"Gee-Gee" is a cute name for "global geophysical event". If Cumbre Vieja erupted today, the resulting tsunami would wipe out about 100 million people, and destroy many US coastal cities. This is not new. I read about this a couple of years ago, and Dyer wrote this piece last August. It's been resurrected because of the Sumatra tsunami.
Problem is, we don't know when this will happen. Maybe tomorrow, maybe in 10,000 years. We don't have the technology to handle this type of disaster; although we do have the technology to perhaps mitigate Sumatra-style disasters.
In medicine we're taught not to seek data that we don't know what to do with -- it usually causes anguish without an upside. This is the same problem on a much larger scale.
It may make sense to sit on this problem for a few decades. We're not going to forget about it. We will face huge challenges in the next 50 years, if we survive those with an intact civilization, then Cumbre Vieja may be a relatively trivial problem.