What should the Carbon Budget be?

With the Climate Council now up to full strength we expect them to move quite quickly to make their recommendations on the Carbon Budgets for 2021-25, 2026 to 2030 and 2031 to 2035.

We know the Government is very keen to have the numbers in the public domain before An Taoiseach and other ministers travel to the COP at the start of November. That means the Council would need to send their proposal to Government by the end of next week at the latest to give Government the chance to digest it.

It’s unclear whether the fact the only the first half of the carbon accounting regulations have been approved by Cabinet (the emissions part was done this week, the drafting of removals part isn’t finished) will delay matters. It’s my understanding that the Carbon Budget will deal separately with the standard emissions sectors (transport, heating, ag, electricity) and the “removals sector”, i.e. land use, so perhaps it doesn’t prevent the Council finalizing its proposal on the gross emissions side.

I have updated my Carbon Budget Calculator spreadsheet on that basis, and this is the resulting table.

There are a few things to note.

The headline number is the total carbon budget for the first two budget periods (i.e. the 10 year period 2021 to 2030). Of equal importance is how is that is broken down between the first Budget, 2021-25, and the second one, 2026 to 2030.

I have calculated two scenarios, based on the legal requirement in the Climate Act that emissions in the last year, 2030, are 51% lower than emissions in 2018.

In Scenario A, emissions go down 7% each year from 2022 to 2030. That’s the “linear 7%” scenario.

In Scenario B, emissions in 2021 and 2022 follow the current EPA projections and after that decline by 8% a year. This would be to allow for the fact that it will take a while for the new policies and measures in the forthcoming 2021 Climate Action Plan to have an impact. This is the “slow start / catch up” Scenario.

I have also included a “reference scenario”, which is the current EPA “with additional measures” scenario based on all the measures in the 2019 Climate Action Plan. That amounts to 539mt CO2e over the 10 years. And compares with a “no change” scenario (based on the 2019 emissions figures of around 60mt) of 600mt.

In Scenario A (linear 7%) the total 10 year budget is 432.4mt CO2e, the 2021-25 Budget being 255mt and the 2026-30 Budget being 177.4mt.

In Scenario B (slow start) the total 10 year budget is 448mt, the 2021-25 Budget being 268mt and the 2026-30 Budget being 180mt.

In the reference scenario the total 10 year budget would be 539mt, the 2021-25 Budget being 288mt and the 2026-30 Budget being 250mt. In a “no change” scenario each five year budget would be 300mt.

By the way, the only other Carbon Budget we have had was under the Kyoto Protocol, for 2008 to 2012 Ireland’s total allowable emissions were 314mt.