2015 marks the 10-year anniversary of C40 Cities Climate Leadership Group. To celebrate these 10 Years of Results, we will be sharing our favorite lists of 10 throughout the year.

C40 is a data-driven organization – our mayors know firsthand that if you can’t measure it, you can’t manage it, and we adhere to that philosophy. Find some of our most important metrics below.

1. 70+ megacities 

Today, C40’s global network consists of 70 megacities, and chair Eduardo Paes is committed to expanding membership to include more cities particularly in China, India and across the Southern Hemisphere.

2. 500 million people

C40 represents more than half a billion urban citizens around the world, and this number is set to grow. By 2050, more than two-thirds of the world’s population is expected to live in cities.

3. 25% of global GDP

C40 cities wield enormous economic power – taken together, the economies of C40 cities account for one-fourth of global GDP. Across the world, we see that cities are the drivers of development, growth and investment, making them critical players on the path to a low carbon economy.

4. 8,068 climate actions

Cities are taking concrete action to reduce greenhouse gas emissions and climate risks across multiple sectors. As of 2014, C40 cities have together taken 8,068 climate actions, nearly doubling the number of actions in just two years.

5. 3 times more likely

When it comes to climate change, cities are 3 times more likely to take action if a goal or target has been established.

6. 98 percent of C40 membership

C40 cities take climate change seriously: 98% of cities report that climate change presents risks to their city. Because of this, cities understand the need to exchange best practices and prioritize climate risks to ensure their climate resilience.

7. 15 networks

C40 has 15 networks in 7 initiative areas that bring together small working groups of cities to address specific issues, like transit development or green growth.

8. 500 percent increase

When mayors share great ideas, they can accelerate the deployment of smart urban solutions across the world. Our data shows that, from 2011 to 2013, there was a 500 percent increase in C40 cities with cycle hire systems, as cities followed the examples set by Paris and others.

9. 2 degrees Celsius

Scientists from the Intergovernmental Panel on Climate Change (IPCC) agree that we must limit average temperature rise to 2 degrees Celsius in order to avoid the worst effects of climate change. Achieving this target will ultimately require agreement between countries, but cities are playing a crucial role in getting us on the right path.

10. 1 gigaton of CO2e by 2020

C40 cities are taking action that reduces global greenhouse gas emissions – together, C40 cities have already committed to reducing emissions by 1 gigaton of CO2e by 2020. Through the Compact of Mayors initiative, we expect to see cities making even greater commitments on the Road to Paris 2015. 

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