A study of the world’s megacities, those with a population greater than 10 million people, highlights the difficulties in resource use facing developing and developed cities around the world. As of 2010, there were 27 megacities around the world, and it is likely there will be 10 more by 2020.

Developed cities, such as New York, Tokyo, and London will need to decrease material and energy use to reduce their environmental impact, while developing cities such as Dhaka (Bangladesh) and Kolkata (India) need to increase their populations access to electricity and running water.

The analysis also showed the impact political policies can have on resource use: New York City produces 1.49 tons of waste per capita, while London produces 0.32 tons per capita, most likely due to a municipal solid waste tax.

Original research paper published in PNAS on April 27, 2015.

Names and affiliations of selected authors

Christopher A. Kennedy, University of Toronto, Ontario