I'm against carbon taxes, precisely because governments treat taxes as income they can spend on other things.

Unless the money is being used to directly offset and minimise carbon production, the idea of a carbon tax is another clueless sop to the 'markets will fix everything' belief, with a bit of statist spin.

What's needed is carbon rationing. If you don't use your allowance, you can sell it. If you need to use more than your allowance, you'll need to buy it at the going rate.

Governments should administer the scheme, and take a cut from sales which can be spent on carbon mitigation, sustainable R&D and policy research to retool the entire economy in a more sustainable direction - not just by making obvious energy savings, but by restructuring food production, commuting, and other pre-carbon traditions.