"What does this mean? That these staggeringly high numbers (if true) do not necessarily mean doom but "merely" that at some point people will find out that the pensions they have been promised won't be there when they reach retirement."

This is true. And since money, debt and energy are interlinked, it is very possible that there will be a cliff that we are approaching. Only two questions remain:

1. When?

2. How deep will we fall?

"There is No Steady State Economy (except at a very basic level)" http://ourfiniteworld.com/2011/02/21/there-is-no-steady-stat...

Limits to Growth–At our doorstep, but not recognized http://www.resilience.org/stories/2014-02-12/limits-to-growt...

Wealth And Energy Consumption Are Inseparable http://www.declineoftheempire.com/2012/01/wealth-and-energy-...

Galactic-Scale Energy http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e...