Great collapse 

An event that some people think will happen in the future where all or most of civilization will collapse because of over population, useing up of resorces, deforestation ect.
In history a lot of civilizations collapsed at there high point instead of a low point as would be thought.

Did you hear that some people think there is going to be a great collapse?

Great collapse by Deep Blue 2012 August 18, 2009