Professor Hannah Daly:

I will defer the question on the PSO levy and gas network charges as it is not within my area of expertise.

I do not dispute the findings on the appropriate base year. My colleagues are more expert on climate science and international obligations, and I agree with their logic.

The Deputy asked about policy levers that could be pulled on what the SEAI calls the big five, which are the five areas I defined. The key priority in spelling out these five measures is that, in many cases, there is confusion as to what is the most appropriate way forward in terms of decarbonising the energy system. There may be a perception that different measures are optional or that measures that are weak and inappropriate can be scaled up to a large extent. I mentioned, for example, that biogas will play a small part in meeting emissions reductions targets. Its impact is relatively small compared with the big five measures and it is very difficult to scale up because of the very large land requirement for biogas and the associated expense and competition with other land uses. The reason we set out the big five is to create a vision for the direction in which we should all be pulling to 2030 and beyond to get off fossil fuels as quickly as possible. The international consensus in energy terms is that renewables and electrification are the main pathway, rather than bioenergy or hydrogen, which are far more difficult to scale.

Regarding policy levers, one of the challenges in communicating and implementing carbon budgets in the energy system is that there is no simple policy lever to pull. Going on simple heuristics, we have a carbon price on fossil fuel emissions that is appropriate but it is currently a very weak signal because we are still adding fossil fuel infrastructure to the energy system. By "fossil fuel infrastructure" I mean fossil fuel vehicles, boilers and data centres that run on gas. We are not focusing on scaling down. First, we are not immediately ending the expansion of any equipment that sells fossil fuels - unfortunately, we are speaking about building LNG import terminals - and then we are not actively downscaling the fossil fuel sector, which would include the gas networks.

At the same time, fossil fuels are in everything we do - they are in our electricity, transport, heat and industry - so there has to be a very careful process of replacing them with efficiency, electrification and renewables within every home, factory and business and in our power sector. That is not a trivial matter.