In its yearly awards ceremony, C40 Cities singled out megacities around the world which are leading the way in terms of combating climate change, often with innovative initiatives.
Climate action plans and inventories
The city's Climate Action Plan 2015 ultimately won it this category. Portland is currently on target to reduce its greenhouse gas emissions by 40% by 2030, and 80% by 2050. Currently, half of its citizens use public transport, walk, or cycle rather than using a car.
Earlier this month the mayors of 40 cities from around the world came together in Mexico City to talk about climate change. But they weren't just there to chinwag about one of the most serious issues facing our planet, they were there to share best practices.
From China to Brazil, France to Ethiopia, the megacities of the C40 network are working to reduce their greenhouse gas emissions. The City Climate Leadership Awards, which took place alongside the C40 Mayors Summit, chose the most innovative projects across 11 categories to give the list of winners above.
Take a look at some of the fantastic initiatives already in place around the world to combat climate change in some of its biggest cities.