What's your carbon footprint?

Knowing the scale of your emissions is the first step to reducing them. Donnachadh McCarthy shows you how to do the maths

Thursday, 14 December 2006

Bookmark & Share

What are these?

It is my ambition that boasting about how carbon fit we are will be the new way of keeping up with the Joneses. Rather than having guilt trips about carbon diets or fretting about carbon rationing, it is more enjoyable to calculate our energy carbon footprint and have fun making it slimmer and fitter. A bonus is that making our carbon footprint healthier often results in our being healthier physically. But we need a simple means of calculating what our footprint actually is.

Anyone looking at last weekend's national adverts by the Carbon Trust showing how our national carbon footprint was divided up among the various sectors, such as industry, transport etc, would be at a loss to know how to take action themselves to reduce their own footprint. Confusingly, there are dozens of ways in which carbon footprints are calculated. My preference is to keep it to those things that are easily measurable by people in their day-to-day lives and to give guidance on those issues that really require detailed academic research, such as how to calculate how much carbon was created in putting our particular stuffed turkey onto the dinner plate.

As a home eco-auditor, I get people to calculate how much electricity, gas, heating oil, coal, petrol or diesel they used and the return flights that they took in the previous year. Simple calculations then convert these figures into tonnes of carbon dioxide and their energy carbon footprint for the year.

Almost everything we do in life, from breathing (humans, like all other animals, breath in oxygen and breath out carbon dioxide) to using water or buying furniture to eating food will result in carbon dioxide emissions. The essential message is that wasteful consumption leads to increased levels of carbon dioxide, which is leading to climate catastrophe. One way of getting this across is to start measuring the amount of water people have used and the amount of un-recycled rubbish they dumped in the previous year.

Six weeks ago, the Stern Report graphically set out the economic threat posed by climate change, not to mention the humanitarian and environmental devastation. The Government's response has been criminally complacent.

So it is up to us individuals to show the Government what can be done. In carrying out home and business eco-audits, I come across an enormous range of carbon footprints in my domestic clients, ranging from the highest, at 66 tonnes for a well-off Hertfordshire family with a swimming pool, to the lowest, with an astonishingly small 1.7 tonnes for the entire family of Friends of the Earth press officer Neil Verlander, which eclipsed what I thought was my own excellent energy carbon footprint this year of half a tonne for my home and 1.8 tonnes for flying.

Thus over 75 per cent of my emissions were made up of three flights, one for work, one for a yoga holiday and one to see a sick family member. The average household emissions in the UK is 6.2 tonnes according to Defra.

The following sections will show you whether you need a carbon fitness diet like the Hertfordshire family or are already carbon fit like the Verlander family:

ELECTRICITY

HOW TO CALCULATE IT

Electricity production emits 40 per cent of carbon emissions worldwide due to burning of fossil fuels such as coal, oil and gas in power stations to produce it. To find out your electricity carbon footprint, look at your electricity bills for the past year to see how many kilowatt hours you have used. The figures will have kwh beside them and you subtract the reading for the start of the year from the reading at the end of the year. Then simply multiply this figure by 0.43 and it will give you your footprint in kg of CO2.

Thus for example if your bills say you used the average household 5,200kwh in the past year, the calculation would be as follows:

5,200kwh x 0.43 = 2,200kg = 2.2 tonnes carbon dioxide

HOW TO REDUCE IT

The easiest ways to slim this down would be to switch to energy-savings bulbs, join a green electricity tariff from Ecotricity or Good Energy, and ensure that the timer for your electric immersion heater is set to the shortest time practical. And avoid the green plague of halogen lighting. I visited a client whose total wattage for lighting reached an astronomical 13,000 watts, due to having his home "refurbished" with these tacky eco-monsters.

GAS/OIL

HOW TO CALCULATE IT

Gas and oil emit far less carbon dioxide per kilowatt hour than electricity, but because they heat your home and water, both of which take large amounts of energy, they usually contribute a larger amount to your carbon excess fat. To calculate your gas footprint, again look at the past year's bills and see how many kwh of gas you used. You then multiply this figure by 0.19. Thus if you have the average household gas consumption of 33,500kwh, the calculation would be as follows:

33,500kwh x 0.19 = 6,400kg = 6.4 tonnes

If you used 2,000 litres of oil, the calculation would be:

2,000 x 2.68 = 5,360kg = 5.4 tonnes

For 2.5 tonnes of coal, the calculation would be:

2.5 x 2.42 = 6,000kg = 6 tonnes

HOW TO REDUCE IT

Hyper-insulate your roof, doors, walls and windows. Turn the room heating thermostat down to 19C and, most importantly, ensure that you are heating only the rooms you are occupying. If your gas boiler is over 15 years old, installing a new condensing boiler would cut your emissions by a figure-hugging 30 per cent.

CAR USE

HOW TO CALCULATE IT

Surface transport contributes over 20 per cent of UK carbon dioxide emissions. Much of this is due to private car use. The average UK motorist drives 8,700 miles a year and the calculation is as follows:

8,700 miles x 3.6 = 3,100 = 3.1 tonnes

HOW TO REDUCE IT

Use a bicycle for journeys under four miles and if you have to have a car, ensure that when you change it, you exchange it for the lowest emissions in the smallest class of car required for your needs. Different makes of cars, even within the same class, can actually use up to 30 per cent less in carbon dioxide emissions.

FLIGHTS

HOW TO CALCULATE IT

Flights constitute only 2 per cent of UK emissions. But this obscures the fact that, for the rich, flights contribute a huge amount of their carbon unfitness. A flight to New York contributes 1.2 tonnes, while a flight to Japan uses two tonnes. New Zealanders emit a whopping 4.2 tonnes to fly home. With budget airlines causing an explosion in flying, emissions are expected to double in the next 30 years, thus requiring even more dramatic cuts in other emissions, if we are to avoid irreversible climate disaster.

HOW TO REDUCE IT

Long-haul flights for long weekends should be avoided if at all possible, while replacing short-haul flights to nearby continental countries with train journeys will cut emissions by up to 90 per cent. The Carbon Neutral website will provide emissions between almost every airport worldwide, while the National Energy Foundation website converts miles flown into tonnes of carbon dioxide.

NON-DIRECT ENERGY EMISSIONS

While the above constitutes our measurable, direct-energy carbon footprint, this does not mean that other sources of emissions should be ignored. For example, the UK emits 3 million tonnes of carbon dioxide pumping water around the country every year. The average personal daily water usage in London is 160 litres. Similarly, meat consumption has a massive carbon footprint, with methane and other emissions from cows and livestock contributing over 18 per cent to global emissions.

Donnachadh McCarthy is the author of Saving the Planet Without Costing the Earth (Vision Paperbacks) and works as a home and business eco-auditor. www.3acorns.co.uk

Your annual carbon/eco footprint

ELECTRICITY METER READING

Reading this year:

Less reading last year:

Total number of kwh for year:

Multiply by 0.42 to get kg CO2 emitted:

Divide this figure by 1,000 to get the number of tonnes of CO2 emitted:

GAS METER READING

Reading this year:

Less reading last year:

Total kwh for year:

Multiply by 0.19 to get kg CO2 emitted: