In the name of Science!
Hi Brendon,
Thanks for your e-mail. I'll send you a more detailed reponse later tonight or tomorrow. In the meantime, I've attached a pdf showing in perhaps more detail the timing of CO2 and temperature changes. I'm familiar with the other studies you found, but I am impressed that you've done this much background research and know how to go straight to the best sources. That's excellent.
Yes, science is about sound, evidence-based argumentation.
Thoughts of vegetative cycles (similar to the "breathing cycles" of the Earth in winter and summer) were most prominent as plant life tends to have more available land mass when out of an ice age and CO2 concentrations are higher.
***greenhouse gases are also released (CO2 increase) as high latitude permafrost melts at the end of an ice age (thawing leads to decay of previously frozen organic matter).
The problem with this theory is that while the catalyst for a return to the ice age would be present (the use of CO2 and output of Oxygen in Photosynthetic processes)
***The catalyst for the recent (last million years) ice ages is Milankovitch cycles. On longer timescales, ice ages are triggered mostly by tectonic events.
the original event to spark an actual increase in CO2 would have to be the death of much vegetative life as the temperature cools. The danger here lies in that one would think natural selection eventually favors plants which are more tolerant to temperature changes and I know hardly enough about floral extinctions to carry on with that line of thought.
***Ice ages and CO2 changes aren't sparked by dying plants but they are helped along by plants being less or more productive as temperatures and duration of growing seasons change.
connected to a climate-driven net transfer of carbon from the ocean to the atmosphere". This explanation seems to make more sense, but again I find myself lacking the knowledge to understand why or why not this may be viable.
***I'll take a look at it.
Dr. Herbert
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I'm on campus currently, so I will be more readily available to download the article you've attached a bit later tonight or tomorrow. Feel free to take as much time as you need getting back to me, I won't begrudge any delay (though your reply seems to have been relatively instantaneous).
"greenhouse gases are also released (CO2 increase) as high latitude permafrost melts at the end of an ice age (thawing leads to decay of previously frozen organic matter)."
I understand the process and know it to be well evidenced, but if this were the prominent factor in climate change, wouldn't we expect an exponential, unending increase in Green House gases? If GHGs heat the atmosphere to a degree which is speculated by many global warming theorists, this process would be self-sufficient once the thawing started. The trigger to return to an ice age would be the Milankovitch cycles then, as you say. Scientifically this would mean however, that the Earth's position relative to the sun (axial tilt, axial rotation and eccentricity) would play a larger role in Earth's atmospheric temperature than would GHGs. This, I imagine, is the part you mentioned we cannot change. Do you know of any studies that have been done to test the exact relevance of GHG concentration to temperature? Venus makes quite an interesting case.
I do not yet understand how Ice Ages are triggered by tectonic events. Would you mind giving a quick explanation? I should be able to fill in most of the details with previous geology knowledge.
-Brendon
Thanks for your e-mail. I'll send you a more detailed reponse later tonight or tomorrow. In the meantime, I've attached a pdf showing in perhaps more detail the timing of CO2 and temperature changes. I'm familiar with the other studies you found, but I am impressed that you've done this much background research and know how to go straight to the best sources. That's excellent.
Yes, science is about sound, evidence-based argumentation.
Thoughts of vegetative cycles (similar to the "breathing cycles" of the Earth in winter and summer) were most prominent as plant life tends to have more available land mass when out of an ice age and CO2 concentrations are higher.
***greenhouse gases are also released (CO2 increase) as high latitude permafrost melts at the end of an ice age (thawing leads to decay of previously frozen organic matter).
The problem with this theory is that while the catalyst for a return to the ice age would be present (the use of CO2 and output of Oxygen in Photosynthetic processes)
***The catalyst for the recent (last million years) ice ages is Milankovitch cycles. On longer timescales, ice ages are triggered mostly by tectonic events.
the original event to spark an actual increase in CO2 would have to be the death of much vegetative life as the temperature cools. The danger here lies in that one would think natural selection eventually favors plants which are more tolerant to temperature changes and I know hardly enough about floral extinctions to carry on with that line of thought.
***Ice ages and CO2 changes aren't sparked by dying plants but they are helped along by plants being less or more productive as temperatures and duration of growing seasons change.
connected to a climate-driven net transfer of carbon from the ocean to the atmosphere". This explanation seems to make more sense, but again I find myself lacking the knowledge to understand why or why not this may be viable.
***I'll take a look at it.
Dr. Herbert
--------------------------------------------------
I'm on campus currently, so I will be more readily available to download the article you've attached a bit later tonight or tomorrow. Feel free to take as much time as you need getting back to me, I won't begrudge any delay (though your reply seems to have been relatively instantaneous).
"greenhouse gases are also released (CO2 increase) as high latitude permafrost melts at the end of an ice age (thawing leads to decay of previously frozen organic matter)."
I understand the process and know it to be well evidenced, but if this were the prominent factor in climate change, wouldn't we expect an exponential, unending increase in Green House gases? If GHGs heat the atmosphere to a degree which is speculated by many global warming theorists, this process would be self-sufficient once the thawing started. The trigger to return to an ice age would be the Milankovitch cycles then, as you say. Scientifically this would mean however, that the Earth's position relative to the sun (axial tilt, axial rotation and eccentricity) would play a larger role in Earth's atmospheric temperature than would GHGs. This, I imagine, is the part you mentioned we cannot change. Do you know of any studies that have been done to test the exact relevance of GHG concentration to temperature? Venus makes quite an interesting case.
I do not yet understand how Ice Ages are triggered by tectonic events. Would you mind giving a quick explanation? I should be able to fill in most of the details with previous geology knowledge.
-Brendon