I hear what my hon. Friend says about certainty being a pre-requisite for getting the kind of investment necessary over the term about which we are speaking. The Committee has spoken about that before: its report on the emissions trading system talks about a strong and stable carbon price signal being another component that is needed to achieve certainty and predictability, which are the pre-requisites of investment. Will he explain that to me? After all, I am on a sharp learning curve.