I debate them on Youtube and other websites. I consistently prove them to be wrong. I refute their beliefs of infinite human technological progress. Eating them for breakfast is fun. It is like debating with theists. I also eat them for breakfast. These people are so easy to refute it isn't even funny. As long as you have the correct world view, then you can win debates easily and demolish your opponents. I demolish theists and cornucopians in debates being a non-theist and doomer myself.
Cornucopian and theist beliefs are just plain wrong. There is two sides of a debate, and only one side can be right. Cornucopian and theist beliefs are wrong...non-theism and doomerism is correct.