The current volcano activity has spewed more “greenhouse gas” into the atmosphere that humans could if they tried hard for a hundred years. No amount of science or tech or taxpayers money can remove what has been added over the last year. Frankly it hasn’t made a bit of difference. In other words, it is a scam. Most know it is a scam, but they press on.
Many dormant volcanoes also continue to vent gasses. Mt Hood and Mt Ranier, for example. This has gone on for hundreds of millions of years. The biology of the Earth has taken care of all of it.