The term “carbon budgets” can seem confusing because the budgets in question have nothing to do with spending money.
Instead, they apply limits on the amount of carbon every sector of the economy can generate over a set period in a bid to drive down greenhouse gas (GHG) levels.
The overall emission limits (defined in terms of million tonnes of CO2 equivalent) are set out by the independent Climate Change Advisory Council and applied in two, five-yearly carbon budgets that between them run up to 2030.
The analysis justifying the limit is technical but the figures provide great clarity on direction of travel, whether it is with regard to power generation, agriculture or manufacturing. Demands on each are different but that is factored in.
In short, this is another part of what is needed to set Ireland on course to become a climate-neutral economy by 2050.
The resulting changes will have obvious impacts on consumers and householders.
The climate crisis (and failure to force down emissions sooner) means the carbon budgets require transformational changes for society and the economy. Failing to act urgently will have grave consequences for all, the council warns.
Why are we adopting carbon budgets now?
The Government is introducing its first carbon budgets because doing so is regarded as an effective way of driving down emissions.
The world needs to halve emissions by 2030 to have a realistic chance of keeping global temperature rise to within 1.5 degrees this century. This Paris accord target is to avoid irreversible climate impacts that would threaten life on Earth.
How do we know this is the right course?
The budgets are based on the latest scientific indications, including the recent UN Intergovernmental Panel on Climate Change report, and EPA inventories and projections.
Modelling by the Science Foundation Ireland Research Centre for Energy, Climate and Marine research and innovation (MaREI) in UCC as well as Teagasc and University of Limerick informed the calculations.
This illustrates GHG quantities that would be emitted on different pathways towards meeting the 51 per cent target.
The analysis includes an examination of temperature impacts of different scenarios to ensure compliance with that Paris target.
The carbon budgets recognise deployment of CO2 removal including nature-based and technology solutions as well as mitigation within land use, land use change and forestry up to 2050 and beyond – though many technological solutions, such as “carbon capture and storage”, are not proven at scale and should not be banked on yet.
How pressing is the situation?
The report concludes that unless there are immediate, rapid and large-scale reductions in emissions, the 1.5-degree target will be beyond reach.
“The case for significantly enhanced levels of climate leadership backed up by meaningful mitigation and adaptation actions is clear,” the council notes – a message for all politicians and for the most problematic sectors.
Agriculture accounts for 37 per cent of emissions, with methane associated with beef production and dairying responsible for more than 90 per cent of these.
However, transport could prove to be the most challenging sector in the longer term. The ceilings will be equally demanding on changing the way buildings are heated and industries that are carbon intensive and heavily reliant on fossil fuels.
What happens next?
The carbon budgets go to Government and then to the Oireachtas, which will be tasked with approving them within a four-month period. Minister for Climate Eamon Ryan will oversee the process with input from relevant Ministers. Setting sectoral limits will be the most politically fraught task.
The different targets for each sector will be based on respective starting points and the relative difficulty, cost, speed and benefits of reducing emissions.
The Government will publish its revised climate action plan based on the ceilings in early November. This will feed into a new "nationally determined contribution" to be presented to Cop26 global climate conference in Glasgow.
This plan will set out indicative ranges of emissions reductions for sectors and the practical measures needed to make targets – essentially, how emissions reductions will be achieved, and when.
Mr Ryan has accepted “this will be challenging and will require fundamental changes in many parts of Irish life”, but insisted it was also an opportunity to create a cleaner, greener economy and society.
He hoped, in spite of the considerable costs and upheaval involved, “in making these changes, we will improve the health, welfare and security of all our people, as well as our environment”.