308 cities from around the world reported their emissions and energy mix to CDP's climate change study. These cities are home to over 446 million people, accounting for 6% of the global population. The data reveals diverse energy mixes among cities, from some relying 100% on non-fossil fuels to others relying 100% on fossil fuels. Many cities see opportunities to transition to renewable energy and have set targets to increase their share of electricity from non-fossil fuel sources. Cities can significantly influence the energy sector and accelerate the global shift away from fossil fuels through innovation and collaboration.