In this particular case, the ideal gas law doesn’t hold, and rocks can indeed melt on decompression due to changes in the chemical potential of stable phases becoming unstable with subsequent dissolution back into the melt. That said, the theory this scientist is pushing is preposterous on the face of it, due to energy budget considerations, and known tectonic mechanisms.
I should learn to keep my stupid mouth shut. It has been at least 25 years since Chemistry.
Nonetheless, I thought the point of a pressure cooker was to allow higher temperatures?
In the case of the increase of volcanic activity at the end of the last ice age, it is possible that the outburst of volcanism in Europe WAS caused by the melting and lifting upward of compressed areas in Europe. There were significant volcanic eruptions or flows in Germany, France, and Italy. Activity has continued in Italy on a smaller scale.
However, the idea that global warming will trigger intense volcanic activity is a real stretch unless it might take place in Antarctica if great quantities of ice melt where Mt. Erebus and others are located, also allowing significant uplift. While melting may be taking place in the Alps, and the Himalayas, these are not volcanic type mountain areas. I don’t think there is deep enough snow cover to affect the volcanic potential in the Andes.
I have noted an interesting phenomena in the temperature charts. Between 30,000 and 22,000 years ago there were three major temperature drops. I have identified one possible cause for the drop 22,000 years ago. That is the eruption of Sakura-Jima. This Japanese volcano left a 15 mile diameter caldera which could have sent up a lot of ash and cooling sulfur. Currently there is an active smaller volcano on the edge of that caldera, as well as a city and port.