Cities have a role to play in driving action towards decarbonization. In Japan, as of August 2021, 444 local authorities have declared their intention to decarbonize by 2050, and it is important to know how to achieve this goal by drawing up a roadmap, developing specific measures, and ensuring their implementation. At the ISAP2021, session of “Zero Carbon Cities – What was said at COP26 and how will we move forward” held on 3 December, Mr. Togo Uchida, Executive Director of ICLEI Japan, and other speakers who participated in the United Climate Change Conference (COP26) held in Glasgow, UK, reviewed the discussions at COP26 from the perspective of cities, and discussed how to achieve zero-carbon cities and what actions should be taken to achieve the goal.