As little as a couple of years ago, most of us would not have heard the expression carbon footprint'.

Yet today, the term is rarely out of the news.

Most recently Prince Charles declared himself carbon neutral' after cutting his emissions by nine per cent over the past year.

The carbon footprint is not only about air travel, however. It covers fuel consumption on other forms of transport such as the family car, use of energy in the home and emissions from the production of goods that we buy.

In the UK the average carbon footprint is about 12 tonnes. In Yorkshire, people pump an average of 11.4 tonnes of carbon into the atmosphere.

We asked Dr Gary Haq, of the University of York's Stockholm Environment Institute to calculate the footprint of a number of volunteers from Bradford.

Dr Haq's work is funded by Defra's Climate Change Challenge Fund, part of a nationally-funded project that includes awareness campaigns by Bradford Council.

THE BUSINESSMAN

Restaurateur Simon Dunn runs Yo Yo café bar in Little Germany and Yo-Yo bar and restaurant in Shipley. A father-of-three, he lives in Bingley with his wife Sarojini. They have three children.

Simon eats meat and fish, sometimes buys organic, and sometimes buys locally-produced food.

He travels mainly by car (medium/petrol), and does not fly.

Simon regularly turns off lights in his home and never leaves appliances on standby. He has energy-saving light bulbs, loft and wall insulation and double glazing. His spending on consumer goods is nil, and he recycles paper, plastics and glass.

Simon's carbon footprint is: 11.28 tonnes made up of: Food 0.46 (30 per cent); Travel 4.26 (37 per cent); Home 3.33 (29 per cent); Other 3.22 (4 per cent).

Simon says: "It would be very difficult to change my lifestyle at the moment. Running the restaurant and café bar is extremely time consuming. I would like to work fewer hours, then I could look at how to make changes."

THE GREEN FAMILY

Bradford businesswoman and mother-of-five Ruth Weston runs Bradford's Nappy Train, a real nappy laundering service. She eats meat and fish, sometimes buys organic food and often seeks out locally-grown produce.

The family run a car (medium/petrol) and a large diesel car for business and spend between 15 and 25 hours on the road each week. They use the bus occasionally, and do not fly at all.

The family home has loft and wall insulation, plus low-energy light bulbs. They try their best to turn lights and appliances off. Spending on consumer goods is low, and they recycle food, paper, glass, tin cans and plastics.

Ruth's carbon footprint of 11.92 tonnes breaks down into: Food 0.04 tonnes (0 per cent); Travel 5.84 tonnes (50 per cent); Home 2.41 tonnes (20 per cent); Other stuff' (spending on household goods) 3.62 tonnes (30 per cent).

Says Ruth: "I think for my larger-than average household it is pretty good. I love old furniture and trawl junk shops and accept throwaways from family and friends - David calls me Chair Rescue.

"Where would we cut down? We are trying to go down to one car for business and domestic. It will make us think about how we travel before we travel.

"I think the biggest impact would be sorting our Bradford schools so that every local school is a good school and we parents do not feel we must move further out of the city (but keep our city jobs and lifestyle) or our children must travel to distant schools.

"Within the next three years I would like to use micro-generation (each home making its roof into its own little eco-power station) for our domestic power needs."

THE VEGETARIAN

Corina McCormack lives in Baildon with her eight-year-old daughter Polly. She works at Bradford City Farm. Corina grows her own vegetables on her allotment.

A vegetarian, Corina often buys organic, and often seeks out local produce. She does not have a car or motorbike, using the bus or train, though infrequently. She doesn't take flights abroad.

Corina regularly turns off lights and appliances. She uses energy-saving lightbulbs and has double glazing. Her household spending over the past 12 months on consumer goods is low. Corina recycles food, paper, tin cans, glass and plastics.

Corina's carbon footprint is 6.65 tonnes: Food -0.01 (0 per cent); Travel 0.71 (11 per cent); Home 2.52 (38 per cent); Other 3.43 (51 per cent).

"I could definitely improve," says Corina. "My allotment has been a bit neglected, there are less crops than last year. I've had to buy local-ish' produce from the supermarket and I do buy some fruit from overseas - fairtrade or organic - and staple produce from health food stores.

"I should also switch to a green electricity company. Lack of time means I've been unable to visit farmers' markets. I try to buy fairtrade clothing but often the sizes are too big. Charity shops are good though, but I sometimes have to buy necessities from chain stores for my daughter."