Increased Volcanism caused by climate change

Can climate change cause increased increased volcanic activity by shifting the dynamics of the earth's crust as weight redistribution due to melting of the ice sheets at the poles and thermal expansion of the oceans?

It is a question that I've wondered about since reading Hansen's work back in the 1980's and 1990's and realizing that there would be crustal deformations as the great glacial weight on Greenland moves to the oceans by melting, and as the Antarctic sheds huge ice sheets. During climate change there is also sea level rise that occurs as the ocean warms by thermal expansion. Now we learn that these shifts in mass distribution on the spinning earth actually cause measured shifts in polar motion. In the journal Science Advances April 2016, Surendra Adhikari and collaborators Climate-driven polar motion: 2003–2015 present data showing how the modest warming experienced to date has produced measurable deviations in the earth's axis and wobble. This work also validates the understanding and modeling of weight redistribution as the earth warms and sea level rises.

My hypothesis is that these shifts in both the spinning motion of the earth and the crustal deformations responding to the weight redistribution due to changes in the ocean water will be subtle but enough to stimulate volcanic activity especially in regions such as Greenland where the local geodynamics may be more concentrated but also along continental margins and where islands sit atop rifts. I do not expect that the modest shift recorded to date has produced this effect, but expect that as the changes become much more pronounced and the spin dynamics exert an effect on the viscous core and mantle significant volcanism will occur. This increased volcanic activity would release significant quantities of particulate matter and Sulfur Dioxide that have a fairly short term climate cooling effect. Mt. Pinatubo released nearly 20 million tons of sulfur dioxide with climate effects that were small, but persisted for decades. If the aggregate increase in volcanic activity is large enough, it could produce significant climate effects. Now since geomechanics typically have a time scale of decades to millions of years, it is doubtful that I will be around to see if the idea has merit but it may be possible to do some modeling in the near future that could suggest an answer.

At any rate, it looks as if humans will be loosing our huge coastal cities, marshes and will be shifting our occupied space if our civilization survives the conversion of productive agricultural and forest land to arid desert as this inexorable climate change evolves over the next few thousand years. How sad that it is largely caused by the greed of a few of the elite who squandered our best chance to moderate or avoid the change by adopting a new energy infrastructure. There is still time to moderate the change, but humanity still has not grasped the horror that approches if we "stay the course" of exhausting the earth's fossil carbon stores to power our "culture".

A civilization that survives this phase of civilization must shift to a sustainable energy economy before causing mass extinctions and agricultural disaster that destroys the very civilization that caused the climate change. Maybe a topic for a future blog.

Over the long term, volcanic activity exposes fresh rock, sometimes in vast lava flows. When these flows are of the order that occurs when tectonic plates push over one another, the amount of fresh rock that then begins to weather and sequester CO2 can have a cooling influence on the climate. Unfortunately for our civilization, this process usually takes millions or tens of millions of years to have much effect....