Wasted space finds new purpose as China pledges to go carbon neutral

China's Shanghai Metro is the biggest metro system in the world - and one of the busiest. CNN's David Culver takes a look at how the...

China's Shanghai Metro is the biggest metro system in the world - and one of the busiest. CNN's David Culver takes a look at how the massive metro-rail system is preparing for a greener future.

https://ift.tt/eA8V8J