There are still small pockets of tribal societies today, a millenia ago large portion of Earth were basically tribal. The tribal society we saw at the beginning of the episode may not have been typical of the entire planet, a medieval Europe equivalent culture could have exist on the next continent.
Maybe if Voyager had stuck around a week longer, they would have ascended and brought them home. I loked the N-1 type spaceships. Perfect place for an escaped con to go. Where did our suspect go? He landed here, and died recently of a ripe old age.
True. I think running out of resources is a far greater threat than full scale nuclear war. The accelerated development spike you mention was possible because we finally figured out how to use the large quantities of fossil fuels available to power factories, cars and planes. Once it's all used up, who knows what will happen. Nuclear war to control the last coal deposits? Maybe, maybe not. Oh wait, I'm on a Star Trek forum. The future is bright, the future is bright....
We're still using fossil fuels because it's cheaper to employ them as a power source and for transportation than the alternatives. When fossil fuels actually begin to run out, the cost of using them will go up, when that cost exceeds the alternatives we will switch over. As far as coal is concerned, there is a shit load of coal in existence that is currently not being extracted owing to the high cost of simply getting at it, but it is there. Total coal reserves for America are estimated to be as high as three trillion metric tonnes, but over half of that is in north-western Alaska, very hard to get at.
You think that is not going to be a problem? Things getting ridiculously expensive? If we don't come up with something else soon, there will be no affordable alternative available. And switch over? To what? Every alternative "fuel" right now (electricity, hydrogen) has to be produced with fossil fuels and that's no solution. Dr. Doom and Gloom, Out.
Washington State (where I live) get 75% of it's electrical power from Hydro-electric dams, my city of Seattle get 88% from hydro. France get (iirc) 80% of her electricity from nuclear. In the year 2011, Brazil produced over 20 billion liters of ethanol from sugar and other bio sources.