Planetary boundaries is a new concept gaining increasing attention in the field of sustainable development. These are the biophysical boundaries humanity has to stay within to avoid catastrophic tipping points in climate and ecosystems.
Listen to Professor Johan Rockström of the Stockholm Resilience Centre when he introduces the Planetary Boundaries concept he has developed together with 27 other leading scientists.
A group of 28 leading scientists have worked for more than a year now to make a first attempt to identify and quantify a set of nine planetary boundaries. Keeping within these will act as a safety barrier for sustainable human development, according to the group of scientists in an article published in Nature, September 24.
The nine boundaries identified include climate change, stratospheric ozone, land use change, freshwater use, biological diversity, ocean acidification, nitrogen and phosphorus inputs to the biosphere and oceans, aerosol loading and chemical pollution.
The study suggests that three of these boundaries (climate change, biological diversity and nitrogen input to the biosphere) may already have been transgressed. In addition, it emphasizes that the boundaries are strongly connected – crossing one boundary may seriously threaten the ability to stay within safe levels of the others. In sum, humanity is beginning to push the planet out of its current stable Holocene state, the warm period that began about 10,000 years ago and during which agriculture and complex societies, including our own, have developed and flourished, say the scientists.
In addition, the planetary boundaries concept is already gaining interest outside the scientific community, and will be the subject of an upcoming book by environmental author Mark Lynas, whose previous climate change book “Six Degrees” won the Royal Society Prize in 2008.
Safe within boundaries The researchers stress that their approach does not offer a complete roadmap for sustainable development, but does provide an important element by identifying critical planetary boundaries. Within these boundaries, humanity has the flexibility to choose pathways for our future development and well-being.
In essence, they have begun drawing the first map of our planet’s safe operating zones. “Beyond the edges of the map, we don’t want to go”, says the group in a press release. Their future research will consider ways in which society can develop within these boundaries in a safe, sane and sustainable way.
Source: Rockström, J and 27 others. 2009. "A safe operating space for humanity". Nature, Vol 461, 24 September, pp. 472-475