A carbon budget represents the total amount of greenhouse gas emissions that may be released during an agreed period. In Ireland, this is measured on an economy-wide basis, excluding aviation and maritime, in megatonnes of carbon dioxide equivalent over a five-year period. Carbon budgets are used in climate policy and act as a benchmark to help ensure sustained emissions reductions over a period of time. 

The objective of a carbon budget is to set and keep Ireland on a pathway to climate neutrality by 2050. If we do not achieve one of our carbon budgets (e.g., by emitting more greenhouse gases than permitted in the budget period), the budget for the next period is reduced.  

Other countries also use carbon budgets that guide them on a pathway to reach their national climate targets with similarities and differences in the process taken to calculate their carbon budgets. For example, France also uses carbon budgets, but the French baseline year for calculating its carbon budget is 1990, compared to Ireland’s baseline year 2018.  

The Council is responsible for proposing five-year economy-wide carbon budgets to Government for approval. In October 2021, the Council proposed three five-year economy-wide carbon budgets, covering the periods 2021-2025 (CB1), 2026-2030 (CB2) and a provisional budget for 2031-2035 (CB3). Dáil Éireann approved the budgets in April 2022. 

In December 2024, the Council submitted a proposal for a finalised CB3 (2031-2035) and a provisional Carbon Budget 4 (2036-2040).   

The Act states that the Minister may revise a carbon budget ‘where new obligations are imposed on the State under the law of the European Union or any international agreement’ or where ‘there are significant developments in scientific knowledge in relation to climate change.’ Furthermore, the Minister must make a revision to the next carbon budget arising from an exceedance and may make a revision if total emissions are lower than the carbon budget for any period.

In any of these cases, the Minister is obliged to consult with and consider the advice of the Climate Change Advisory Council prior to requesting the approval of the Government in relation to a revision of a carbon budget.

The Government agreed the carbon budgets for the first two 5-year periods, 2021-2025 (Carbon Budget 1) and 2026-2030 (Carbon Budget 2).  

 The Council has provided the Minister with its proposal for a carbon budget for 2031-2035 (Carbon Budget 3) and a provisional carbon budget for 2036-2040 (Carbon Budget 4). This proposal will assist the Government in achieving its national climate objective.   

They are as follows:  

The below figure produced by the Environmental Protection Agency (EPA) shows that by the end of 2023 Ireland had used 63.9% of its first carbon budget and had 36.1% carbon budget left to the end of 2025. [1]

After 2025, if the total greenhouse gas emissions for 2021-2025 exceeds the 295 Mt CO₂eq carbon budget for that period, the Minister for the Environment, Climate, and Communications will carry forward the excess emissions from the 2021-2025 period to the second budget period 2026-2030. The second carbon budget (200 Mt CO₂eq) will then be decreased by the amount of greenhouse gas emissions that are carried forward. This ultimately makes it more challenging to meet the second and subsequent carbon budgets.

[1] Ireland's Provisional Greenhouse Gas Emissions 1990-2023 | Environmental Protection Agency (epa.ie)

The Council proposed the Carbon Budget Proposal for CB3 and provisional CB4 to the Minister of the Environment, Climate and Communications in December 2024. The Minister must present the proposal to both Houses of the Oireachtas within four months and can amend the proposal within this period. Following the presentation of the proposal, Dáil Éireann can refer the carbon budget proposal to a Joint Oireachtas Committee which will consider the carbon budget and provide a report in writing containing its recommendations to both Houses of the Oireachtas. Once the Minster finalises the carbon budget it must be submitted to Government for approval and lastly, should be laid before both Houses of the Oireachtas for approval.

After approval in the Oireachtas the Minister will use carbon budgets to prepare sectoral emissions ceilings for relevant sectors of the economy. Sectoral emissions ceilings refer to the total amount of permitted greenhouse gas emissions that each sector of the economy can produce during a specific carbon budget period.

The Climate Action and Low Carbon Development Act 2021 states that the Minister shall prepare, within the limits of the carbon budget, the sectoral emissions ceilings. These ceilings set out the maximum amount of greenhouse gas emissions that are permitted in each sector of the economy during a carbon budget period. The Act requires that the Minister finalises and submits sectoral emissions ceilings to the Government for approval as soon as may be after a carbon budget takes effect.

The Government developed and approved the first sectoral emissions ceilings for carbon budget periods 2021-2025 and 2026-2030 in Q3 2022.

As stated in the Climate Action and Low Carbon Development Act 2021, the carbon budgets proposed must match national ambition and international obligations. The proposed carbon budgets are consistent with an appropriate contribution by the State to global efforts of limiting the global average temperature increase to 1.5℃ above pre-industrial levels and to limiting the increase of global temperatures to well below 2 ℃ pre-industrial levels as articulated in the Paris Agreement.

The development of EU legislation and Ireland’s compliance with new targets was considered as part of the carbon budgets process. For example, the European Commission recently recommended a 2040 climate target of a 90% reduction in net GHG emissions by 2040 relative to 1990 levels.[1] The EU has not formally adopted this target, nor has it indicated how Member States will be allocated different targets, or whether sectors will be treated differently. However, to be consistent with expected EU policy, only scenarios for the energy system that meet a 90% reduction by 2040 or earlier were considered for the Council’s carbon budget proposal.

[1] European Commission (2024). Europe's 2040 climate target and path to climate neutrality by 2050 building a sustainable, just and prosperous society. [online] https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=COM%3A2024%3A63%3AFIN [accessed 20.11.2024].

Human activities give rise to the emissions of a large number of different greenhouse gases, leading to climate change.  Greenhouse gas emission metrics are used to compare emissions of different greenhouse gases in terms of a common unit, based on the estimated impact of emissions on some aspect of the climate system. Under the UNFCCC, it has long been agreed to use the Global Warming Potential with a time horizon of 100 years (GWP₁₀₀) as the standard common metric. Thus, GHG emissions are currently reported in CO₂-equivalents (CO₂-eq) using with GWP₁₀₀ values published in the International Panel on Climate Change (IPCC) Working Group I to the Fifth Assessment Report 5, 2014 (AR5). International reporting rules mandate the use of AR5 of GWP₁₀₀ values for reporting emissions under the Paris Agreement. This is reflected in Ireland’s climate legislation.[1]

In Ireland, annual average emissions per capita in 2022 were 12.5 tonnes measured in CO₂ eq (GWP₁₀₀). 

For reference, the values for GWP₁₀₀ are given in the table for the three main greenhouse gases based on AR5.

 [1] The IPCC AR6, 2023, WGI and WGIII reports contain updated emission metric values, evaluations of alternative metrics regarding mitigation objectives, and assess new approaches to aggregating gases. However, current reporting rules are likely to remain in place.

The AR6 notes that choice of metric depends on the purpose of the analysis and all GHG emission metrics have limitations and uncertainties, given that they simplify the complexity of the physical climate system and its response to past and future GHG emissions.

Carbon Budgets ensure that there will be sustained actions from Government to ensure that the Irish economy is on a rapid transition to a low carbon economy. We will see actions across all sectors of the economy.

We are already experiencing the impacts of climate change, and it will continue to affect our society, economy and ecosystem. The carbon budget informs the development of actions in the Climate Action Plan which aim at keeping Ireland on a pathway to achieving climate neutrality by 2050. The actions encourage and incentivise the individual and societal changes necessary to protect future generations and safeguard natural habitats and biodiversity.

The Act was originally passed by Government in 2015, with significant amendments made in 2021. The 2015 Act established the Climate Change Advisory Council to provide independent advice to Government on climate action. One of the roles of the Council is to provide an annual review of progress towards objectives across the full range of climate policy.

The 2021 amendments strengthened the provisions of the Act by adding a legally binding national climate objective. This objective commits to pursue and achieve no later than 2050, the transition to a climate resilient, biodiversity-rich, environmentally sustainable, and climate-neutral economy. The Act also provides for the development of carbon budgets and gives the Climate Change Advisory Council responsibility for proposing carbon budgets to the Minister for the Environment, Climate and Communications.

The consolidated Act can be found here: https://revisedacts.lawreform.ie/eli/2015/act/46/revised/en/html