Dr. David Styles:

I do not have a huge amount to add because it has all been articulated clearly so far.

Specifically with regard to the modelling in the land sector, we used a model which draws upon recent models we developed in the past to use for agricultural emissions for different land management and for forestry. There were some significant emissions gaps because we very much looked forward to a 2050 perspective and took the so-called "backcasting" approach. We tried to imagine what the future could look like irrespective of what it looks like now and what are the possibility of the future in terms of land use combinations that are compatible with net zero, and we worked back from that. UCC has done a bit of work on this. Because of the transformative nature of what we are looking at, my personal view is such modelling is quite useful. It does not give you any kind of right answers or predictions per sebut it shows you what is possible within the constraints of what we know we need to do to get to net zero. It is quite a useful approach and my view would be we need to encourage modelling to be perspective so that we look at future trajectories and we are not confined to extrapolations from the past, which is perhaps a danger of relying heavily on models which had been developed hitherto - often they are prioritised using data that we have had in current systems and when we are talking about transformation those systems are no longer relevant. That is a fundamental challenge. There is no easy way around it.

I fully agree with what Dr. Hanrahan and Dr. Daly have said about unified models - it would be difficult to ever achieve that - but there is great potential for coupling models and to make sure that outputs from one model are designed in a way to be compatible with data one puts through another model. The best way of making that happen is for large-scale long-term strategic research investment that encourages collaboration across institutions and research groups because that is the way that these things happen.

I would make a minor point perhaps, to finish off. It is something that we are conscious of with our backcasting approach and what could be compatible with climate neutrality in the future. The big uncertainty there from our perspective is the degree of decoupling that is possible from animal emission intensity, which could be highly sensitive to future technologies around methane abatement in cattle, etc. Things like that are very difficult to forecast and we will depend on these models being iteratively updated through time to ever come to any conclusion on that. That is one of the ways we cannot really predict the future. We will have to keep updating these models with revised parameters as the technology develops and you will never have a finished model. As Professor Ó Gallachóir has alluded to, it is an ongoing progress. That is just a little bit of insight from my side.