If you reduce your carbon emissions below your assigned
quota then you can sell the remainder to someone who is willing to pay to continue emitting greater
amounts of carbon. The system would include both individual quotas and a national quota to be allocated
(or sold) to industry, commerce and government agencies, etc. Initially the quota would be only marginally
less than current emission levels, but over time (with annual reductions) the quota would be lowered to
levels that ensure the 90% emission decrease required in most developed countries to maintain a liveable
planet.