By Issam AHMED The symbolic “Doomsday Clock” was held at 90 seconds to midnight Tuesday, reflecting existential threats to humanity posed by potential nuclear escalation from the war in Ukraine and the multiplying impacts of the climate crisis following Earth’s hottest recorded year. Set by top scientists and security experts, the timing of the clock remains the same as last year and the closest it has ever been to midnight in its more than 75-year-history. […]