EVERY time we heat our homes, take a flight or drive the car, CO2 is added to the atmosphere. CO2 is a greenhouse gas and each tonne of carbon dioxide that is added to the atmosphere adds to the effect of global warming.

We are now being actively encouraged to reduce the size of our individual carbon footprints by reducing as much of our CO2 emissions as we can.

How can you do this? Well, the first step is to work out what impact you're already having on the environment. Follow out step-by-step guide to calculating your personal carbon footprint for the past 12 months: 1. Gas and heating. Find your last year's gas bills. Add up the total kilowatt hours (kWh) for the year as found on each bill. Multiply the total by 0.19 and divide by the number of adults in your household.

For oil-burners find out the number of litres of oil used in a year and multiply by 2.975.

For coal - take total weight burned in kilograms and double it.

2. Electricity. Find your last year's electricity bills. Add up the total kWh for the year. Then multiply by 0.43 and divide by the number of adults in your household.

3. Transport. Find out your car's emissions per mile (found at www.vcacarfueldata.org.uk). Multiply by the number of kilometres driven in a year (multiply miles by 1.609 to get kms). Then divide the total by 1,000.

Also, work out your use of public transport.

For your total kilometres travelled by train, multiply by 0.11.

For your total kilometres travelled by bus multiply by 0.09.

For your total kilometres travelled by Underground multiply by 0.09.

For your total kilometres travelled by ferry multiply by 0.47.

Flights - calculate the impact of your total number of flights at www.chooseclimate.org/flying.

4. Consumption - these figures are based on calculations by a carbon lifestyle specialist.

a. I have the latest of everything and eat mostly packaged convenience food - add 3,000kg.

b. I'm fairly thrifty, but buy new things when I need them and get most of my food from supermarkets - add 2,000kg.

c. I grow mostly my own organic food, shop locally, reuse and recycle - add 600kg.

5. Add all the totals up.

How you compare 1,000kg to 3,000kg - Very green.

3,000kg to 6,000kg - Nearly there.

6,000kg to 9,000kg - You're close to the national average.

9,000kg to 12,000kg - You're an over-consumer.

12,000kg to 15,000kg - You're a carbon criminal.

15,000kg to 18,000kg - You're as bad as Tony Blair.

18,000kg to 21,000kg - You're as bad as the average American.

21,000kg plus - Just terrible.

SALLY NEW: 6,001kgSally New is the campaign marketing manager for Countrywide Farmers - a company which works hard to promote sustainability and is about to launch biomass heating boilers in their stores. The company's Renewable Fuels Conference takes place next Thursday. But how did Sally rate?

Carbon footprint: 6,001kg - close to the national average.

She said: "We are quite careful at home and recycle whatever we can. We have also just rented an allotment so we can grow our own vegetables. Our house has new double glazing and in November we installed a new boiler and have noticed a difference in the heat efficiency already.

"However, where we fall down is in the use of our cars. I don't do a lot of miles but I could convert my car from petrol to LPG. I haven't taken into consideration my husband's mileage and his diesel car which would take my rating to very poor. He does significant mileage."

ALEX JACKSON: 7,634kgALEX Jackson is a 23-year-old graduate from Worcester. He was expecting his carbon footprint to be very high due to the fact he's been travelling in the last 12 months. So how did he rate?

Carbon footprint: 7,634kg - close to the national average.

He said: "I actually thought I might have had worse results than I do because the last 12 months saw me undertake a lot of travelling around Europe. But go back only five more months before that when I finished my first session of travelling and you can add on another 2,269kg - and that's without the car!

"Living a more sustainable lifestyle will be hard in the short-term. I'm currently looking to move out and rent a flat - but if it doesn't already come equipped with solar panels etc, then I'm afraid I wont be able to invest in doing it up accordingly. I may look into getting those energy saving light-bulbs though.

"The simpler devices would appeal more to me."

SIMON KENTON: 3,241kgSIMON Kenton is a self-confessed hippie'. He is the project co-ordinator for Worcestershire Resource Exchange and lives on a canal boat. So how did this green warrior fare?

Carbon footprint: 3,241kg - close to the very best.

Simon uses 39kg of propane gas a year for cooking, a wood-fired stove sourced from sustainable woodland for heating. For his electricity he has a bank of 12v batteries charged for one hour a day by a diesel engine and he rides a push bike. He does around 4,000 miles a year in a combination of a 1.8 litre diesel van and a 4 litre camper van which uses biodiesel half of the time. He travels around 600 miles a year by train and takes two flights to Luxembourg twice a year.

"How I live now makes me very aware of the effect I have on my own personal environment. If everyone just did a little bit then it would help - for instance, just buying local food."

Follow our 16 tips to lessen your impact on the planetHOW you can reduce your carbon footprint According to the website www.carbonfootprint.com there are lots of ways to start reducing your carbon footprint, including: 1. Sign up to a green energy supplier, which will supply electricity from renewable sources (eg. wind and hydroelectric power) - this will reduce your carbon footprint contribution from electricity to zero.

2. Turn it off when not in use (lights, television, DVD player, stereo, computer etc).

3. Turn down the central heating slightly (try just 1 to 2 degrees C).

4. Turn down the water heating setting (just two degrees will make a significant saving).

5. Check the central heating timer setting - remember there is no point heating the house after you have left for work.

6. Fill your dishwasher and washing machine with a full load - this will save you water, electricity and washing powder.

7. Fill the kettle with only as much water as you need.

8. Unplug your mobile phone as soon as it has finished charging.

9. Defrost your fridge/freezer regularly.

10. Do your weekly shopping in a single trip.

11. Hang out the washing to dry rather than tumble drying it.

12. Go for a run rather than drive to the gym.

13. Fit energy-saving light bulbs.

14. Install thermostatic valves on your radiators.

15. Insulate your hot water tank, your loft and your walls.

16. Recycle your grey water.