A bit more on my house’s carbon footprint. I buy my gas and electricity from e.on (was Powergen) they are now doing rather snazzy graphs from my energy bills 
and also calculations of actual CO2.
They have calculated in 2007 I generated 3.5 tonnes of CO2 and for 2008 it will be 4.6 tonnes (problem of having additional folks in the house).
Its a far cry from my HIPS report which thought I should be emitting 12 tonnes or if I did all their recommendations 10 tonnes.
They are also using the same measure that Prof. David Mackay used in his lecture at the Cambridge Science Festival. That is Kilowatt hours per day.
Averaging out the red line (my domestic 2007 combined energy consumption) gives me a figure of about 95kwh/d which for 2 people in the house is about 48kwh/d each.
In his talk he reckoned that UK people use about 125, in the USA about 300. With Heat at 38kwh/d and light of 4kwh/d plus gadgets of 5kwh/d it looks as though his numbers are spot on. Read his latest book in pdf form here . To see his other predictions and also read Davids blog.
