They may just make a tiny difference, but multiplied by lots of people doing lots of things, we can have a real impact. So here are a few simple things you can do to start helping the environment.

1. GreenScore yourself

Take the GreenScore test to see how green you are. Answer a simple questionnaire, which covers around 80 practical things you can do to become more energy efficient, reduce the impact of your travel, save water, shop sensibly, and reduce, reuse and recycle your rubbish.

How did you score? You know you can do better! So now's the time to try. Get together with a group of friends and over the next six months each of you try to reduce your environmental impact from energy and water use, household waste, transport and shopping. Then take another GreenScore test to measure your improvement. See which of you can do the best. If you all improve your scores, this will help create a cleaner, more sustainable future for everyone.

2. Do the Green Thing

Do The Green Thing is a fun website which gives you one really simple thing to do each month. Just sign up to do it, do it each month and tell them you've done it. You'll be joining tens of thousands of people around the world who are doing The Green Thing.

You might be asked to take a walk rather than going by car. It's that simple. Or you could go to bed early one night and save electricity at the same time. Sound easy? That's because it is, and if you do a little thing once you might want to go on and do it more.

3. Plant a tree

Why are trees good for the environment? Here are a few reasons from the Trees are Good website of the International Society of Arboriculture:

• Trees renew our air supply by absorbing carbon dioxide and producing oxygen;
• Two mature trees can provide enough oxygen for a family of four. One tree produces nearly 260 pounds of oxygen per year;
• One acre of trees removes up to 2.6 tons of carbon dioxide each year;
• Shade trees can protect against fierce sunlight and make buildings up to 20 degrees Fahrenheit cooler in the summer;
• Trees cool the air by evaporating water in their leaves;
• Tree roots stabilise soil and prevent erosion;
• Trees improve water quality by slowing and filtering rain water, as well as protecting aquifers and watersheds.

Convinced? Here's how to do it:

1. Save five empty ice cream tubs;
2. Fill these with earth;
3. Find some seeds, perhaps acorns if you want to plant oak trees;
4. Plant the seeds in the earth;
5. Put the tubs in sunny window;
6. Water from time to time;
7. Watch the seeds germinate and grow into small trees;
8. Add some plant food if you feel that your trees are getting hungry;
9. Transplant into a bigger pot as your trees grow;
10. Then find a suitable spot to put your trees - on a bit of waste land, on the canal towpath or at the edge of an existing grove of trees. You've now become a guerilla tree planter!

Visit your trees as they grow. Look after them and take pride in what you have done.

4. Give up bottled water

The bottled water phenomenon is one of the curiosities of our age. It is an expensive purchase (often more than an equivalent amount of petrol) of something which is normally available free and on tap. The global spend on bottled water is now around $100 billion annually, and this money could be used to bring clean fresh water to every human being on the planet with some spare change left over.

Bottled water also pollutes. It isn't just the disposal of the bottles (plastic or glass) but also the carbon footprint it leaves. All those lorries travelling from source to bottling plant to distribution centre to supermarket cause congestion and pollution for all of us. As our concern with global warming increases, drinking bottled water looks an insane act in today's world.

Limit the amount of plastic bags you use

So take the first step by getting a glass from the cupboard and filling it up from the tap, then drink it. As you are doing this, make a pledge to give up bottled water. If you like having a bottle of water in your bag as you're on the go, invest in a screw-top bottle from an outdoor adventure shop and refill it at home before you leave the house. You'll never need to buy a bottle again.

And while you think about it, pledge to become a bottled water activist. Spread the message and see how many people you can get to give up bottled water.

5. Say NO to plastic bags

Every time you go shopping, you're probably doing something that harms the environment - even if you walk or cycle to get there. The plastic bags you carry your shopping home in will be used for just a few minutes, but the bags may last for between 15 and 1,000 years, depending on whether they are bio-degradable.

Plastic bag litter creates big problems. The bags can trap birds or kill animals if eaten. They can block drains and foul rivers and canals. They can accumulate along the roadside or on beaches. They can be a blot on the landscape as well as an environmental hazard.

So take a stand and use reusable bags for your shopping. Buy cloth bags, jute bags, straw bags, bags made out of recycled bottle tops and use these instead. Take one with you whenever you go out shopping. And use them again and again and again. And if you do take plastic bags home with you, recycle them as bin liners or freezer bags.

For more ideas on how to change the world, read Michael Norton's 365 Ways to Change the World, which has an idea and simple actions for each day of the year. And check out http://www.365act.com/

Article produced by the Choose Action Alliance.

Updated: 27/10/2009