Thanks for the time Jantimot. There are two points i pick up from your post. I'd like to start with the second point first.
Volcanoes and CO2 I agree there is no doubt volcanic activity can cause CO2 increase in the atmosphere. The question, I infer from your post is this... Is the volcanic activity causing the increase in CO2 rather than human activity?
The answer to this is certainly no. We know roughly how much CO2 we have emitted and its less than has accumulated in the atmosphere, the rest has been largely soaked up by the oceans (acidification). The spike in atmospheric CO2 is consistent with human activity.
There is less water vapor at the poles, and also a greater reflection of the suns energy due to albedo effect. Therefore CO2 will have a greater impact at the poles... this is exactly what we are seeing. And as we loose ice we reduce the albedo effect and have more ocean surface for greater energy absorption. https://www.climate.gov/news-features/videos/explaining-why-climate-change-amplified-poles
How how do we prove CO2 is causing this change? A picture speaks 1000 words....
As CO2 levels have increased, the outgoing radiation observed by satellite has decreased in the wavelengths that correspond to CO2. The loss of energy detected in this area is a result of the IR heat from the earth be reflected back to earth (warming). Changes are also apparent at other wavelengths that correspond to other greenhouse gases.
So you don't need to theorize about IR at the oceans / atmosphere boundary. We can see from direct measurement what energy is leaving the planet... or this case.... whats not.
