Professor Barry McMullin:

I defer to the Deputy's expertise on the political difficulties involved. In terms of the potential changes to EU accounting, as she will be well aware, changes to governance at EU level are very difficult to bring about. It is a process that unfolds very slowly. I completely agree with her that there are good arguments for Ireland to press and use its influence in the EU, in the manner that Professor Allen explained in an earlier session, to augment the accounting to better reflect to contribution to warming of different gases. That would be very beneficial. Ireland could certainly take a lead on that EU policy. On the question of international influence, I agree to an extent that what works, in the trade situation, is rules, standards and scientific measurements. However, when bringing those forward and in seeking to get other countries to buy into them, they are going to ask why we are bringing forward particular rules or changes. We will set out the argument for doing so, on the basis of the climate impact. They will point out that new rules and changes will affect them and us in various ways, and will ask why they should go along with that as part of the collective effort, if we are not playing proportionate effort in that collective effort. That is the point I was making. In terms of carbon leakage at the moment, if anything, we are on the wrong side of that equation because we are not playing our proportionate part.

The fossil versus biogenic methane timescale question is a complicated one. The only answer that I can give the Deputy is that, unfortunately, to do it properly we have to feed trajectories of all the different gases into a form of model. The GWP* methodology, which Professor Allen has explained, is effectively a simplified model for assessing the impact. One way or another, we have to feed the disaggregated gases into a model, look at scenarios for different combinations of the gases, and see what the aggregate temperature contribution would be. That is the only way to get a good answer. In the submission I made to the committee there is link to a paper that we presented just last month at an international conference in Gothenburg, in which we did exactly that in the Irish context. Using exactly the methodology explained by Professor Allen, we looked at the trade-off between reductions in Irish methane flow, doing more and less than that, and the consequence for having to do more or less CO2 removals