China used more concrete in 3 years than the US in 100 years

Bill Gates has an incredible statistic: According the USGS' cement statistics, China has used more concrete from 2011 to 2013 (6.6 gigatons) than the United States in the entire 20th century (4.5 gigatons). It blows my mind but, then again, as Gates point out, look at Shanghai's evolution in just 20 years... » 2/23/15 6:00am Monday 6:00am