It is still possible to limit climate change to 1.5°C

Quantifying fair national shares of the remaining global carbon budget has proven challenging. Here, we propose an indicator – additional carbon liability – that quantifies the responsibility of countries to mitigate and remove CO ₂ while achieving their own goals. Taking into account carbon debts since 1990 and future claims based on individual countries' emission trajectories, the indicator uses the same cumulative per capita emissions approach to allocate responsibility for closing the mitigation gap between countries with a positive total excess carbon claim. The carbon budget is exceeded by 576 gigatons of fossil CO ₂ when warming is limited to below 1.5 °C (probability 50 %). The additional carbon liability is highest in the United States and China, and highest per capita in the United Arab Emirates and Russia. Assumptions about the carbon debt significantly affect the results in most countries. The ability to pay for this responsibility is difficult for Iran, Kazakhstan and several BRICS+ members, unlike the G7 members. (Thomas Hahn, Johannes Morfeldt, Ingo Fetzer, more at nature.com)