Towards a net-zero world: remaining carbon budgets, mitigation pathways, zero emissions commitment, and implications for policy
Co-organized by BG8
Convener: Andrew MacDougall | Co-conveners: Katarzyna TokarskaECSECS, Joeri Rogelj, Kirsten Zickfeld

Remaining carbon budgets specify the maximum amount of CO2 that may be emitted while stabilizing warming at a particular level (such as the 1.5 °C target), and are thus of high interest to the public and policymakers. Estimates of the remaining carbon budget comes with associated uncertainties, which are accounted for with various methods. These uncertainties increase in relative terms as more ambitious targets are being considered, or as emission reductions continue to be delayed, making practical implementation of remaining carbon budgets challenging.

This session aims to further our understanding of the climate response under various emission scenarios, with particular interest in emission pathways entailing net-zero targets, with meeting various levels of warming. We invite contributions that use a variety of tools, including fully coupled Earth System Models, Integrated Assessment Models, or simple climate model emulators, that advance our knowledge of remaining carbon budgets and net-zero targets. .

We welcome studies exploring different aspects of climate change in response to future emissions. In addition to studies exploring carbon budgets and the TCRE framework, we welcome contributions on the zero emissions commitment, the governing mechanisms behind linearity of TCRE and its limitations, effects of different forcings and feedbacks (e.g. permafrost carbon feedback) and non-CO2 forcings (e.g. aerosols, and other non-CO2 greenhouse gases), estimates of the remaining carbon budget to reach a given temperature target (for example, the 1.5 °C warming level from the Paris Agreement), the role of pathway dependence and emission rate, the climate-carbon responses to different emission scenarios (e.g. SSP scenarios, idealized scenarios, or scenarios designed to reach net-zero emission level), and the behaviour of TCRE in response to artificial carbon dioxide removal from the atmosphere (i.e. CDR or negative emissions). Contributions from the fields of climate policy and economics focused on applications of carbon budgets and benefits of early mitigation are also encouraged.