UK citizen’s emit about 13 tonnes of CO2 each per year including ‘consumption’. Direct emissions (ie those you are directly responsible for by travelling or using energy in your home) are about 5.6tonnes of CO2 each. About 2.4tonnes is attributable to ‘government’ or ‘shared services’.
The sustainable level (ie what the world can absorb for each one of us) is presently about 1 tonne but this will reduce as population grows, carbon sinks degrade and the science realises is was underestimating. Even the conservative IPCC 4th Assessment Report calculates that we need to be a zero-carbon society by 2050 to avoid catastrophic runaway climate change.
Duncan’s personal carbon calculator for travel and household emissions on a journey by journey, bill by bill basis. His personal total for tax year 2007-08 was 2800 kgs against a UK average of about 5600kgs of direct emissions. Biggest single impact was 6000 miles of train travel = 1200kgs
Quaker Green Action has an easy and realistic carbon footprint tool.