I'll be looking into this on my own, as well, but I thought some people here might have particularly good insight into this topic. What are the effects of freezing temperatures (from 30 F to -30 F, mainly) on large urban areas? I'm talking specifically about the effects on skyscapers, bridges, and other large landmarks/monuments? How long would a large city (NYC, LA, etc.) be able to maintain its "form" in constant freezing temperatures? When would buildings be destroyed? Would it happen slowly or many at a certain point? Thanks in advance for the information.