Yes, again I mostly agree with you. But it does not reflect the whole story.
- We (humans) are adding significant amounts of CO2.
- The present RAPID increase is not cause by the permafrost melting, but by our release of CO2. And because of the warming that this causes, the permafrost melts and causes more CO2 to be released. Potentially causing a run away effect. Similar (but 180 degrees the other way..) to the run away freezing of the earth when it was completely covered in ice.
- The cycles from ice age to warm periods do cause CO2 to be released by permafrost. But events like volcanos (Very large eruption release CO2 and a lot of other stuff too..) and the consequent temperature changes obviously follow later. As a matter of fact, scientists had a lot of discussion about how the planet could possibly have gotten warm again when the entire planet was covered in ice. When the planet is covered in ice the whole planet is white and reflects too much light (heat) to allow the ice to ever melt. So there was something going on, because the ice has obviously melted. This eventual melt is attributed to Volcanos and the massive release of greenhouse gasses by these volcanos.
Having said that, I agree that I should have been a little bit more careful with the bolt statement that CO2 is always followed by temperature change and not the other way around. I will check this out in a little more detail and come back to you on this, but I gotta go to sleep now. Have to go to work in 5 hours mate.
Joey
In passing, I'm amazed that this device allows me to exchange thoughts with folks from around the world.
What caused "Snowball Earth"? I'm not satisfied with the idea that we just got cooler for no reason.
It seems more logical that there was some sort of massive and prolonged Milankovitch Type Orbital Event affecting our orbit OR a prolonged cooling period reducing the Sun's radiation to us.
Conversely, the END of "Snowball Earth" seems to be similar to the end of our repeating Ice Ages. there is no terrestrial event acting as the prime mover that ends an Ice Age. It is Orbital influences rising from the effects of other planets.
The Anthropogenic contribution to CO2 is pretty small as a percent, but the small contribution is said to "add up" thus changing the totals.
That said, though, the warming impact of CO2 is a diminishing factor in Climate Change. See the chart below. It's similar to many on the internet.
Regarding the warming impact of Volcanoes, in today's world, it doesn't exist. The particulates also spewed out diffuse the incoming Solar Radiation and negate the Greenhouse impact of the CO2.
By this measure alone, citing Volcanic eruptions as the prime mover to end Snowball Earth, seems to be counter intuitive. It fits well into the "CO2 is the prime Cause" thinking, but does not seem to be logical.
The soot from volcanoes may have settled on the snow and caused melting due to albedo. It's possible that had an impact.
As I often caution when I drift into scientific areas, though, NOT A SCIENTIST. However, I always ask this question: "If this is true, what else must.be true?"
<snip>
[FONT="][/FONT][h=1]The diminishing effect of increasing CO2 concentrations on global temperature[/h]<snip>