There was a TV programme on BBC4 - still chance to chatch it in iPLayer.
They came up with the notion that the New Scientist has propounded for over a decade.

Melting icesheets "unload" (correct jargon) the mantle which is freer to move from the pressure beneath. More volcanoes over a shorter timespan. Prediction with conviction!

Global warming (howsoever caused) makes for more eruptions.
The only saving grace is that as each flight ban comes into effect it delays the effects of one of the most recent causes. By a miniscule amount, sadly.

And history should tells us (if there was anybody listening) that the nearby volcano of Askja has been shaken and will be a bigger show if (and it will someday soon) it goes off. see Wikipedia