Ironically, ideas also "represent a public risk of global harm." Does that mean we should ban communication and education, just to be safe?

(1) Horizontal gene transfer has been going on since the formation of life. And while I can imagine some extreme scenarios where engineered GM could be dangerous (Engineering a virulent airborne ebola virus, for example), it's not clear moving a gene from one species of an apple to another species would lead to global catastrophe.

(2) The world is an intrinsically dangerous place. Isn't there a greater likelihood that some ornithologist goes to the Amazon and inadvertently brings bring back some new virus or bacteria? Given the heavy regulation, ethical considerations, regulatory testing, and precision involved in engineered-GM, this seems like a much greater danger to humanity. Should we halt international travel as well?

(3) Unlike GM where we have controls, regulations, and exhaustive testing, there is no such precautions for radioactive and chemical mutagenesis that make massive wholesale genetic changes to a genome. You could even argue that GM is safer than non-GMO methods.

Basic point, maybe he cannot prove that GMs are dangerous but no one can prove that they are safe.

So why risk things when there are other ways

I notice he cited Seralini (who claims GMOs cause cancer in rats). That's not a reliable reference.