In Beijing, the level of air pollution is the highest the monitors at the U.S. embassy have ever recorded since put in place in 2008. The pollution results from a combination of weather conditions and particulate matter - most from coal burning.
The good news is that we've survived yet another doomsday prophecy. Bad news - there's plenty more reasons to think our world is under threat. Vanessa Quirk looks at architectural responses to the threat - real or imagined - of apocalypse.