In 2009, Rockström et al published a paper in Nature which proposed the concept of nine planetary boundaries, which we must keep within if we are not to suffer potentially catastrophic consequences. More recently Nature has published an interesting opinion piece on the boundaries idea.
The space within these boundaries comprises humanity’s ‘safe operating space.’ You can find FCRN’s coverage of the original planetary boundaries work here and a link to the article itself in Nature here.
The author, Simon Lewis argues that while “conceptually brilliant and politically seductive” the boundaries concept has two important flaws. One is that some of the thresholds are in fact ‘fixed limits’ (and in terms of doing something about the problem, it is important to distinguish between the two); and the second is that some of problems defined as ‘global’ tend to have local or regional rather than global impacts (eg. nitrogen pollution). Lewis argues that focusing on them as global rather than local or regional problems could weaken overall political will.
You can read the article here.