Mackey Defends C&C
Here is a strong defence of ‘the three questions that C&C raises and
answers’ from Prof Brendan Mackey [ANU].
It is in response to an invitation from NCDO to support the Tallberg
Foundation [TF] call and search for ‘Plan C’ – a Global Deal on Climate
Change.
‘Plan C’ this is prompted by James Hansen’s new call for 350 ppmv. TF
has launched as ‘an international appeal’ to support this call for a
return atmospheric CO2 concentration to 350 ppmv
As Mackey points out the three questions that C&C deals with, and that
Plan C doesn’t yet, are: -
[1] what is the atmospheric ppmv value for CO2 we’re aiming at
[2] what it the path-integral of emissions consistent with that value,
and
[3] what rate of convergence to equal per capita sharing of that
integral is achievable.
The maths are as follows: -
350 ppmv 746 GTC 1988 200? [Hansen]
353 ppmv 752 GTC 1990
359 ppmv 765 GTC 1994
385 ppmv 820 GTC 2007
450 ppmv 959 GTC 200?
[1] in 1990 atmospheric CO2 in ppmv were 354 [i.e. 752 gigatonnes
carbon];
IPCC then said that immediate 60-80% cuts in CO2 emissions globally were
needed to get there.
[2] in 1994 ppmv were 359 [i.e. 765 gigatonnes carbon];
IPCC then said zero emissions globally by 2050 with negative emissions
thereafter were needed to get there; [this was deemed ‘impossible’ by
IPCC and the scenario was thereafter dropped];
[3] in 2007 ppmv were 385 [i.e. 820 gigatonnes carbon];
IPCC said that – with feedbacks better understood - zero emissions
globally by c. 2050 would keep us at and below 450 ppmv
So Jim Hansen’s call for 350 ppmv asap is a truly big-ask as he now
recognises [correctly] that the sinks are starting to pack up. Combined
with a 350 goal, this means negative emissions globally as near
immediately as possible . . . .
. . . . which rather side-steps, or was it avoids, the global
development deficiti and the politics of the existing infra-structure .
. . . and also rather explains why he is calling for the coal-fired
power stations to be bull-dozed [that’s one whole lot of bull-dozers but
I guess its fine if he can get them and get it done . . . ] . . . .
All the numeric modelling of this on which Mackey’s stand is based is
at: -
http://www.gci.org.uk/Animatio
