Planetary Boundaries: 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 the 21st century.
Global biophysical boundaries can define a ‘safe planetary operating space’ that will allow humanity to continue to develop and thrive for generations to come, a group of 28 internationally renowned scientists proposes. Drawing upon current scientific understanding of the Earth System, the scientists make a first attempt to identify and quantify a set of nine planetary boundaries. This new approach to sustainable development that is to help humanity to deal with climate change and other global environmental threats in the 21st century is conveyed in the current issue of the scientific journal Nature.
Researchers propose critical planetary boundaries, transgressing them could be catastrophic. But there is hope.
- The human pressure on the Earth System has reached a scale where abrupt global environmental change can no longer be excluded. To continue to live and operate safely, humanity has to stay away from critical ‘hard-wired´ thresholds in Earth´s environment, and respect the nature of planet’s climatic, geophysical, atmospheric and ecological processes, says lead author Johan Rockström, Director of the Stockholm Resilience Centre.
Nine boundaries were identified including 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.
NATURE: A safe operating space for humanity
Nature 461, 472-475 (24 September 2009) | doi:10.1038/461472a; Published online 23 September 2009
More:
Nature Special : http://www.nature.com/news/specials/planetaryboundaries/index.html
Potsdam Institute for Climate Impact Research: http://www.pik-potsdam.de/news/press-releases/planetary-boundaries-a-safe-operating-space-for-humanity
Jordens grænser er overskredet
Videnskaben har indtil nu fokuseret på at kortlægge skader på naturen og miljøet, men først efter at de er indtruffet.
Nu foreslår en gruppe på 28 internationalt kendte forskere, at vi skal bruge vores viden om jordsystemet til at identificere de ‘grænser’, som menneskeheden ikke bør overtræde. Går vi over grænsen, er der nemlig fare for voldsomme og uoprettelige ændringer i miljøet.
Det skal ses i lyset af, at Jorden gennem de seneste 10.000 år har oplevet en relativ stabil periode i forhold til tidligere, hvad angår klima- og miljøforandringer. Men siden den industrielle revolution tog sin begyndelse i 1760erne og frem til i dag, har kloden undergået forandringer med store konsekvenser for natur og miljø på grund af menneskelige aktiviteter. Det gælder f.eks. vores forbrug af fossile brændstoffer, de menneskeskabte ændringer i naturen, den kemiske forurening og det moderne landbrugs anvendelse af bl.a. kunstgødning, påpeger forskerne.
Deres initiativ til at dæmme op for skader på natur og miljø afspejler også en ny måde at opfatte kloden på. Frem for at betragte kloden som splittet op i forskellige systemer og videnskaber, tager de 28 forskere udgangspunkt i, at kloden er en helhed, et sammenhængende system, der opfører sig næsten som en organisme, f.eks. en menneskekrop.
http://www.videnskab.dk/composite-3021.htm
