your most frequent trip. If you live close to work, with relatively safe streets for biking, biking to work can be a refreshing, environmentally sound way to avoid unnecessarily burning oil to move a 3,000-pound piece of metal. However, keep in mind that it is not worth (in my opinion) biking near fast traffic. The death rate for car-bike collisions goes up very sharply as traffic speed rises above 25, 35, and 40 miles per hour. Many avid bikers will disagree with me here, so it is a matter of preference.
A fancy bike is not needed. If you need to carry stuff, get a mountain bike (or touring bike) and attach a rack and panniers to carry lunch, laptop or papers. You can make your own waterproof panniers out of kitty litter buckets, using conduit hanger and screws to secure them to the bike’s rack. (There are DIY plans all over the internet that use bungee-cords; do yourself a favor and use metal hardware, so they don’t pop off unexpectedly.)
If you can travel light, a road bike gives you more speed and range. From about 2000 to 2006, Giant made road bikes (the OCR line) that also accept racks and panniers, giving you the best of both worlds. Old touring bikes (look like road bikes) also have attachment points for panniers.
Yes, it is 100 degrees during the summer in Arkansas. So, if you don’t live very close to work, you can wait for fall (but buy an LED headlight so that you are lit coming home). We live on a landscape built for cars; but with common sense, and the right location, you can enjoy a bike ride to work at least some of the year.