Health and Sustainable Development Network

The validity of carbon calculators – Jenny GriffithsI have been recording data for a while on our household carbon emissions on a website developed locally here in Woking, The Carbon Diet, http://www.carbondiet.org/.  We have entered actual data on gas and electricity consumption, petrol purchased and miles driven, and flights taken.I decided that I would like to sign up to the Climate and Health Council’s CarbonDAQ group, to join in the RSA’s Personal Carbon Trading initiative (see http://www.rsacarbonlimited.org/article.aspa?pageid=914).  CarbonDAQ uses carbon footprints from the Government’s calculator, http://www.actonCo2.direct.gov.uk/index.html, which is questionnaire-based.  My personal results from the two calculators are shown in the table below:

 

Carbon Diet

Annual

tonnes

CO2

 

ActonCo2

Annual

tonnes

CO2

 

National average[1]

Annual

tonnes

CO2

 

Gas

1.41

49%

Home heating

2.65

52%

Gas

2.0

36%

Electricity

0.56

19%[2]

Appliances

1.09

21%

Electricity

0.8

14%

Car

0.75

26%

Travel

1.36

27%

Car

1.2

22%

Flights

0.18

6%[3]

 

 

 

Flights

1.0

18%

 

 

 

 

 

 

Public transport

0.5

9%

TOTAL

2.91

100%

TOTAL

5.01

100%

TOTAL

5.5

100%

The ActonCo2 calculation is two thirds greater than the data-based calculation from The Carbon Diet.  (I think ActonCo2 probably makes some allowance for public transport usage, through indirect questioning, which is not included in The Carbon Diet.)

[1] See Faculty of Public Health, Sustaining a Healthy Future: Taking action on climate change. http://www.fph.org.uk

[2] This ignores the green electricity tariff, and that we export electricity to the national grid from our photovoltaic cells to the equivalent of about two thirds of our electricity consumption

[3] This was just one return flight from Luton to Galway, Ireland for a consensus conference!  The Carbon Diet calculates the emissions precisely.

At the moment, I do not feel I want to join the RSA Personal Carbon Trading scheme as my participation would not be based on my understanding of our carbon emissions.Of course, the carbon footprints in the table are not complete.  Nationally, 4.5 tonnes of our total carbon emissions of around 10 tonnes per annum come from our work, the public services infrastructure that we use, and food and other purchases.  I would have to do a lot more work to calculate my full carbon footprint.  I must try to do it soon.I work from home (so energy consumed at work is partly included in the above figures), but travel frequently by train to meetings … I think we are quite modest in our shopping habits … but I would imagine that my total annual footprint must be in excess of 5 tonnes, so I have a long way to go to reduce to the 2 tonnes per annum – at most – that is my sustainable and equitable share.PS.  I have also completed the questionnaire on www.footprint.wwf.org.uk, the World Wildlife Fund calculator.  This calculated my footprint as 9.47 tonnes.  This calculator includes food (16%), travel (23%), home (31%) and stuff (30%), so it is far more comprehensive, although the questions are again superficial and not based on data.