Musk and more than 1,000 artificial intelligence experts and industry executives signed a joint letter calling for a moratorium on the training of artificial intelligence systems stronger than GPT-4 for at least six months on the grounds that such systems pose potential risks to society and humans. "Powerful artificial intelligence systems should only be developed if we are confident that their effects are positive and the risks are manageable," the letter reads. Musk has expressed concerns about artificial intelligence several times before. In a video speech in February this year, he stated that artificial intelligence is one of the greatest risks to human civilization in the future.