Global warming is a big issue these days, but nobody has practical advice that you and I can follow to try and alleviate the problem. The root cause of global warming can be identified as the resources we use. In other words the more we buy, more factories are run, more transportation is used, more people have to commute, etc thus adding to the carbon dioxide content in the atmosphere. So the simple advice to people who want to do something towards the problem is to buy less.
However, since I buy a lot and do not follow this advice, it's not fair on my part to give this advice. So the following are some of the things I have been able to follow to do my part towards reducing my carbon footprint.
1) Have a house near your work place / University - If you are renting a house, then this is easy. Move to a place near where you work. Ideally you should be able to walk to the work place. My university is at a 20 minute walk from home, thus making a car unnecessary for the daily commute (though I do have a car).
Other benefits: Save money, get a bit of exercise.
2) Eat raw food whenever possible - One of my daily meals, the dinner, consists solely of raw fruits and a glass of orange juice. Nothing processed or cooked, thus saving the energy necessary.
Other benefits: Saves the need to cook for one meal, healthy.
3) Cook for several days at once - Since I cook Indian food, I cook a dish once every four days and make rice once for two days. This saves the electricity needed to cook.
Other benefits: Save time, healthy, save money since you have cooked and don't have to eat out.
4) Shave less (if possible) - Shave once in two days instead of everyday. Saves the shaving cream, razor, after shave, etc associated with shaving.
Other benefits: Save money.
5) Obvious - switch off TV, lights, etc when you get out of your room, even if only for a few minutes minutes.
Other benefits: Save money on electricity bills.
6) Use cold water to brush teeth, wash hands, wash dishes, etc - saves the energy required to heat up the water.
Other benefits: Save money on gas bills.
7) Use air conditioning in your car sparingly, only if absolutely necessary - Air conditioners in cars reduce the mileage of the car. Especially in a country like the UK, when it is almost always cool, use AC sparingly. Open the window if necessary.
Other benefits: Save money on petrol.
8) Sleep early, wake up early - By sleeping early, you switch off all the lights, TV, electrical items, etc saving on your electricity usage.
Other benefits: Save money on electricity.
9) Turn off the heater (or turn it down at night) - In the night, when you are sleeping, you are generally under a good quilt and are warm under it. Turning the heater off or down will save on the gas usage.
The above are a few simple things I have been able to follow for an extended period of time. I believe that if everyone does their bit in simple ways, it is possible to save the environment.