Friday 1 January 2010

Same world, poor world

Want our world to stay the same? Then its time to change the way we live.

For 10,000 years the world has been in a stable state which has enabled the growth of humanity.

But now we are breaking this by our activities - one of the most talked about is global warming or climate change, for which we are responsible.

Our actions have now become the main driver of global environmental change.

Environmental changes which previously occurred naturally and stayed within the earth's ability to regulate the effects, are being exceeded. In the past temperatures, freshwater availability and bio-geo-chemical flows stayed in a narrow range. Now, due to over consumption of fossil fuels, population explosion and industrial agriculture we are about to damage the planet.

We are consuming nature's resources and creating emissions 44% faster than nature can regenerate and reabsorb the waste. It takes the earth 18 months to produce the ecological services that we need in ONE year. We cannot continue to have "growth" based on our current life style.

The result will be irreversible! With abrupt environmental change, leading to a cessation of human development. This is science not politics.

Limits

What are our "Planetary Boundaries" or safe operating spaces? Most are defined by critical variables, like the concentration of CO2 int he atmosphere.

461472a-f1.2.jpg


Green is the safe operating space

Red is our current position

NUMBERS

Here are the numbers, pre-industrial and current (& proposed limit)

CO2 280 -> 387 ppm (350)

Forcing 0 -> 1.5 Wm2 (1)

Biodiv 1 -> >100 species extinct/10M/yr (10)

Ncyc 0 -> 121 Mt/yr N removed from air for our use (35)

Pcyc -1 -> 9 Mt/yr flowing into seas (11)

Ozone 290 -> 283 depletion (276, goes down)

Acid sea 3.4 -> 2.9 (2.5, goes down)

Water use415 -> 2600 km3/yr (4000)

Land use Low -> 11.7 (15) % cropland

Aerosols tbd

Polution tbd

As you can see the boundaries for 3 systems - biodiversity loss, climate change and human interference with the nitrogen cycle - have already been exceeded. Why?

1. Climate change by over use of fossil fuels as our primary energy source

2. Biodiversity loss by increasing world population and resource exploitation, driving other species to extinction.

3. Nitrogen cycle due to over intensive, fertiliser use in farming.

Full article at Nature September 2009

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