You state that "Geothermal drilling operations at multiple sites have been implicated in causing earthquakes.", could you provide links to articles that elaborate on this. The link you included refers primarily to a single site where drilling was suspended blaming "geologic abnormalities particular to the formation underlying this well location." Mention is made of the Swiss Geysers project in which a series of immense underground explosions led to some people claiming they had triggered earthquakes (although they have yet to provide the evidence for this, I'm not saying it didn't happen just that I'm keeping an open mind for now).
Such things happen all the time in the mining and mineral extraction industries, it's one of the reasons that test bores are drilled before comitting to large scale operations.
If we allow global warming to continue unchecked then over half the world's population will be adversely affected. To date about a billion people have been so affected at a cost estimated to exceed 4 trillion dollars. This amount pales into insignificance when you consider that best estimates put the cost of dealing with the consequences of global warming at more than this every year by 2050 if nothing is done.
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Edit: Re your added comments.
Thanks for the link regarding the drilling in CA. When I have a bit more time I'll do some research, but as I said, for the time being I'm keeping an open mind.
Regarding the cost of global warming. The documents I have which put a dollar value on the cost are ones which need to be purchased - you may be able to find abstracts online but I doubt the full publication would be available.
However, the Stern report estimates a cost in terms of GDP. In the report Sir Nicholas (Stern) warns that the cost of not tackling climate change could rise to 20% of global GDP. According to the World Bank and the IMF the current global GDP is $61 trillion. In this respect the cost of global warming would be $12.2 trillion a year by the year 2100, thus making my figure of $4 trillion a year by 2050 somewhat on the conservative side.
There are several other reports citing similar figures but I chose to reference the Stern Report because Sir Nicholas is a highly respected and trusted economist. He's not a scientist and has remained completely impartial in respect of climate change. The full report can be obtained here http://www.hm-treasury.gov.uk/sternreview_index.htm