On 31/05/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> I'd guess that Griffin wants dangerous climate change avoided, but
> presumably his personal idea of where the threshold between dangerous
> and not dangerous lies differs from Hansen's (I don't entirely
> understand the organisational structure of NASA, is Griffin actually
> Hansen's line manager?).
I would like to know what Griffen would consider dangerous.
Consider the following:
1. According to the IPCC WG1 AR4, we are speaking of agricultural
output being cut in half for some countries.
2. The south west of the US is quite likely to enter a state of being
a permanent dustbowel.
3. Agricultural output in the south east US will be greatly reduced
due to drought.
4. NASA recently projected average temperatures from 100-110 F for
July-Aug during the drier years in places like Chicago and Washington
DC.
5. Hansen himself sees the potential for positive feedback between
the disintegration of glaciers in Greenland and the western penninsula
of the Antarctic.
6. With a ballooning world population and increased drought, we are
going to be faced with severe water shortages in the decades to come.
7. According to our best estimates, the Amazon river valley stands a
10-40% change of becoming a desert due to changes in weather patterns.
8. Fish harvests are going to be greatly reduced due to disruptions
of the food chain as the result of increased acidity of the ocean.
9. There is evidence that plants are already losing their ability to
absorb carbon dioxide due to increased heat stress.
10. Both the arctic and and antarctic oceans are losing their
capacity to absorb the carbon dioxide - and their capacity for
absorbtion will continue to decrease as temperatures rise.
11. Until recently the ocean was absorbing 80% of what we emit, but
in time it appears that it will become an emitter (although likely not
in this century).
12. The absorbtion of gas is principally by cold arctic water - but
temperatures rise much more quickly at the higher latitudes.
13. Rising temperatures will not only diminish the ability of the
ocean to absorb carbon dioxide, but oxygen. There exists the real
possibility that, in time, the ocean will become hypoxic - which has
been associated with mass extinctions both on land and in the sea in
the past, including "The Great Dying" 250 million years ago.
Something about exceeding 1000 ppm - although it would in all
likelihood take centuries and not be all at once.
14. Currently we are at about 384 ppm, but with the strong positive
feedback from the carbon cycle, models are projecting levels between
730 ppm and 1020 ppm by the end of the century.
*
Consider the economic impact of people displaced by rising ocean
levels - which are accelerating.
Consider the political impact of water and food shortages.
Consider the fact that the world climate has been unusually stable for
as long as human civilization has existed. An agrigarian society
would have in all likelihood been unable to evolve in a period of
climatological change.
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