the Garnaut report and by Treasury as underpinning the difficulties of the current international discussions. After all, that logic would suggest that if we impose a unilateral tax on our exports, that only increases the gain to our resource competitors from staying out of any global agreement. But even if it were true that our action would positively affect outcomes in the rest of the world, any such effect would be slight at best and could hardly justify the costs and risks unilateral action creates. Costly now, more costly later? A third argument is to say that acting now is less expensive than acting later. However, it would surely be even more costly to take action now only to discover later it was futile. At that point, high costs would already have been incurred, not least in harming our export industries. Added costs would have to be incurred to dismantle whatever system had been put in place. Indeed, the extent of those costs was strikingly highlighted by Parliamentary Secretary for Climate Change, Mark Dreyfus , when he said that any repeal of emissions permits would require expensive compensation under section 51 (xxxi) of the Australian Constitution . In making that point, Dreyfus was merely confirming that implementing this scheme before the global framework is clear will impose very substantial risks on taxpayers. The public protests against the carbon tax AAP Business uncertainty won't go away A fourth point is to say that we need such a scheme to reduce the