C&C, the UK Climate Act, CO2 & future global carbon constraint

Carbon budgeting consistent with 'Paris Agreement' is now increasingly widely supported.
The UK Government is likely to face a Judicial Review of their under-amibtion against the Climate Act and the Paris Agreement - in a nutshell like this,

All Country CREDIT DEBIT introduction


As we approach the 'event horizon' of irreversibility with climate change, its worth remembering . . .


After 19 years of GCI's seminal, sustained & ultimately successful international effort
establishing the non-ideological Contraction and Convergence (C&C) concept, including in 2000 the
UK's Royal Commission making C&C the key recommendation to the UK Government . . .

& after much work in Whitehall & Parliament & its Committees, the UK Climate Change Act became law in 2008 &
Adair Turner, then Chairman of the Climate Change Committee, confirmed that C&C is the basis of the UK Climate Act

"We have endorsed Contraction and Convergence; we didn't call it that - it became emotive for reasons I don't understand."

As Chairman of the Climate Change Committee Adair Turner had written to the Minister (Ed Milliband) saying: -

"we believe that it is difficult to imagine a global deal which allows the developed countries
to have emissions per capita in 2050 which are significantly above a sustainable global average."

He subsequently confirmed at the Energy and Climate Change committee hearing that: -

. . . if for reasons of urgency the overall contraction rate had to be accelerated,
the convergence rate rate would have to be accelerated relative to that . . .


GCI submited evidence to the first 'Carbon Budget Enquiry' of the UK House
of Commons Environmental Audit Committee (EAC) setting out why: -

  • the UK Climate Act is based on 'the right principle but applied at the wrong rates' because
  • by omitting feedbacks, the UK Met Office modelling of the source:sink function was gravely misleading

The UKMO agreed with GCI's definition of Sink-Efficiency but pushed back against criticsm of their
carbon budget scenario ('2016 3% Low'). This was the source of what became a substantial conflict.


Centering on RCP 2.6, UKMO gathered the feedback-free RCP scenarios to 'lead' preparations for IPCC AR5.
For reasons unexplained to this day, RCP scenarios for 1.5° C were removed at this time.

GCI started work on the 4-dimensional Carbon Budget Accounting Tool (CBAT). This heuristic modelling of
feedback-emissions/effects was partly to counterveil the UKMO's climate feedback-free RCP methodology.


The first version of CBAT was presented in evidence to the second EAC Enquiry in 2013.
This demonstrated why the dangers obscured by feedback-free RCP methodology were an issue of grave concern.


The final version of the CBAT 'user-chooser' animation was published online. It was well received
Sir David King described it as, "a beautiful piece of work." A description of CBAT by Plan-B was published thereafter.


GCI created web pages based on CBAT and the INDCs
These led on the image below which, with 'the three budgets for compliance with 1.5° to 2.0° C, became very widely used.

From this global carbon budgeting came the basis of a legal strategy.


Sir David King presented this analysis of future carbon budgets in relation to the INDCs under the Paris Agreement at the IEA.