Popow/Getty Images George Soros warned Russia's invasion of Ukraine could lead to World War III and civilization's demise. Global problems like climate change have been forced to take a backseat due to Russia's war on Ukraine, he told the World Economic Forum. He also said China's slowing economy could trigger a global depression. Hedge fund billionaire George Soros warned Tuesday that Russia's invasion of Ukraine could lead to the beginning of World War III and civilization's demise.During a dinner at the World Economic Forum, he said even once the fighting in Ukraine stops, the situation won't revert back to its prewar status.