She was a co-author of a series of high profile papers on planetary boundaries and Earth system governance.

An aim of this research is to work out if there are planetary boundaries and are we approaching them.

The 2009 study identified nine planetary boundaries and, drawing on current scientific understanding, the researchers proposed quantifications for seven of them.

The environment advisor Steve Bass says the "description of planetary boundaries is a sound idea.

However, a given planetary boundary may interact in a manner that changes the safe operating level of other boundaries.

Such considerations suggest the need for "extreme caution in approaching or transgressing any individual planetary boundaries."

Includes opinion essays by invited experts on the planetary boundaries.

In, 21 April 2011 - the term "planetary boundaries" is starting to shape debates, such as this one.

Maybe you should read Mark Lynas's book on planetary boundaries.

Take away one of their behavioral crutcheslike coffeeand we'll have violence feeding on itself, breaking planetary and station boundaries until everything is chaos.