Incorporating social indicators for an equitable carbon budget allocation among different geographical regions

Abstract As the global temperature continues to rise each year, limiting global warming to 1.5 °C is increasingly becoming a challenge due to the shrinking size of the remaining carbon budget. Under the Paris Agreement, countries committed to reducing their emissions based on national circumstances and priorities. Current emission reduction approaches account for past emissions, per capita emissions, ability to pay for mitigation, and other factors. Based on these factors, researchers have recommended various ways, such as the blended approach, for allocating the remaining carbon budget. However, it does not fully account for the social conditions that play a vital role in allocating the remaining carbon budget. In response, this research formulates a way to equitably allocate the remaining carbon budget among different geographical regions based on their social conditions. It incorporates critical social indicators based on the Doughnut framework to the Contraction and Convergence (C&C) principle, a commonly used allocation mechanism in climate policy, to determine equitable carbon budget shares at the national and regional levels. The share is obtained based on the proportion of current emissions associated with social performance and the proportion of the present population for 158 countries, which are grouped into 12 geographical regions. According to the equitable allocation mechanism, regions with poor social scores are assigned greater carbon budgets and vice versa. That is, countries and regions experiencing large shortfalls in their social foundation (e.g., frequent food famine) are allowed to burn more CO 2 to enable food security and rapid industrialization. Thus, this study addresses the challenges of addressing equity issues in carbon emission reduction necessary to achieve the temperature targets outlined in the Paris Agreement by introducing a robust method to account for a country’s socio-economic circumstances for an equitable allocation of the remaining carbon budget. Moreover, it establishes a reasonable benchmark for regional decision-making on climate action for countries vulnerable to climate change.