Wednesday, September 10, 2008

Misplaced criticism of the Garnaut proposal

Amanda Lynch from Monash University's 'Climate Program' writes a 3/4 page op ed in The Age this morning criticising the Garnaut Review's draft report on 'Targets and Trajectories' for setting excessively high greenhouse gas emission targets of 450 ppm.  Unfortunately this claim seems wrong - Garnaut targeted 550 ppm and the criticisms she makes should relate to this target. Garnaut rejects the 450 ppm target as infeasibly low. For example, at 550 ppm, not 450 ppm as Amanda claims, there is only a 50% chance of restraining temperature rises to 2oC.

 I have criticised aspects of the Garnaut proposals - though as I reread his report my attitudes are softening somewhat - but it is important for Amanda to get her facts right.

The positive claim in the Garnaut argument that needs to be critically tested is the view that to cut emissions to 450 ppm would impose impractically huge cutbacks on developed countries given the expectation of continued high emissions growth in developing countries. That's the point where I become ambivalent. Is it better to target something modest but achieveable but which still carries the prospect of catastrophe or should we target something much less feasible which substantially reduces the prospect of catastrophic change?


Spiros said...

Cutting back to 450 would involve replacing all our coal fired power stations with something else within a couple of decades.

Realistically, Harry, how is that going to happen?

Nuclear is off the table and even if it got put on the table tomorrow, it is hugely expensive. The planning processes would also be formidable and prohibitive.

Large scale carbon capture and storage might happen in the future, but it might not either.

Renewables are OK (but expensive) for peaking and intermediate generation but not baseload.

hc said...

Spiros, the 450 ppm target discussed as a hypothetical by Garnaut was to be hit 2050 not 2020.

But I agree it's a big ask. On the other hand the 3oC warming likely with a 550 ppm target will cause big pain.

It is complex.

Spiros said...

As I understand it three degrees is the upper limit we (the world) could live with, albeit with significant adaptation. More than three degrees is when the really big problems kick in, such as massive species extinction, widespread crop failure and tropical disease spread

Of course 3 degrees is the world average and for Australia the science says it will be more and so a lot worse. Central Australia will become unliveable (temperatures up 8 degrees; don't buy any real estate in Alice Springs) and the Barrier Reef will die.

But if the world does a deal that limits the temperature to 3 degrees, there's not a lot we can do about it. We really might get screwed a lot of ways. We're not powerful enough to force really drastic cuts in emissions but physically we are very exposed to climate change.

That's my reading of Garnaut.

conrad said...

I guess a 550ppm target at least reduces the prospects of catastrophic risk. I also think in this case, part of the problem is in actually acting, and if it turns out that there isn't much of an effect of acting (which seems likely), it means others will be more likely to act too.