Canada must put a price tag on carbon emissions and then develop a carbon tax system to target emitters, a new federal report recommends. The report was released Monday by an independent advisory panel commissioned by the federal government to study ways Canada can make major, long-term cuts to the country's greenhouse gas emissions. The report, which comes after more than a year of research, concludes that the only way to make truly deep cuts, in keeping with the current government's plan to reduce emissions by about 65 per cent from 2006 levels by 2050, is to start charging for carbon as soon as possible. "As long as there is free carbon, and carbon can be emitted freely, it will be extremely challenging to achieve any significant reductions," said Glen Murray, chair of the advisory panel, which is known as the National Round Table on Environment and the Economy. "Right now greenhouse gases are emitted for free. There's no...