There's a lot there. To start, we're very interested in the issue. We're undertaking an audit on carbon pricing, so stay tuned for that report from us later this year.
I would not agree with the proposition that it is not having an impact. I answered the question of whether I knew the exact number of megatonnes that the impact has been. That's a different question from whether there has been any impact.
Economic modelling has shown that pricing-in previous externalities such as greenhouse gas emissions can affect behaviour in a positive way if the price is at a level that signals enough to the consumer or to the producer to change that and so on. It is considered to be an efficient means of bringing about behaviour modification and therefore reducing emissions if the price is at a level that's high enough to make those changes.
Stay tuned for our carbon pricing report on that. We'll have more to say about that later this year.