It was almost painful to watch his testimony to the court - selective, speculative, and clearly loyal to the prosecution - being picked apart by a highly paid defence lawyer until the detective was forced to concede that all his bold assumptions about Oscar Pistorius's guilt were, on the current evidence, unsustainable.

BBC: Oscar Pistorius: South Africa police under spotlight

First, in recent years, we've seen a surge in climate and extreme weather events, along with analysis and other evidence that the world is on an unsustainable course.

CNN: More voices needed in climate debate

Solid evidence is mounting that much of this deterioration is the result of current (and past) unsustainable agricultural practices which, in the short run, have prevented food shortages.

ECONOMIST: Letters