Mr. Greg Muttitt:

We found that if the projections of emissions under the sustainable development scenario are used, the 2°C carbon budget is fully exhausted at the end of that scenario in 2040 and requires emissions to suddenly drop to zero in 2040. The reason, as can be seen from the vertical red line in my graph, is there is a two in three chance of staying below 2°C rather than a 50:50 chance, and thus trying to get a bit closer to the Paris goals. A second reason is the IEA makes rather unfeasible assumptions about what will happen outside of the energy system to make more room for energy emissions. For instance, the agency conducted a study on how to allocate carbon budgets, and gave 90 gigatons for the rest of the century to non-energy emissions. That is just 15 years worth at current levels and primarily stems from land use change and cement calcination. In my graph we estimated the most optimistic feasible level, which is about double that amount. That requires both significant reforestation and the best plausible technology that can be achieved this century, according to the IEA's cement roadmap. Apart from applying a lower probability of achieving the goal of 2°C, the IEA has assumed that more action will happen outside the energy system than I would say is feasible.

I shall return to the point made about carbon capture and storage, CCS, by Mr. Brendan Murphy. That is the third difference between the two.

A fortnight ago, Mr. Gould argued that the IEA's sustainable development scenario was consistent with other scenarios that led to a 1.8°C outcome. His claim is only true if one assumes a significant proportion of the excess emissions that occur during the scenario period are later sucked back out of the atmosphere using negative emissions technologies. Such technologies exist in the theoretical models but have never been applied in practice. Bioenergy technology has been used reasonably extensively and CCS technology has been used in a number of pilots worldwide. However, no one has tried to marry the two technologies to see how CCS copes with the more variable CO2 streams that come from bioenergy than from fossil fuels. In addition, even if the technology works and is affordable, when one considers some of the studies, of which there have been a number over the past couple of years, and considers what that would entail in terms of land area, then some of the scenarios that the IEA uses for comparison would require a land area devoted to bioenergy that is 12 times the size of India.

When we imagine that later in the century, with a likely larger global population, devoting that much land to bioenergy could have an extremely disruptive effect on food supplies.

Looking at a natural decline rate of between 4% and 7% in oil and gas fields, that is the kind of decline rate that is aligned with the Paris goals. The IEA uses a scenario that is not aligned with the Paris goals to suggest that the transition will be slower. If we look at the numbers in the Paris goals, even for a 2°C target we are looking at about a 5% global reduction in emissions per year. The target in Ireland is reducing greenhouse gas emissions by 80% to 95% by 2050. I have got the numbers in my written submission, but that is an annual reduction of between 7% and 10% per year in emission from fossil fuels.

What we are talking about here is a natural decline rate that is aligned with the Paris goals. It is not, of course, aligned with scenarios that fall short of the Paris goals. Deputy Ryan also asked about the IEA's point that oil and gas are used in a number of other applications. The non-combustion uses are relatively small. About 15% of global oil is used in non-combustion purposes, primarily petrochemicals, plastics and, to a smaller extent, building materials and about 10% of global gas use is non-combustion, primarily in fertilisers. There are some other combustion uses that are much harder to replace such as aviation. Looking at Ireland specifically, and oil use in transport, approaching half of that is in passenger vehicles where alternatives through electrification are available and almost the same cost today. Turning to gas, about half of Ireland's gas use is in power generation.

As we saw in the earlier graph of IPPC scenarios, the IPPC states that power has to be the fastest sector to decarbonise because the alternative technologies are readily available and at comparable cost to fossil fuels. That is particularly important in the Irish context where there is significant agricultural activity in the economy. Agricultural emissions are much harder to mitigate than power sector emissions so that is why it is important to move at the fastest available speed when it comes to the power sector.

The final question was on how does the oil price play in this. I was asked for a prediction of the oil price and I will decline that request. I have worked on oil for about 20 years and over that time I have seen people confidently predict that the oil price will never again go above $15 or never again go below $100 - it is currently about $75 - and what I find is that the more confidently people make predictions of the future price, the more likely they are to be wrong. With apologies, I decline that request but I will note that there are prospects in Ireland at the moment. Some discoveries are being appraised to see if they are viable. I have studied some of the oil industry's own data and projections on how they look and they are certainly at the more expensive end of the cost curve.

One consultancy we particularly rely on, Rystad Energy, suggests that much of the production might be viable at something approaching or around current prices of $75. The consequence for Ireland of being at the high end of the cost curve if, as has been pointed out, the price subsequently falls - for instance, if climate policy reduces demand for oil and gas - is that it will be among the countries most affected by stranded assets and the economic damage that causes.

That is a consequence of the greater production cost in Ireland compared with some other countries.

I believe I have answered all Deputy Ryan's questions. I will deal briefly with Deputy Stanley's questions because Mr. Allen is better placed to answer on many of the technical aspects, including on biogas. The Deputy first asked about the emissions comparison of gas versus coal and oil and, in particular, conventional gas versus coal and oil. Gas produces about half the emissions as coal in combustion. Slide 14 shows that where we replace the IEA's projected coal use in 2040 by gas it halves the emissions, but leads to the world being a long way off what is needed to achieve the Paris goals. At this stage of the climate problem we are no longer in the position of having to reduce emissions a little compared to a business as usual scenario. We know from the science and from the political agreement in the Paris Agreement what is a dangerous and intolerable level of climate change, and that gives us a specific amount of emissions that we can afford. We need to compare that conversion scenario not with the even worse scenario that has lots of coal in it but with the scenario up to the right of it, the green bar, which is what avoids the most severe dangers and disruptions of climate change.

On the question about the variability of renewables - Mr. Allen can talk more about this - there have been a number of studies in recent years of how we can get to high levels of renewables penetration, including 100%. I refer to some of the practitioners who have talked about this. The operator of the electrical grid in north-east Germany says its grid can handle 70% to 80% renewables, even with existing infrastructure. The Australian grid operator, TransGrid, has said it can do 100% renewable energy using existing technologies, including demand management, storage and efficiency. Germany and Australia are larger countries than Ireland and are part of larger continental land masses. TransGrid covers just about one third of Australia. They have different circumstances in some respects and every country must pursue measures that suit their circumstances. However, they demonstrate the growing ambition over recent years and the growing technological innovation in grid operators. Ireland's grid operator in one of its scenarios has up to 60% renewables penetration on the grid by 2030. The penetration in 2016 was 27%. There is room for significant growth there, but Mr. Allen can comment further on the technical aspect.

Deputy Lawless asked where storage fits in this picture. Slide 15 compares generation without storage. However, what is seen there is wind or solar compared with combined cycle gas turbine technology, which is primarily suited to base load rather than handling intermittency. Looking at the projections from Bloomberg New Energy Finance, including its new energy outlook released about three weeks ago, when one compares renewables plus storage with gas technology such as open cycle turbines, which are suited to dealing with variability, the costs are much more comparable. The storage technology is falling in cost rapidly to the extent that renewables plus storage are going to be competitive even with the base load, perhaps, in ten years or so.

The only question I have left is Mr. Murphy's about carbon capture and storage.

Carbon capture and storage is a means of burning fossil fuels while catching the majority of emissions, up to 90%, and burying them underground. Until about five years ago it was seen as the saviour of energy systems because it was thought it would allow us to keep the existing means of generating energy, using fossil fuels, while dealing with emissions. A lot has changed in the past five years and many of the proponents of CCS technology have stepped back from it, including the UK Government, the US Government, even under the Obama Administration, and many utilities. One reason is that in the 20 or 25 pilots that exist in the world for CCS applying to fossil fuels, the costs have come out as much more expensive than people were hoping they would be. It is a more costly way of mitigating emissions than renewables, even combined with technologies to deal with variations such as storage or demand management. To illustrate this, I will quote the chief executive of Enel, the Italian utility and one of the largest companies in Europe, who is also chair of the trade association, Eurelectric. He said:

I think CCS has not been successful. It doesn't work, let's call it what it is - it is simply too expensive, too cumbersome, the technology didn't fly.

In spite of the hopes of such companies that CCS would be a solution, in practice the confidence has greatly diminished and the solutions are now seen as not burning fossil fuels in the first place.

The IPCC comments on this were also referred to. The IPCC reflects the best science and has an extremely rigorous process of reviewing the already peer-reviewed science that has been published, which it does in the context of other peer-reviewed studies. It scrutinises the science and builds a consensus among scientific experts for what it all means. This appears in its assessment report which comes out every five to eight years. The most recent of these was published in 2013-14 and the next will be in 2021-22. There is a lot of rigour in its process and it does not try to publish an assessment every year. The greater degree of CCS, combined with bioenergy, shown in the fifth report of 2013-14 reflects how people thought up until 2011 or 2012, the period on which the assessment report is based. However, things have moved on significantly with the lessons that have been drawn from the pilot plants over the past five years and CCS is now seen as a much less promising prospect. It was supposed to combine with bioenergy to create negative emissions but a large number of papers in the peer-reviewed literature of the past year or two, which will be for a special report the IPCC is doing on achieving a target of 1.5°C and which will come out this October, show very few or no negative emissions and are looking at reducing emissions in the first place, rather than sucking them out later.

I have no objection to CCS, if it can be proved that it is safe. I am concerned about what happened with the Sleipner project in Norway which was thought to be safe until, after 20 years of operation, it was found not to be. If the experts can demonstrate that it is safe, that is fine, but let us not make decisions today, such as expanding our fossil fuels, on the assumption that someone later will make these technologies work. That would be unprecautionary and unwise.