Cement. Yes, cement

So I ordered Spotter's Guide to Urban Engineering for our library. It has a double-page spread on all sorts of civil engineering infrastructure: bridges, canals, bike lanes, water towers, pipelines, etc. It begins, however, with a brief overview of materials. This is where my last night's journey began.

First the provocative statement that cement is "the world's second most consumed substance." I didn't chase that one down, but it is a huge industry and telling economic indicator (check out the ballooning production in India and China, USGS).  The industry is also responsible for about 5% of global carbon dioxide emissions. That's because to create cement (and the world created over 3,000,000,000 tons of it in 2009, USGS  [the USS Nimitz weight in at 100,000 tons]) the ingredients are "cooked" at 2700 ° F in "the world's largest piece of moving inductrial equipment:" a rotating 700 foot kiln. Yikes!



Cement. It's what I learned about last night.