This concept is the result of a collaborative research approach among a large group of scientists based on decades of ongoing research. The work presents a graphic (and/or video) that indicates the degree to which the human population is pushing a number of environmental areas beyond their understood safe zones. The research shows that three of ten subsystems have been pushed beyond safe boundaries; not surprisingly, climate change appears among them. Less expected, however, biodiversity and nitrogen loading round out the top three.
(Johan Rockstrom: Let the environment guide our development, TED Talk)
The figure is an effective way to illustrate the critical areas of environmental degradation that are pushing biogeochemical thresholds toward threshold breaking points.
(CC Image of planetary boundaries being exceeded by Christian Leichsenring (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons)