Mr. Paul Price:

I will go first. The first question from the Senator was about equity. As Professor McMullin said, we are facing these carbon budgets and, as Professor Anderson said, this is something we have to confront. What we have to confront is the physics of it. We have not faced up to it so far, so it is really good that Ireland is doing this. It is not an easy thing to go through. The Act says "consistent with", and that is really what we are about, which is consistent with temperature targets and with equity. It seems one could start from there. If one starts from there, then one must look at the quantities. That is what Professor Anderson is doing and it is what we have done. That is what feeds into the economics. Therefore, one must have an economics of that quantity that actually hits that target.

One of the difficulties we have now with the modelling, and there were many good questions yesterday from members of the committee about modelling, modelling gaps and so forth, is that when we look at the energy modelling it is very good on the technology and so forth, but it is based on prices. It is also based on economic assumptions that assume constant future growth and equilibrium correction. These are doubtful assumptions. We have to grapple with the fact that they are doubtful and we must be thinking about what economics we can fit. We have to be thinking, therefore, in terms of what Professor Sweeney and Professor McMullin were talking about, which is how much carbon and how much reactive nitrogen can come into the country per year, because a carbon budget in emissions terms is pretty much equivalent to a forever fossil fuel budget. One must ration that in some way. There might be a little amount of CO2 removal and there might be methane reduction that can somewhat make up for that, but one has to make it all add up. The real challenge for our society is how to have an equitable transition within Ireland that works in the global sense too and adds up. The economics of the prices we put into models now do not necessarily reflect that at all. They just reflect our current needs or wants rather than the reality. If economics do not join up with the physics, we are in trouble.