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A simple and fair emissions model accommodating the wide range of proposals could be key to global consensus on how to control emissions.



Global CO2 emissions are approaching an average of 5tepa per capita and continuing to rise on an unsustainable Business as Usual trajectory.

Although not explicitly stated, the IPCC AR5 emission scenarios appear to implicitly relate to global per capita emission scenarios (conversion based on UN population forecasts).


Of these emission scenarios, RCP 4.5 (mean global pre-industrial surface temperature rise of approx. 20C 2050; 2.50C 2100) appears to be the most credibly achievable.

This scenario is structured into 2 main phases:

a) stabilization of average per capita emissions below 5tepa (allowing some total emission growth as global population grows and stabilizes) in the short to medium term.

b) longer term decarbonisation to stabilize global temperature.

This profile appears to offer the advantages of limiting the scope of a short to medium term global agreement to emission stabilization and allowing agreements on major decarbonisation to be taken at a future stage with better knowledge, technology, (and hopefully from a more equitable basis).

A simple and fair agreement modelled on and structured to stabilize average per capita emissions below 5tepa could be shown by modelling to accommodate the range of conflicting proposals from main global players leading to an improved basis for global consensus.

Category of the Action

Integrated action plan for the world as a whole

What actions do you propose?

Development of a regional and global input-output model to test emission scenarios and demonstrate that differing and apparently conflicting concepts of global agreement can be integrated within the proposed simple model to achieve medium term per capita stabilization (as per IPCC AR5 RCP4.5).

The principles of the proposed model would be:-

  •    Each country would provide carbon accounts (production and consumption).
  •   Each country would be measured against the greater of their production or consumption (this would limit potential to “export” emissions).
  •   Countries with average per capita emissions below 5tepa would have an emissions cap of 5tepa but would be free to develop within this limit.
  •  Countries with average per capita emissions above 5tepa would have a commitment to reduce their emissions by a defined % reduction rate of their emissions above 5tepa.
  •  The defined % rate would be set based on forecast modelling, balancing the forecast increase in per capita increase in lower emitting countries.
  •  Development of a structure providing positive trade advantages for compliant countries



1)     Current global input/output models provide an existing basis for production and consumption accounts.

2)     Measuring consumption emissions will bring sector and country carbon intensities into focus.

3)     Since population growth is forecast to be higher in low emission countries its net effect will be to lower average per capita emissions.

4)     The agreement can be flexibly altered by changing the average per capita emissions target and the % reduction rate.

5)     Measurement against a simple per capita emission allows ready comparison of countries, their progress, but is easily applied to community or individual targets and could become a standard basis for quantifying impacts and benefits.

Key to adoption of a model for global agreement will be how it accommodates the desires of the major economic and population powers and provides a general fair system. Some caricatures of the conflicting desires are:

  1. Developed and industrialized countries with high per capita emissions (eg USA). USA favors a broad % based reduction program. Their high per capita starting emissions allow for significant % reduction with existing technology (this would be more challenging for countries with a lower starting point). The proposed model would provide a broad basis (including China) of standard % emission reduction, but mediated by the % being applied to per capita emissions above 5tepa.
  2. Developed countries with relatively high per capita consumption (eg Europe). Europe favors a less broad % production based reduction. The proposed model would increase their benchmark position based on their higher consumption figures but this would be mediated by reduction calculated on per capita emission above 5tepa. These countries would benefit from intensity reduction in exporting countries.
  3. China favors carbon intensity (CO2/$) reduction. From a high intensity starting point this allows them opportunity to retain high economic growth rates supported by intensity reduction. The proposed model mediated by per capita emissions above 5tepa would result in a relatively low reductions target for China allowing them to focus on stabilization by intensity reduction – this could benefit importing countries and investment in intensity reducing technology as a model for developing countries.
  4. Developing countries with per capita emissions substantially below 5tepa (eg India) believe that they have a right to use fossil fuels to develop their economies. The proposed model would allow them to do so, but with a cap and with consumption targets on developed countries preventing excessive emissions exports to developing countries. Consumption targets on developed countries would help develop low intensity production for export.

Where will these actions be taken?

Initial development of the scenario model would be undertaken at University of Edinburgh (Scotland).

The model could subsequently be open-source shared to be used by a range of modelling and research organisations.

Successful development and adoption of the model would lead to global application.

Who will take these actions?

Initial development of the model would be taken by the team members (father and daughter team). Modelling work carried out by daughter in the team (Masters Student in Carbon Management) encouraged by father (Industrial Chemical Engineer).

If successful, development of the model and concept would be undertaken by international modelling groups to generate international interest and consensus.

Ultimate adoption of an agreement would be taken at a global political level.

What are key benefits?

The proposed model is based on a very simple principle using the desired outcome (stabilization of per capita emissions below 5tepa) as the direct measurement of performance within the model. (This contrasts with an existing global target of 2oC, which does not link directly to emission scenarios or a basis to structure the allocation of emissions from).

Using a global/ regional input-output model allows a range of reduction scenarios (absolute % reduction, changes in intensity etc), production v consumption, population change to be modelled and compared with the proposed simple model.  This would be used to demonstrate that the simple model can satisfy everyone’s proposals.

Standard per capita emission targets are directly understandable, comparable and scalable. They are as applicable to communities and individuals as they are to countries. This could become the standard basis for communicating and understanding climate change impact. 

What are the proposal’s costs?

Initial establishment of the model would involve several months for graduate student work.

As a simple model (based on existing input-output data) it doesn’t require major funding.

Time line

Establishment of initial model could be carried out as part of team members Masters Dissertation Q2/Q3 2015.

As a simple model development lead times should be short.


As new members working on initial short timescale we haven’t as yet been able to carry out a detailed exercise of looking at integrating other proposals. We however believe that the resulting simple model and a sharable input-output model could find wide application with other projects.

We believe that structuring emissions targets to a per capita basis offers a simple basis for other proposals to then quantify, prioritize and communicate benefit.

How do these sub-proposals fit together?

The output of this project – a simple concept and global model (Matlab, Excel) could be used broadly by other projects.

Explanation of model inputs

The input-output model data would be constructed from Eora MRIO database (using MatLab) and would be configured on a regional basis with major contributing countries defined as regions establishing a baseline emissions scenario.

UN population data (medium fertility) would be used as the basis of region/ country population forecasts.

The input-output model would be used to test a range of scenarios to 2045 (IPCC AR5 RCP4.5 per capita emissions change point). A range of parameters including developing country emission growth rates, developed country emission reduction rates, sector carbon intensity improvements would be modelled with the objective of demonstrating that the simple proposed model with an assessed % reduction rate based on per capita emissions above 5tepa would enable per capita emissions stabilization below 5tepa whilst fitting with the range of reduction. It would additionally test that the spirit of the range of alternative reduction proposals would be satisfied by this model.

Crude indication of possible outcome for example countries / regions

Based on example 66% reduction on emissions above 5tepa per capita by 2045.


IPPC AR5 Reports Summary for Policymakers and International Cooperation: Agreements and Instruments

Eora MRIO database

UN population forecasts