Australian: WHEN the world was edging towards its first, imperfect treaty on climate change in the mid-1990s, the US put a proposal on the table that has set the framework for the debate on carbon reduction. Uncomfortable about taxing carbon dioxide emissions, the Clinton administration suggested letting market forces do the work through a scheme of tradeable permits now known as cap and trade. Ironically, the US has never ratified the Kyoto Protocol, which expires in 2012, but its successor, …