The document discusses transitions in the context of sustainable development from the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Working Group III. It notes that unless immediate deep emissions reductions occur across all sectors, limiting warming to 1.5°C will be impossible. Accelerating mitigation through transitions involves expediting the pace, quality, and scale of change. Transition decisions will have significant consequences for sustainable development. Ambitious mitigation pathways require large disruptive changes to economic structures and can strand fossil fuel infrastructure. Integrating sustainability into mitigation policies results in fewer trade-offs than narrow mitigation policies alone. There are also potential synergies between mitigation actions and achieving the UN Sustainable Development Goals.