Energy Efficiency
One of the best ways people can reduce their carbon footprint is also one of the most simple. All you need to do is replace the light bulbs in your home with CFLs (compact florescent's). They use 66 percent less energy, and last up to 10 times longer then regular incandescents, which ultimately means you will save money when you make the switch. Other ways to be efficient with energy in the home include sealing all air gaps with silicone, adding insulation into the attic and walls, and turning off the heater/AC at night and when you leave. Be sure to buy new products with a green mind as well. Energy-efficient appliances, and high MPG economy cars can have a huge impact.
Plant a Tree
Even if you don't own your own home, there are still plenty of places you can plant a tree. Ask your city counsel about tree planting programs in your neighborhood. Trees combat the effects of global warming by absorbing greenhouse gasses and releasing oxygen. The major forests around the world are shrinking drastically every day, so we need all the trees possible to offset those losses.
Install Solar Panels
If you live in a sun-rich area, solar panels are a great way to reduce your carbon footprint. Although they can be expensive at first, there are many government rebate programs that will give you up to a $10,000 credit after you install them! Many times home owners will find that their electricity meters will barely move after they've installed panels.
Reuse and Recycle
Start to use rechargeable batteries in your house instead of disposable. Use an electronic razor instead of a throw-away. Try to avoid paper cups and plates. There are many items that have a long life, and if you choose them instead of one-time-use products, you cut manufacturing and processing down significantly. Also make a habit of recycling anything and everything that you can. Glass, aluminum, paper and plastic take a sizable amount of energy to create from scratch. When we reuse raw materials we expend less energy.