A guest post from Aubrey Meyer of the Global Commons Institute
In the light of the positive attention to 'Contraction and Convergence' shown by the Gaian Economics blog, please may I introduce you to CBAT, the 'Carbon Budget Analysis Tool'.
For example, the analysis tool quickly shows the IPCC AR5 Contraction-to-Concentrations results as a result of the UK Climate Act (UKCA). This particular piece of analysis shows the emissions-budget-integral in the UK Climate Act is either: -
[a] twice too much (and that's without the feedbacks) or[b] just a third too much or[c] just right
This really gives one something to chew on over regarding IPCC's stated '1,000 Gt C' maximum for two degrees!
Its also interesting to see/play that combined that with contraction-convergence-rates CBAT Domain Two. CBAT Domain Two perhaps explains why the prescribed global convergence date of 2050 in the UKCA was so inflammatory at COP-15. The convergence to equality by 2050 in the UKCA was something of a fig-leaf and using CBAT D2 animation quickly shows that. Its quite an eye-opener i.e. convergence by the time 80% of the budget has been used up makes no real difference at all.
GCI has always modelled that convergence for any rate of global emissions contraction should be at a negotiated in the light of 'historic responsibilities'. Subject to the UNFCCC-compliance rates of Contraction and Concentrations in D1, the animation D2 clearly shows the maths sub-division of this.
The CBAT is open to consultation and amendment so please take some time to look at it and comment on it. So far some others have and said supportive things, which is encouraging which are available on our website.