What's more, even without this embargo the era of cheap energy was largely over by the mid 60s, as oil's Energy Return on Investment fell to a fraction of what

What's more, even without this embargo the era of cheap energy was largely over by the mid 60s, as oil's Energy Return on Investment fell to a fraction of what it used to be: https://www.mdpi.com/sustainability/sustainability-03-01866/article_deploy/html/images/sustainability-03-01866f1-1024.png https://www.mdpi.com/sustainability/sustainability-03-01866/...