Operationalizing Climate Justice: A Proposal to Quantify and Repay Climate Debts

This article proposes a framework to operationalize the concept and norm of climate justice in regard to historical responsibility for carbon emissions. Using an equal per capita (EPC) approach and 1990 as the base year, it allocates carbon budgets across countries and calculates climate debts for those that exceeded their fair share of emissions. Most high-income countries have overspent their budgets based on fossil fuel and cement production emissions (EFOS). The United States, for instance, holds the largest climate debt – around US48 trillion by 2021 – having emitted about three times its allocated share. Including emissions from land use, land-use change, and forestry (ELUC) significantly alters the results for Brazil, Indonesia, and others with high levels of deforestation since 1990. In line with the Paris Agreement's spirit regarding emission targets, countries could repay their climate debts using sources of their choice. This article suggests – among other revenue sources – a tax on centimillionaires and a global minimum corporate tax as fair and operationalizable sources of revenue for climate debt repayments. These repayments should prioritize low-income countries, the poor in middle-income countries, and/or those in vulnerable situations as part of strategies to align climate action with global development goals.