Former Greenpeace campaigner Patrick Moore has, in recent years, constantly criticized the environmental movement.
He's even purported that there's no scientific proof that human beings are contributing to climate change by burning fossil fuels.
Recently he claimed that glyphosate, the active ingredient in Monsanto's herbicide Roundup, wasn't linked to cancer cases in Argentina.
It has also become a hot issue in Europe.
"You can drink a whole quart of it and it won't hurt you," Moore declared on French TV.
The interviewer then turned the tables by telling Moore that he had glyphosate in the studio.
"Would you like to drink it?" he asked.
Moore replied that he would be happy to do this before changing his mind and declining the offer.
"I know it won't hurt me," Moore quickly added.
The interviewer reiterated that he had some glyphosate.
"I'm not stupid," Moore said in an irritated tone.
When the interviewer persisted, Moore replied, "I'm not an idiot. Interview me about golden rice. That's what I'm talking about."
As Moore walked out of the studio, he could be heard saying, "You're a complete jerk."
(The video above describes Moore as a lobbyist for Monstanto but according to the company, he has never done any paid work for it.)