Thank you for the new article, Pierre!
I found a couple of places in the article which I don't understand. In the article you write:
Here is the image:
where the pink arrow clearly points to a drop of methane concentration and not to increase.
Then you connect this methane increase to global temperatures drop which happened around the same time:
So unusual about this methane spike and the global temperature drop is the fact that increase of methane should have actually caused warming and not cooling because methane is a strong greenhouse gas, right? But how does it explain then the temperature drop at the same time (5200 BC)? Did you mean that it caused a short period of warming which in combination with increased wetness brought about more cloud formation and resulting cooling?
I found a couple of places in the article which I don't understand. In the article you write:
At the same date, one of the largest methane spikes over the past 12,000 years was recorded in the GRIP Greenland ice core, as indicated by the pink arrow, with an increase from 600 to 650 ppbv (part per billion per volume).
Here is the image:
where the pink arrow clearly points to a drop of methane concentration and not to increase.
Then you connect this methane increase to global temperatures drop which happened around the same time:
So far we have found one date, 5,200 BP, that shows the unusual conjunction between a methane spike and marked global temperature drops.
So unusual about this methane spike and the global temperature drop is the fact that increase of methane should have actually caused warming and not cooling because methane is a strong greenhouse gas, right? But how does it explain then the temperature drop at the same time (5200 BC)? Did you mean that it caused a short period of warming which in combination with increased wetness brought about more cloud formation and resulting cooling?