Fueled by unusually warm waters, Hurricane Melissa this week turned into one of the strongest Atlantic storms ever recorded. Now a new rapid attribution study suggests human-induced climate change made the deadly tropical cyclone four times more likely. Hurricane Melissa collided with Jamaica on Tuesday, wreaking havoc across the island before tearing through nearby Haiti and Cuba. The model essentially runs simulations on the likelihood of a given storm’s wind speed—often the most damaging factor—in a pre-industrial climate versus the current climate. Applying IRIS to Hurricane Melissa is how the researchers determined that human-induced warming supercharged the cyclone’s wind speed by 7 percent.