Crossing Planetary Boundaries

The Earth has nine biophysical thresholds beyond which it cannot be pushed without disastrous consequences, the authors of a new paper in the journal Nature report.

Ominously, these scientists say, we have already moved past three of these tipping points.

quotes...

They concluded that there was good evidence for nine kinds of thresholds: climate change, ocean acidity, the ozone layer, freshwater use, the movement of nitrogen and phosphorus, the amount of land used for crops, aerosols (haze and other particles), biodiversity, and chemical pollution.

and...

A lake, for example, can absorb a fair amount of phosphorus from fertilizer runoff without any sign of change. “You add a little, not much happens,” says Shahid Naeem of Columbia University, who was not involved in the Nature paper. “Add a little more, not much happens. Add a little... then, all of sudden, you add a little more and — boom! — phytoplankton bloom, oxygen depletion, fish die-off, smelliness. Remove the little phosphorus that caused the tipping of the system, and it does not reverse. In fact, you have to go back to much cleaner water than you would have imagined.”

the rest...

http://www.e360.yale.edu/content/feature.msp?id=2192

I suspect, with a little thought, you may be able to know which three tipping points we have crossed... carbon, nitrogen, and extinction rate.

of the other nine, I suspect we perhaps have passed the "ocean acidity" threshold too, however the ocean is not "acidic"; the pH has fallen substantially. We have also, IMO passed the threshold of chemical pollution, and are real close to others.

I do hope NO ONE here uses these things... or minimizes their use as much as practical.

Crossing these threshholds holds catastrophic consequences - very quickly... read the second quote again. In my college studies of ecology and organismal biology, we studied tipping points like over population in confined areas (earth is a confined area)... when the tipping point is close, nasty aggressive behavior increased, the system crashed, and the VAST majority of the mice died.

Is a global ecosystem crash what we are heading toward? It sure looks that way...

I do realize that there is debate and controversy about this, however, IMO, there is no time for debate; it will happen at some point if we continue our ways unabated, unless Science pulls a rabbit out of their hat yet again to buy us a little more time... but then, what will your kids or grandkids be faced with?

Cree proverb/prophecy: "Only after the last tree has been cut down, Only after the last river has been poisoned, Only after the last fish has been caught, Only then will you find that money cannot be eaten."

grz-