Economist Steve Keen expects climate change to wreck civilization within decades, and blames his own profession for talking the world out of acting — a bleak call that clashes head-on with a new US government report.

• Keen says he would not have children today and tells young men to learn to hunt.
• He calls the new Department of Energy report downplaying climate risk nonsense.
• His main target is Nobel winner William Nordhaus, whose early math said big warming would barely dent the economy.
• The gap is huge: economists guess extreme warming shaves a quarter off output, while scientists say that much warming could end human life.
• He still wants a Star Trek future — moving production off-planet — and thinks Elon Musk wasted years on politics instead of Mars.

Outlook: The fight over whether climate damage is small or existential now runs straight through US energy policy, with the new report open for public comment.