Who is responsible for overshooting the 1.5°C climate limit?

What is a fair way forward after the 1.5°C warming limit of the Paris Agreement has been breached? Co-authors on a new study recently published in PNAS, Chris Smith and Wim Thiery explored the concept of ‘net-zero carbon debt’ — a measure for assessing who bears greater responsibility for minimizing the climate overshoot. Using this measure, regions of the world bearing greater responsibility for the climate overshoot can be tracked through time, while explicitly accounting for past inaction. If a region is expected to accumulate net-zero carbon debt, it will need to compensate — either by supporting emissions reductions elsewhere in the world or by removing additional carbon from the atmosphere.

To highlight the implications of carbon debt accumulation, carbon drawdown obligations was assessed with respect to changes in lifetime exposure to extreme heatwaves under current global climate ambitions, building upon an earlier study of the group. “Our results show that every ton of net-zero carbon debt will not only increase the burden of emission reduction (and removal) on younger generations, but also worsen the climate impacts they will have to endure due to their region’s excess emissions”, says Wim Thiery.

Full press release on VUB news