$ElNiño
The last time an El Niño this strong hit, it killed 50 million people. That was 3 to 4% of the entire world population. Scale that to today and you're looking at 250 million equivalent. The 1877 Super El Niño triggered simultaneous droughts across India, China, Brazil, and East Africa. Crops failed on four continents at the same time. The famine lasted three years. Researchers have called it "arguably the worst environmental disaster to ever befall humanity."
