A new scoping study of a personal carbon allowances scheme shows that it is potentially a simple idea that could put a cap on individuals' carbon dioxide emissions in a fair and forward-looking way.

Between 40 and 50% of UK carbon dioxide emissions are caused directly by individuals.

A personal carbon allowance scheme would set a limit on these emissions by giving each individual a carbon allowance. People who need or want to emit more than their allowance would have to buy allowances from those who can emit less than their allowance.

Defra commissioned the Centre for Sustainable Energy to undertake a study of the ideas and issues involved in the concept of individual carbon trading in mid-August 2006. Many questions need to be resolved before any decisions can be made on PCAs. It remains one of the options the Government is continuing to explore.