Back to the simple life or on to a hightech civilization? An ethics evaluation gives a clear answer to the course that should be taken.
Regardless of what is considered to be short term and medium term here, without technology it is not possible to avoid a catastrophe like the one 65 million years ago. So all long term evaluations without technology are negative.
Only a hightech civilization can prevent a catastrophe like the one 65 million years ago, so all long term evaluations are positive.
Please note! Burning fossil fuel can not be reagrded as "high tech".