But I do want to share what might be the last couple rounds.
I do this for those interesting in dissecting science contrarian debate tactics and style, in the hope it might help inform some who are beginning to engage in the public climate science awareness dialogue (er, debate).
A reminder - this comes from the comments thread begun by MarathonS Feb 22, 2014 on the dubious YouTube video The PseudoScience of CO2 Based Climate where yet another coddled "old white guy" who knows nothing of climate science, feeds his audience what they want to hear.
Note - Dave and AL's words are unchanged, though I have corrected minor typos and made formatting changes including some highlights and of course I've also interjected a few comments and more links to educational sources.
It's difficult keeping the participants in this virtual dialogue separate, please bear with me - Dave's words are in Arial font, AL's comments are in purple, my additions are light green highlighted.
"Of course there is. Every ecosystem has an optimal CO2 level for that particular ecosystem" -
Why? based on what? how do you measure what is optimal?
There are numerous rainforests around the world, is one better than another? and which one of the dozens extant on the planet (do you) want to cater for? and what about the thousands of previous ecosystems? or the ecosystems to come? And how do you assess what is optimal for that ecosystem? What measurements do you use? And is this for earth now, in the past, or in the future? And why have you chosen a particular ecosystem as your determinant for optimal CO2 concentrations?
It is not that I do not know, it is absurd to declare that there is an intrinsic optimal CO2 level without first applying arbitrary, moralistic or desirous conditions upon that statement.
"But since you now have admitted that you don’t know what that level is, why are you then promoting a certain level of CO2 when you lack that knowledge?" -
I haven't admitted that I don't know, I am stating positively that it doesn't exist based on knowledge. And I am not promoting any level of CO2 at all.
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Consider for a moment that before the industrial revolution our global climate system had its atmospheric CO2 "regulator" slowly fluctuating between about 180 ppm (parts per million) to 280 ppm. And I mean slowly, taking about five thousand of years to go from peak to trough (±100 ppm), with profound changes from ice ages to temperate periods.
Around 1850 this gaseous regulator was set at the prehistoric peak of ±280 ppm, but by 1995 this greenhouse gas regulator increased 80 clicks, up to 360 ppm. It has taken only twenty years to ratchet up another forty clicks and bust through 400 ppm, which is setting up the earth for a hothouse future.
This added atmospheric insulation warms our climate system. Simple undeniable physics! This warming then forces the troposphere to hold more moisture. (…)
The point is that human history and our complex society developed under a climate regime where that CO2 regulator was set below 300 ppm. Since 1850 we've jacked up that regulator to 400 ppm. Historically such a shift of ±100 ppm took more than 5,000 years, before swinging back to the other extreme - now humans have added another 100 ppm on top of that long lived rhythm.
Here's a challenge - If Global Warming Is a Hoax …
By Phil Plait
