This whole conversation, stimulating though it be, is overlooking one glaringly obvious and unfortunate fact: an advanced technological civilization like ours depends entirely on an effectively limitless source of cheap net energy to build and maintain its infrastructure, and to feed and maintain its ever growing population. It also needs an intact biosphere to provide food, water, and oxygen. Yet that ship has sailed: our fossil fuels—the only available source of energetically cheap net energy—are rapidly depleting and will never be renewed within any human time frame, and as they deplete, they require ever more energy to extract the remaining fossil reserves—energy no longer available to maintain or rebuild infrastructure. Meanwhile their carbon emissions are already causing runaway climatic feedback loops that will soon devastate agriculture and lead to mass starvation and unimaginable social breakdown worldwide—even if psychopathic strongmen like Kim Jong Un or Donald Trump don’t nuke it first!