Observations on Ireland's Carbon Budget 3

Published on Substack, Wednesday, 4 June 2025

This submission was made to the public consultation on the Climate Change Advisory Council's recommendations for Carbon Budget Periods CB3 (2031–2035) and CB4 (2036–2040), ahead of Minister Darragh O'Brien's recommendations to the Government [link].

Ireland has taken legislative steps to address climate change, including through its ratification of the Paris Agreement (2015) and the adoption of a legally binding system of five-year carbon budgets under the Climate Action and Low Carbon Development Act.

These budgets set national emissions ceilings of:

• 295 MtCO2eq for 2021–2025,

• 200 MtCO2eq for 2026–2030, and

• 160 MtCO2eq for 2031–2035 (as currently proposed).

  
  

However, the proposed carbon budget of 160 MtCO2eq for 2031–2035 exceeds Ireland's estimated fair share of the remaining global 1.5°C budget by 9 MtCO2eq. The figure of 151 MtCO2eq was calculated for the Climate Change Advisory Council in preparation for their budgets, which was considered an upper bound. It was relied on by the CCAC in their initial proposal for the 2031-2035 budget.

1. Carbon Debt and Global Equity

Ireland has already consumed its fair share of the global carbon budget. The rate of consumption places the country in a state of "carbon debt", intensifying climate injustice by disproportionately harming lower-emitting, more vulnerable nations that are already facing severe consequences, such as droughts, floods, and displacement.

2. Intergenerational Impact

There is a profound ethical responsibility to future generations. Continuing to exceed fair share targets will exacerbate climate-related risks—including extreme weather events, biodiversity loss, and food insecurity—facing today's children and grandchildren. As Emeritus Professor John Sweeney of Maynooth University poignantly observed in The Irish Times (24 May 2025) [link]:

"Sorry, kids. We blew your climate budget – but we really love our SUVs."

3. Legal Obligations under the Climate Act

Under the Climate Act, the Climate Change Advisory Council is legally required to exercise its functions in a manner consistent with:

• The overall objective of the UN Framework Convention on Climate Change,

• The Paris Agreement, including:

  • The 1.5°C temperature goal,

  • The principles of equity and common but differentiated responsibilities and respective capabilities, and

  • The duty to act based on equity.

The Climate Act also imposes parallel obligations on the Minister and Government when finalising carbon budgets.

4. Implications: Fair Share Carbon Budgets Required

The law, therefore, requires Ireland to adopt quantified carbon budgets that reflect principles of fairness and international equity. The requirements include setting budgets aligned with Ireland's fair share of the remaining global carbon allowance, consistent with the objective of limiting global warming to below 1.5°C.

Demonstrating equitable responsibility and a commensurate level of ambition is also essential to Ireland's role in the collective EU effort to address climate change, including through cooperative mechanisms such as the Effort Sharing Regulation (ESR).

5. Support from Human Rights Law

Under the European Convention on Human Rights Act 2003, Irish law must be interpreted in a manner compatible with the European Convention on Human Rights (ECHR). In the KlimaSeniorinnen judgment, the European Court of Human Rights (ECtHR):

• Found inadequate climate action to be a breach of Article 8 (right to private and family life);

• Emphasised the need for quantified national carbon budgets tied to the global 1.5°C limit;

• Rejected abstract or vague climate targets as insufficient.

  
  

This case highlights the human rights obligation to establish a national carbon budget in alignment with global equity and the science-based temperature goal.

6. Conclusion: Legal and Ethical Obligation to Revise CB3

Taken together, Irish climate, constitutional, and human rights law require that the State set a revised third carbon budget that does not exceed Ireland's fair share of the remaining global carbon budget. The currently proposed 160 MtCO2eq for 2031–2035 is incompatible with these obligations.

7. Recommendation

1. It is recommended that the Minister amend the provisional third carbon budget (CB3) to 151 MtCO2eq for the 2031–2035 period to comply with the legal requirements of the Climate Act, the European Convention on Human Rights Act, the EU Charter, and the Constitution.

   
   

2. While this amendment is necessary, it is equally vital that the development and implementation of climate policies, as well as the revision of the Climate Action Plan, continue without delay, irrespective of any temporary hold-up in finalising the revised carbon budgets.