Defining a safe operating space for humanity.
New approaches are needed to help humanity deal with climate change and other global environmental threats that lie ahead. In 2009, a group of 28 internationally renowned scientists proposed global biophysical boundaries that define a planetary 'safe operating space' within which humanity can continue to develop and thrive for generations to come.
The scientists identified and quantified a set of nine planetary boundaries, on the basis of current scientific understanding of the Earth System. Crossing these boundaries could generate abrupt or irreversible environmental changes. Respecting the boundaries reduces the risks to human society of crossing these thresholds.
The study emphasizes that the boundaries are strongly connected. Earth´s linked physical, geochemical and ecological processes mean that crossing one boundary may seriously threaten the ability to stay within safe levels of the others.
Their analysis suggests that three of these boundaries (climate change, loss of biological diversity and nitrogen input to the biosphere) may already have been transgressed. For another boundary, ozone depletion, human activities did pass the threshold, but a concerted international response has reversed the losses and reduced the risks.
Our research priorities now are to improve our understanding of the boundaries and of the ways that society can respond to them.