Gardening was already mentioned. Great idea. Shop your local farmers’ markets for fresh, better, sometimes organic, cheaper food. There are two things about this–local farmers/gardeners probably use fewer chemicals on their crops than industrial farms. Second, it takes a lot less fuel (carbon emissions) to get the food a few miles to town than it does to transport it across the country, or from another country.

Find ways to reuse everyday items. For example, Ziploc bags. Turn them inside out and wash them. Let them air dry and reuse (never if they’ve had raw meat in them). Wash and reuse margarine containers, etc instead of throwing them out. Find a store that will fill gallon water jugs. Our Wal-Mart has a machine that’s 33 cents a gallon–that’s half the price of a new gallon of drinking water. Then, reuse your 20 ounce water bottles by filling them with this water, instead of throwing them out.

Dry your laundry outside on the line rather than running the dryer. Saves energy and money. Look for a homemade laundry soap recipe on the ‘net. Lots out there. They are more natural and only cost a penny a load or something.

Do you take part in household cleaning? If so, vinegar or baking soda will clean just about anything. Much easier on the environment and cheaper than commercial cleaners, too.

Do you do any cooking for your family? Try vegetarian meals. As I’m sure you know, it takes a lot of food resources to produce meat.

Buy used. It saves using up the resources and energy of making new products. Also, keeps us from supporting overseas sweat shops. I love thrift stores and rummage sales for used clothing. Obviously, way less expensive.

Normal things–take shorter showers, turn of lights and appliances when not in use, turn the water off when you brush your teeth, turn the thermostat up a couple degrees and dress cooler (or vice versa, depending on the climate/season).

How about recycling? Do you guys do it? If not, find out how it works in your community. In our town, they give you a recycling bin (as many as you want, actually) for free and pick it up once a month. Would they be okay with it, if it’s free?

Show them how some of the things also save money. Are they going to run right out and pay an extra dollar for Organic Grape Nuts? Probably not. My best advice if you want to eat the organic food that’s packaged and you can buy in a store is to get a little part time job and buy the things for yourself. Money’s tight for everyone right now.

I’ve dealt with a generation gap on issues like this before. I’m in my 30’s and my dad’s a farmer. He just totally shuts me out when I start talking about "organic" or "GMO’s" or "environment". So I know what you’re going through and from my experience, it’s impossible to change their minds. You can only do what you can do. Good luck.

edit–the guy below me is right. I should not have made it like it’s an age thing. It’s not. I should have said, I’ve dealt with stubborn parents, too. LOL. Good luck.
References :

this is a natural green cleaning system that actually works a lot better than most products; and it’s green certified and can be used in alot of surface without causing damages; it was first used by professional cleaning service to clean doctor’s office and real estate buildings and you can only buy their products online!
References :
gotgreenkits.com/home.html

gotgreenkits.com/sustainability.html

organixandme.mionegroup.com/Products/
References :

Maybe it will give you some ideas… Good luck with that homework assignment!
References :

As well as buying products online, some sites below try to look for products which are produced locally, or as local as your location provides, the further a product has travelled to reach you the less eco friendly it is.

Do you have local farmers markets, local companies and businesses should be chosen if possible. this not only reduces the carbon footprint of the product but keeps money within your local community.

Do a search to see if their are any evironmental groups in your area, they often have information of this kind relevant to where you live.
References :
http://www.treehugger.com/buygreen/?dcitc=th_nav_buygreen
http://www.ecomall.com/
http://www.altereco-usa.com/main.php?section=home&subsection=main