Global carbon budget allocation based on Rawlsian Justice by means of the Sustainable Development Goals Index

Despite the efforts to mitigate the effects and adapt to the global warming, the inequality in sharing of carbon emissions benefits and costs among the world population has given rise to the “Climate Justice” concerns which currently remain as an unresolved issue. It is expected that this issue may significantly be improved by deploying the Justice-based allocation of carbon budget between countries. Aside from this budget, the remaining budget is limited by mitigation scenarios. In recent decades, some egalitarian, responsibility-based, right-based and capability-based approaches have been presented for carbon budget sharing, which in this study, some of their major deficiencies have been listed. These deficiencies help the politics and business having a stronger hand in international decision-making processes. Then, as a pure Justice-based effort for global carbon budget sharing, the extent to which countries have achieved sustainable development goals has been considered as the only yardstick for differences among the peoples in the world. It is noted that the costs imposed on countries have implicitly been considered. A statistical methodology based on the proximity to development levels of countries has been used, with countries being stratified into the “Developed” and the “Developing.” Furthermore, taking into account these strata and Climate Action of each country, in this article the Rawlsian theory of Justice has been applied to allocate carbon budget among countries. As a result, the fair carbon budget share (FCB) model has been introduced as a dynamic and forward-looking mechanism for determining the annual share of countries of the global carbon budget. The fair share of countries, resulting from the FCB model, has been calculated based upon the available statistical data. The results have shown significant differences between actual carbon emissions of countries and their fair share for years 2017 and 2018. Moreover, for comparison purposes, the FCB-derived shares had a significant difference with the shares provided by the egalitarian approach. Furthermore, as expected, it was observed that the FCB model does not provide a predetermined and foreseeable trend for countries’ shares. This removes the biasedness criticism (commonly shared in all other approaches) for FCB model. Without any adjustment to the FCB model, the fair share of 2017 showed a significant balance between countries in debt or in credit when compared with their actual greenhouse gas emissions, which is indicative of the FCB’s readiness to enter a market mechanism.