Contribution of countries and regions to present warming (“Brazilian proposal”)
During the negotiations on the Kyoto Protocol, Brazil proposed a methodology to base Annex I (industrialised) country contributions to emission reductions on their responsibilities for the global mean temperature increase realised. The proposal was not adopted, but referred to the Subsidiary Body on Scientific and Technical Advice (SBSTA) of the United Nations Framework Convention on Climate Change (UNFCCC) for consideration of its scientific and methodological aspects. In the meantime, Brazil has revised its methodology. Here both the original and revised methodologies are evaluated. The original methodology proposed was found to be scientifically incorrect. The revised Brazilian model represents a major improvement with respect to the original version but still contains a few shortcomings. These can all be improved by corrections or by importing techniques already available in other models.
Evaluation of original Brazilian proposalThe FAIR model (Framework to Assess International Regimes for burden sharing) was developed to compare the Brazilian approach with other options for international burden sharing. Burden-sharing criteria accounting for historical emissions and/or based on a per capita approach are favourable for developing countries, while inclusion of anthropogenic emissions of all greenhouse gases and land-use emissions is favourable for the industrialised countries. Using an indicator later in the cause-effect chain of climate change is favourable for developing countries. UNFCCC project 'Assessment of Contributions to Climate Change' ( FAIR analysis )The Brazilian proposal for sharing the burden of emissions reductions among Annex-I Parties is based on the relative effect of a country's emissions on the global-mean surface-air temperature. This paper presents calculations of these relative effects, analysing the influence of the time horizon of emissions and of including non-linearities in the global carbon cycle.
Ad hoc group for the modelling and assessment of contributions of climate change (MATCH): paper ‘Analysing countries’ contribution to climate change: scientific and policy-related choices’This paper evaluates the influence of different policy-related and scientific choices on the calculated regional contributions to global climate change (the “Brazilian Proposal”). Policy-related choices include the time period of emissions, the mix of greenhouse gases and different indicators of climate change impacts. The scientific choices include historical emissions and model representations of the climate system.
Policy application: Differentiating future commitments on the basis of countries' contributions to temperature increaseThis paper analyses the impact of scientific uncertainties and of different options in policy implementation (policy choices) on the contribution of countries’ historical emissions to indicators of historical responsibility for climate change. The influence of policy choices was found to be at least as large as the impact of the scientific uncertainties analysed here. Building on this, the paper then proceeds to explore the implications of applying the Brazilian Proposal as a climate regime for differentiation of future commitments on the global scale combined with an income threshold for participation of the non-Annex I regions. |
