If those costs are reflected in the market price of the carbon emissions sources (which they currently are not), then people can accurately consider those costs in making their purchasing decisions. (treehugger.com)
Initial allowances to emit emissions were overly generous, making the market price of carbon too low and the scheme ineffective. (politics.co.uk)
It clearly has had its problems but this has been because of the low price of carbon and the failure of governments to guarantee its existence into the future. (globaleducationmagazine.com)