Professor Barry McMullin:

I thank the committee for the opportunity to provide evidence on this crucial subject of Ireland’s first statutory carbon budget programme, under the Climate Action and Low Carbon Development (Amendment) Act 2021. I am a professor in the faculty of engineering and computing at DCU, researching national energy system decarbonisation. I am joined by Mr. Paul Price who is a research fellow in the faculty funded by the Climate Change Advisory Council to undertake research in the domain of carbon budgets. For the record, Mr. Price and I are appearing today in our individual academic capacities and are not representing or speaking on behalf of the Climate Change Advisory Council in any way.

My comments will focus primarily on the statutory requirement for the carbon budget programme to be consistent, in both design and execution, with the Paris Agreement and, specifically, the commitment to quantitative limits on global temperature rise, to be achieved on a basis of equity and informed by the best available science.

Under the Act, the Climate Change Advisory Council has proposed the initial programme of three five-year carbon budgets, with the third on a provisional basis. It is now up to the Oireachtas, informed by the views of this committee, to adopt these budgets as proposed or to revise them on some specified grounds. My view is that the candidate budgets proposed by the council should be regarded as absolute maxima and that the committee should give serious consideration to revising them downward significantly, by which I mean more stringent budgets. This is based on multiple lines of argument, which I will outline as briefly as possible.

The current programme for Government committed explicitly to an average reduction in total emissions of 7% per annum over the period 2021-30. Using the baseline of 2018 emissions specified in the Act, this would allow a cumulative ten-year total to 2030 of 468 Mt CO2 eq, whereas the council's proposal is for 495 Mt CO2 eq, cumulatively equivalent to a reduction rate of just under 6% per annum. While the programme for Government properly fell outside the formal legal scope of the council process, it is surely still relevant to the deliberations of this committee and of the Oireachtas. Accordingly, I suggest that the committee should consider revising down the first two proposed budgets by a combined amount of, at least, 27 Mt CO2 eq, to align them with the programme for Government. The committee should resist deflection into a narrow focus on the projected annual emissions level in 2030. This is simply not equivalent to the original programme for Government commitment on any good faith basis of best available science.

Separately, as explicitly required by the Act, the council has assessed its proposed budget programme for consistency with the Paris Agreement. It has emphasised that this assessment depends not just on the budgets, but on how they are allocated between sectors, which strongly affects the relative mitigation of different greenhouse gases, and on unavoidable value judgments required to interpret the obligations of the agreement. While it concluded that its proposed budget programme is broadly consistent, at least with the temperature goals of the agreement, it was also clear that its assessment represented only a minimal test of Paris consistency and took the position that the judgments involved ultimately go beyond the remit of the council. It is, therefore, proper that this committee should now make its own assessment and determination on all these issues.

A key aspect of this is relative historical responsibility for climate change and the need to treat this on an equitable basis between countries. Those with greater historical responsibility have a correspondingly greater obligation to act. This is a complex issue, but it directly affects the assessment of carbon budget consistency with the Paris Agreement through the choice of a reference year for temperature increase. In effect, differentiated historical responsibility between countries is waived for all emissions before this reference year. In its assessment, the council adopted a reference year of 2020, but without offering any explicit rationale for this. In previous work with colleagues at DCU and Trinity College Dublin I have argued that 2015 should be regarded as the latest defensible reference year for this purpose, it being the year when the Paris Agreement was adopted. Indeed, there is a good case for extending further back, even to 1992, when the UN Framework Convention on Climate Change was agreed. Since the council published its budget proposals, I have initiated with DCU colleagues, including Mr. Price, independent analysis of the effect of varying the reference year. Preliminary results indicate that using the council's methodology, but with a reference year of 2015, all but one of the scenarios considered by the council would then fail the council's own test for Paris Agreement consistency, strongly indicating a need for further reduction in the proposed budgets to adequately align with the intentions of the Act.

Regulations issued under the Act direct that certain emissions should be omitted from the carbon budget framework, that is, those arising from international aviation and shipping. These are significant for Ireland, amounting annually to just under 4 Mt CO2 eq, in 2018, primarily in aviation. However, the fact that accounting for such emissions falls outside the budget framework does not mean they can simply be ignored in the setting of the budgets. On the contrary, as already noted, the budget process is required to operate on a basis consistent with the Paris Agreement. Recent independent legal analysis, commissioned by the Brussels-based Transport & Environment NGO, is unequivocal that such emissions fall within the scope of the Paris Agreement. Accordingly, they must still be provided for in some way in the national budget process prescribed by the Act. The council appears to have taken the view that this particular aspect of Paris consistently fell outside the scope of its assessment. On that basis, therefore, it falls to this committee to make such provision. Again, this indicates that the proposed budgets should be reduced, at least, by the projected national share of such international aviation and shipping emissions. A minimum estimate of this would be 40 Mt CO2 eq, over the period 2021-30, which is the first two carbon budgets.

A further critical consideration is prudence, as explicitly expressed in the framework convention through the precautionary principle. The council's Paris test focused on the lower temperature goal of the Paris Agreement, that is, limiting to no more than a 1.5oC increase compared with pre-industrial conditions. This was very proper in light of the Intergovernmental Panel on Climate Change, IPCC, special report on warming of 1.5oC, indicating rapidly escalating risks of severe global disruption as this threshold is exceeded. However, the relationship between that temperature limit and the permissible global greenhouse gas budget is still subject to very significant scientific uncertainty. It appears that, in effect, the council adopted a budget based on just a 50% probability of meeting this temperature goal, that is, no better than a coin toss.

I urge the committee to explicitly consider whether this represents an adequately prudential approach. If not, then the Irish budgets should be further reduced to reflect this. It should be noted that the equity requirements of the Paris Agreement extend to at least the further dimensions of differentiated vulnerability and capacity to act and, arguably, to reparation for ongoing, severe and highly unjust impacts of climate change. While the national claim on the global carbon budget is not the sole, or indeed the main, potential mechanism for responding to these issues, I would nonetheless urge the committee to still bear them in mind in assessing overall consistency with the Paris obligations.

Moving on from the immediate adoption of the carbon budgets, the next key step under the Act will be the division of these budgets across sectors, that is, setting the sectoral emissions ceilings. As this is explicitly a Government responsibility, the council properly refrained from prescribing any single sectoral breakdown, but did provide a set of five illustrative scenarios specifically exploring different potential divisions between the two largest emissions sectors, namely, agriculture and energy, including electricity, transport and heating. This was essential to inform its assessment of consistency with the Paris temperature goal. Even though all these scenarios are designed to correspond, essentially, to the same aggregate carbon budget programme, as expressed in carbon dioxide equivalent emissions, they differ very significantly in their ultimate contribution to global warming. While the detailed interactions are complex and will benefit from further scientific analysis, it is clear that the scenarios allocating relatively larger budget shares, or lesser emissions reduction, to the agriculture sector also correspond to greater absolute levels of warming and, therefore, greater risk of failing the requirement of consistency with the Paris Agreement. I would urge the committee to give early consideration to this issue and to offer relevant advice to the Government in advance of the setting of the sectoral emissions ceilings.

While adopting the national carbon budgets and corresponding sectoral ceilings are essential steps in Ireland's climate action, their effectiveness will hinge on actual delivery. It is critical to recognise that under the 2021 Act carbon budgets are no longer mere targets to be aspired to; they are self-imposed, quantitative statutory constraints, legally binding upon the State. This is a radically new and extremely challenging framework for our political and policy institutions. This is entirely justified by the scale and urgency of the climate emergency, but it demands an urgent re-evaluation of our governance mechanisms to ensure that they are commensurate with this task. It is no longer a question of merely doing our best, we must do what is necessary. In particular, there is a very strong case for the early establishment of mechanisms to dynamically regulate, as and when necessary, the upstream inputs to Irish societal activities, such as fossil fuels, that ultimately give rise to greenhouse gas emissions. This would effectively create a backstop, ensuring that carbon budget constraints would be reliably met, regardless of shortfalls in the effectiveness of other less direct measures. Given the overriding need for justice, equity and national solidarity in these actions, this should be in the form of a system of equitable rationing. I have previously advocated for the deployment of one particular such system, known as tradeable emissions quotas, TEQs, but whether through that approach or some other, I urge the committee to consider this need for much stronger, transparent and societally inclusive, national carbon budget governance at the earliest possible opportunity.

My final comment is in regard to the international dimension of climate action. Through the 2021 Act, and the implementation of its voluntary, nationally-determined carbon budget process, explicitly bound by the Paris Agreement goals, Ireland has sought to take a leadership role in modelling how the agreement can be effectively delivered on.

However, the harsh reality remains that unless those countries responsible for the great bulk of emissions adopt similarly ambitious measures, the agreement will still fail with devastating consequences for current and future generations in all countries across the globe, including Ireland. As we celebrate the centenary of the establishment of the State, we can take some justified pride in our record as a small independent nation in advancing progressive multilateral action through active diplomacy. This was most recently manifested through our rapid mobilisation of diplomatic support from other EU member states during the ongoing Brexit process, and through our success in being elected to the UN Security Council for the 2021-22 term. I suggest that this committee now initiates an urgent collaborative activity with the Joint Committee on European Union Affairs and the Joint Committee on Foreign Affairs and Defence to consider how we can collectively upscale and prioritise Ireland's diplomatic effort on climate action so that our newly ambitious local efforts can make the maximum possible contribution to catalysing the required emergency global response.

I make these remarks on behalf of both myself and Mr. Price.