On the mountain an under-performer can keep the entire team from reaching the summit or worse be the cause of a serious injury.

FORBES: CENTURY 21's CEO Embarks On His Toughest Journey Yet

She praised the work of Mr Clegg and Mrs Spelman, as part of the European delegation, to prevent the summit reaching "abject failure".

BBC: Clegg laments outcome of Rio+20 summit

The key to it will be whether any political leader - Britain's or one of the other 26 - believes the political cost of this summit reaching a deal is greater than the cost of it failing.

BBC: He was first in. Will he be first out?

From one vlei, we notice tiny movements atop one of the distant dunes, the outlines of two climbers reaching a summit.

CNN: Romancing the dune in Namibia

In the days leading up to this Summit, it was starting to look as though the eurozone was reaching this point.

BBC: One step back from the abyss