Climate proposal overestimates industrialised countries contribution to C02 increases

The so-called Brazilian proposal, which was first put forward during the Kyoto Protocol negotiations in 1997, links the contributions made by OECD and Central and Eastern European countries (Annex I countries) to emission control to Annex I country contributions to global warming. In this way, historical emissions would be included in determining the distribution of the burden of emission control.

The Brazilian methodology was not adopted at Kyoto, but the Third Conference of the Parties (COP3) decided to look into the scientific and methodological aspects of the proposal. The National Research Programme on Global Air Pollution and Climate Change initiated a study on the proposal prior to its discussion in the Council of the Parties’ Subsidiary Body on Scientific and Technical Advice (SBSTA).

The objectives were to evaluate the proposal’s scientific quality; to indicate possible methodological improvements; and to explore the Brazilian perspective on contributions to temperature increase as a basis for global burden sharing.

The SBSTA study – The Brazilian Proposal and other Options for International Burden Sharing: an evaluation of methodological and policy aspects using the FAIR model – evaluated both original and revised versions of the proposal’s methodology. The study found the original methodology of the Brazilian proposal used to illustrate the burden sharing approach was scientifically incorrect, resulting in an overestimation of the contribution of the Annex I countries to both CO2 concentrations and temperature increase.

The study criticised the Proposal for suggesting that there is a long time delay between the contribution to CO2 concentrations and temperature increase, adding that most other models show that CO2 contributions lead to temperature increases within a few years. The analysis should also have included anthropogenic emissions of CH4 and N2O, as well as CO2 emissions from land use changes, the study found.

While the study considers the revised Brazilian model an improvement, it also results in an overestimation of the contribution of Annex 1 countries to temperature increases. This, the study says, is because the revised version still ignores the terrestrial part of the carbon cycle and only focuses on oceanic carbon dynamics. The study says deficiencies in the revised proposal can be improved by corrections or by importing techniques and processes from other models.

The study also presents some explorative results from a new simulation model, called FAIR (Framework to Assess International Regimes for burden sharing). This model can be used to explore various alternative options for international burden sharing, including the Brazilian approach, and to combine these with various global emissions constraints.

Within FAIR, the Brazilian approach is implemented on a global scale and not just at the Annex 1 level, as in the Brazilian proposal. Using the model, the study found that burden sharing approaches accounting for historical emissions and/or based on a per capita approach are the right approach for developing countries, while inclusion of anthropogenic emissions of all greenhouse gases and land use emissions is favourable for the industrialised countries.

FAIR also includes a global application of a sector oriented burden sharing approach – the Triptych approach. Triptych assumes bottom-up improvements in energy efficiency and de-carbonisation of the power and industrial sectors as well as international convergence of per capita emission allowances in domestic sectors. This is in contrast to the top-down emission target approach.

The study found that if applied at a global level, the Triptych approach still leads to CO2 increases due to the strong growth in non-Annex 1 emissions, especially in the industrial sector. The study suggests global emission reductions could be achieved under this approach if improvement of sectoral energy efficiency in industrialised regions is combined with the transfer of energy efficient technology to developing countries.

“International burden sharing based on differential sectoral targets seems to offer an interesting alternative to top-down emission target approaches,” the study concludes, “because it takes account of differences in natural resource endowment and preferences, and problems related to internationally competing industries.”