Someone once said that only two things were inevitable, death and taxes. In many areas of life the necessity of raising funds to pay for government expenditure can lead to taxes which discourage activities which benefit society, such as employment and investment. A tax on carbon, on the other hand, would raise funds by discouraging something which is harmful to society.
Many countries already heavily tax certain sources of carbon dioxide emissions such as vehicle fuel, but few have introduced a systematic approach. A carbon tax would add a certain amount on to the cost of any activity which produced a greenhouse gas. By increasing the cost it should reduce the popularity of that activity, and consequently reduce the amount of CO2 emitted.
Rather than being seen as adding to the general burden of taxation it would be essential that other taxes were lowered at the same time. If a nation raised $10 billion via a new carbon tax it would be desirable to reduce, for example, income taxes by $10 billion so that the overall share of a nation's wealth being taken by the state does not increase.
Such a move would lead to the discouragement of something which is bad (greenhouse gases) and the encouragement of something which is good (employment), and should be both fairer and a stimulus to economic growth.
The idea of an international carbon tax whereby every nation agrees to tax carbon by a certain amount has been floated as a possible way to reduce carbon emissions worldwide. In the search for a widely acceptable alternative after Kyoto, a global carbon tax could be a possibility.