Anthropogenic Global Warming

[Timmah!]

Yulegoat said:

z64dan said:

Yulegoat said:

Oregon Petition really has about 17 000 signatories, but according to a survey conducted by Scientific American, only about 200 climatologists (extrapolation) on the list agree with the statements these days: http://www.sciam.com/page.cfm?section=sidebar&articleID=0004F43C-DC1A-1C6E-84A9809EC588EF21

Yes, CO2 leads to faster plant growth rates, but it is also poisonous in large quantities, in addition to being a greenhouse gas. For example, if you're closed for a long enough time in an air-tight space, you don't die to the lack of oxygen, but to CO2 poisoning because CO2 replaces the oxygen in your blood. That's because the CO2 concentration goes up as you exhale it. We're basically doing the same to the environment with adding CO2 to atmosphere from outside of the natural cycle. There's only so much CO2 that the ecosystem can handle.

You mean like the 8,000 PPM when the dinosaurs were around? As opposed to the 380 PPM nowadays?

What I meant is that the ecosystem is not able to keep up with the increased CO2 levels by increasing CO2 draining biomass, that is, the buffers don't work forever. When the oceans and forests have used their buffering ability, the CO2 levels will start increasing a bit faster, just like in prehistoric times when the CO2 levels start rising about 800 years after the initiation of a warm period. Life of course survives in a form or another no matter how high we can raise the CO2 level, but humans couldn't handle 8000 ppm.

Yulegoat: We can't handle 8000ppm?!? Do you have sources? 380ppm is .38%, 8000ppm is .8%, CO2 concentration has noticeable effects above 1% (10000ppm) lethal dose (rapid asphyxiation) is somwhere between 7% & 8% (70000 to 80000ppm). Here's the chart...

Health effects of respiratory exposure to carbon dioxide
(Baxter, 2000; Faivre-Pierret and Le Guern, 1983 and refs therein; NIOSH, 1981).

Exposure limits (% in air)	Health Effects
2-3	Unnoticed at rest, but on exertion there may be marked shortness of breath
3	Breathing becomes noticeably deeper and more frequent at rest
3-5	Breathing rhythm accelerates. Repeated exposure provokes headaches
5	Breathing becomes extremely laboured, headaches, sweating and bounding pulse
7.5	Rapid breathing, increased heart rate, headaches, sweating, dizziness, shortness of breath, muscular weakness, loss of mental abilities, drowsiness, and ringing in the ears
8-15	Headache, vertigo, vomiting, loss of consciousness and possibly death if the patient is not immediately given oxygen
10	Respiratory distress develops rapidly with loss of consciousness in 10-15 minutes
15	Lethal concentration, exposure to levels above this are intolerable
25+	Convulsions occur and rapid loss of consciousness ensues after a few breaths. Death will occur if level is maintained.

Chart from http://www.esc.cam.ac.uk/ivhhn/guidelines/gas/co2.html 

Sources are always good.