Just 25 cities globally are responsible for 52 percent of urban greenhouse gas emissions, according to a new study that highlights the role that cities must play in reaching the goals of the 2015 Paris Climate Agreement.

For the study, researchers gathered data on greenhouse gas emissions in 167 cities in 53 countries. They found that megacities in Asia, such as Shanghai and Tokyo, ranked among the biggest total emitters, while major cities in Europe, the United States and Australia tended to have larger per capita emissions. In several major Chinese cities, however, per capita emissions matched levels seen in developed countries. The findings were published in the journal Frontiers in Sustainable Cities.

Power generation, industry and transportation were the biggest sources of emissions. In one third of the cities, road transportation accounted for more than 30 percent of emissions. Railways, waterways and aviation, by contrast, accounted for less than 15 percent of total emissions.

Read more at: Yale Environment 360

The Yan'an East Road Interchange in Shanghai, China. (Photo Credit: Denys Nevozhai via Unsplash)