Author: Dominic Meagher

There seems to be considerable confusion about Garnaut’s recommendation as to what targets for emissions reduction the Australian government should set.

Garnaut is very particular in the way he articulates his recommendations. The media and public commentary has not been so particular.

There are two sets of targets: primary and secondary. The primary target is the global concentration of GHGs in the atmosphere. This target must (by its nature) be a global target agreed to by at least all of the major GHG emitting countries. The secondary target relates to emsissions reductions. The emission reduction target is a national action target. Each country would have their own emission reduction target. Meeting the global atmospheric GHG concentration target would require all countries to meet their respective emission reduction target.

1. Primary target: global atmospheric GHG concentration target (ZZZ ppm by 2050)
2. Secondary target: GHG emission reduction target (ZZ% reduction of Australia’s annual emissions from 2000 levels by 2020 and ZZ% by 2050)

The secondary target is conditional on the primary target.

If the primary target is strong, the secondary target must be strong also. If the primary (global) target is weak, a strong secondary (Australian) target would have scant benefit and significant cost to us.

Announcing before hand, that Australia will set a strong secondary target CONDITIONAL UPON global agreement on a strong primary target makes reaching a strong primary target more likely. Other countries know we will not free ride on their efforts.

Similarly, announcing ahead of time that we are prepared to set a moderate secondary target CONDITIONAL UPON global agreement on a moderate primary target (assuming a stronger target is politically impossible), makes moderate success more likely. It also makes a strong primary target more likely since other countries also know we will not let them free ride on our efforts.

This is why Garnaut says:

The Australian government should, at an early date, say that Australia was prepared to play its full proportionate part in a global agreement that adds up to a 450 ppm outcome.

If such an agreement is not possible internationally (and what is more likely to be possible internationally is a 550 ppm outcome) then we would be prepared to play our full proportionate part in a global mitigation effort that delivers a 550 ppm outcome.

Garnaut concludes that if the world agreed on an atmospheric GHG concentration target of 450 ppm by 2050, our fair role in achieving that target would be to reduce our annual emissions by 25% from their 2000 levels by 2020 and 90% from the 2000 level by 2050.

If the agreed upon primary target was 550 ppm by 2050, our full proportionate part in achieving that goal would be to reduce our emissions by 10% from 2000 levels by 2020 and by 80% from 2000 levels by 2050.

For reference, the relevant chapters of Garnaut’s report are:

7.     Australia’s emissions in a global context
8.     Assessing the international response
9.     Towards global agreement
10.   Deepening global collaboration
11.   Costing climate change and its avoidance
12.   Targets and trajectories

For a 680 page document, the Garnaut Review is remarkably easy to read. Anyone who feels obliged to comment on climate related issues should read it first.