Dr. Paul Deane:

They are larger than that. Professor McMullin mentioned a carbon budget of approximately 400 million megatonnes of carbon dioxide. We suggest about 440 megatonnes. We have looked at a wide range of potential carbon budgets, ranging from 120 million megatonnes to 700 million megatonnes, which would mean reducing our emissions to zero within the next three to 15 years, depending on our level of ambition and transition speed. However, some of those strict scenarios are infeasible and our current level of economic activity could not be maintained while achieving those emission reductions.

We do not examine emissions outside of our territorial emissions. According to the UNFCCC, Ireland is only responsible for the emissions that occur within its territory. Within our science, we do not assess emissions that come from outside Ireland.

I refer to gas as a transitional fuel. Our research shows a number of clear pathways for the future, including those of low regret and least regret. These would require massive energy efficiency, behavioural change and significant deployment of renewable and variable renewable resources. It must be borne in mind that we are starting from a point where 5% of all our energy comes from wind, which is double the global average. However, going from 5% to 80% or 90% in such a short a period would result in logistical issues and turnover challenges. Ireland needs to massively increase the role of variable renewables, but doing that before 2050 will be very difficult. That is where the role of gas as a transitional fuel comes in. The gas itself must be linked to a technology such as hydrogen production, as Professor McMullin mentioned, which is what the UK is looking at for its 2050 strategy. It seems unusual but it will use natural gas to produce hydrogen, break apart the natural gas molecules, use the hydrogen, and store the gas back in the ground. This technology has not yet been commercially tested on a large scale, but neither has 100% deployment of widescale variable renewables.

In Ireland, a low-regrets or no-regrets policy will mean massive deployment of energy efficiency and variable renewables and greater interconnection. That will get us so far. It will probably get us to approximately 70%. If we are to go beyond that, we have to examine some trickier choices. For example, we will have to look at where we get the hydrogen from and how we provide back-up to ensure the electricity system is resilient and reliable on days when there is not enough weather over Norway.