Cities are currently both climate-culprit and climate-victim. They are already responsible for 70 percent of global energy-related greenhouse gas emissions and 65 percent of global energy demand; they could easily account for more than three-quarters of electricity use by 2030. Cities in emerging economies, where 95 percent of population growth to 2030 and beyond will occur, will account for the majority (70 percent) of global growth in energy use through 2030.
Investments in low-carbon city projects have significant benefits for urban and rural citizens alike. A research review found that the economic and social benefits of those investments, such a improvements in citizen health, jobs generated, poverty and inequality eliminated, were many times greater even than the $17 trillion value. As just one example, health benefits of improved heating and insulation can be more than 10 times the value of energy savings.
Source: Green Biz - https://www.greenbiz.com/article/3-steps-thriving-zero-carbon-cities