Solutions to the climate crisis from the world’s leading cities

29. October 2019

The Cities100 report showcases ambitious and innovative action from 100 of the most forward-thinking and inclusive climate action projects worldwide.

This was the foreword of the 2019 edition of Cities100.

By Anne Hidalgo, Mayor of Paris & Chair of C40 and Jesper Nygård, CEO, Realdania.

In October 2018, the Intergovernmental Panel on Climate Change (IPCC) published its landmark ‘Special Report on Global Warming of 1.5°C’ and the global conversation on the climate crisis changed forever. The scientific evidence is indisputable. Keeping global heating below 1.5°C is the only hope that we have of preventing irreversible disruption of the global water cycle, severely impacting global food security, exacerbating global inequality, and putting the health of billions of people around the world at risk. All the evidence points to the same alarming conclusion: we are not on track.

The bottom line is: this generational battle against climate change is a moral imperative, an environmental emergency, and a massive economic opportunity. The ambition of the Paris Agreement, including the 1.5°C heating goal cannot be carried out without urgent, coordinated efforts by nation states. Yet, just a handful of countries have set emissions reduction targets that are consistent with keeping global heating below 1.5°C. In contrast, more than 100 cities around the world have now committed, through C40’s Deadline 2020 initiative, to peak their emissions by 2020, halve them by 2030 and reach zero emissions by 2050. Today, it is mayors of the world’s great cities that are the most active and committed champions of the Paris Agreement.

This is a fight we cannot afford to lose

Cities are on the front lines of climate change, feeling the impacts of record-breaking temperatures, rising sea levels, and climate related natural disasters. Mayors recognize that the actions they take today are key in securing a sustainable, prosperous and healthy future for their citizens, and all people on our shared planet. The first priority of a mayor is to protect their cities and their citizens. They can’t do that if the climate is in breakdown. Citizens need to know there will be a livable planet and a place for them in it.

We are seeing cities and mayors rise to the challenges of the climate crisis whilst also acknowledging that climate breakdown is inherently unfair. The most vulnerable members of society disproportionately feel the impacts of climate change, including low-income communities, minorities, our oldest and youngest citizens. That is why cities are inviting marginalized groups and local people to help co-create sustainability plans, policies, and projects. In recognizing that climate action and social justice must go hand in hand, cities are providing safe homes, creating dignified jobs, building green transport systems, and cleaning the air that all citizens breathe.

These actions are transforming the world’s urban centres, improving people’s lives whilst also ensuring cities continue to prosper. They are building a future based not on fear, but rooted in hope. The 2019 edition of Cities100 identifies the specific climate policies and projects setting the global standard for what action to deliver the 1.5°C global heating target looks like. The 100 solutions bear witness to the leadership of mayors in the global fight against climate change. Mayors can’t solve the climate crisis alone. Our work is only made possible with the collaboration, support and shared ambition of all those nations states, businesses and civil society groups that are committed to uphold the highest ambitions of the Paris Agreement.

This year’s Cities100 will feature an analysis of how cities are facing the challenges and opportunities that come with being at the forefront of climate action. The launch of Cities100 happened at the C40 World Mayors Summit. At the summit Mayors, youth activists, climate scientists, and business leaders met in Copenhagen to learn from their peers and take home the lessons of the 100 most innovative city solutions. But everyone can learn and get inspired from the 100 best solutions, presented in the online publication of Cities100 available here:


Congratulations to the mayors and citizens of every city featured in this report, for their leadership in creating the future we want.