I thought I saw this info in "State of Fear", but couldn't find it when I went back to look. And perhaps it came from somewhere else. Could y'all check me on this and hopefully provide a cite so I can show others?

Ok, here goes. There is a CO2 level above which we will go into the "greenhouse effect". This is what everyone is complaining about "we must reduce our CO2 emissions to prevent global warming" blah blah blah.

However, IIRC there is a /minimum/ CO2 level below which life will not be sustainable on our planet. _And_ we are much closer to that minimum threshold than we are to the maximum threshold.

So -- does anybody recognize this? Did I imagine seeing this, or is it accurate? If so, can someone provide the actual threshold figures for the minimum and maximum CO2 levels referenced above, and the current levels? Can someone provide a cite for this minimum level information?

Thanks in advance,

-rmh

Hi rmhartman,

Welcome to our discussions! It's nice to see a new contributor.

You have an excellent question! Though we're not really allowed to discuss GW or CC, I did some searching and learned quite a bit; things I never thought about before. Did you find in your searching that elevated CO2 actually increases crop yields? (No real surprise there, right?)Apparently the increased temperatures are what cause yield decreases, over which CO2 has no bearing. But I really shouldn't say much more. And I didn't find the answer yet to your question. I think it would depend on where one lives on the planet, don't you? Here's a table to look at:

http://www.authorstream.com/Presentatio ... owerpoint/

Although CO2 is tied to AGW by the proponents of that theory, I really was not trying to start a GW discussion. I am mostly interested in finding out the lower limit of CO2 required for sustaining the biosphere. Unfortunately any mention of CO2 these days ends up being tied to AGW.

Sadly, we kinda killed SOF discussion on the old boards. Hopefully one day soon the Moderator will allow it again since there has been some developments since that time.

Wouldn't it be fun to list those who have retracted their statements (publicly? I don't know) and those who have most recently spoken out with their statements of candor and objectivity?