Recently, I showed that the subjectivist, post modernist, anti-truth position of the left is false, with numerous examples, in an argument peppered with literary and philosophical references, and ran into an ideologically indoctrinated brick wall of direct contradiction. This inability and/or unwillingness to learn plunged me into a sudden and deep depression, for - if humankind cannot learn, cannot correct this mistake, we are doomed. — counterpunch 
As some sort of leftist, I agree with you that a lot of the subjectivist, post-modernist, anti-truth, political correctness..." of the left is wrong, or sometimes not even wrong.  Some of it is just plain nonsensical.  I don't socialize much with people, especially the younger (or youngish) adults among whom there seems to be a lot of "leftist affect" (meaning, they sound like leftists but most likely are not).  The literary theory of post-modernism is the worst slop I have encountered in a life-time of reading.
As time passes, it seems like the terms "left" and "right" have become less meaningful.  It isn't that the continuum of opinion doesn't exist, but that the labels have been emptied of meaning by overuse.  Lots of words have been ruined by excessive use and abuse.
Magna Magma:  The only problem your idea of capturing energy from magma has is that the industry required for economic viability hasn't appeared.  In 1945 there was no industry in place for atomic energy.  It got built, but it took decades.  The same goes for steam-generated coal powered electricity.  The industry had to be developed over decades.  There are hot-spots here and there where geo-thermal heat is close, or relatively close to the surface.  Iceland; Yellowstone; various places on the pacific rim, etc.  Many other areas sit on thick cold rock, and we'd have to bore much deeper.
A couple of years ago a long-time TPF member proposed floating large arrays of solar cells off shore.  Sounded like a non-starter at the time, but I have since read of arrays that have been built, are floating, and producing electricity.
All the approaches that can be done; should be done, including the magna magma option.
You are not the only one running into brick walls.  As a sometimes-socialist-agitator I can appreciate your frustration with brick walls.  The very word "socialist" is a thought stopper for many people, a no-go zone.
About sustainability and consumption:  What environmentalists mean by "reduced consumption" isn't a fixed standardized thing. My own experience is that I can consume less 'stuff' without the slightest reduction in my standard of living.  Example:  reading books and newspaper in digital form rather than paper.  Drinking tap water instead of bottled water (which is often the 
same water one gets out of a tap).  Not replacing clothing that is in very good condition.  Keeping appliances until they fail.  I use mass transit because I do not drive, and for many purposes it works.  For some purposes it fails or doesn't exist anymore.  Granted, it doesn't work for many people because of past huge investments in auto transportation coupled with long-term 
DISinvestment in mass transit.
Given the huge quantity of CO2 that transportation contributes to the atmosphere, that is one of the areas where 'green' will mean changes that will feel like loss to maybe a billion drivers.