A new study by Science Advances has shown the chance of dangerous flooding occurring in California in the next four decades has nearly doubled. Central Valley of California may be most vulnerable to a megaflood. Daniel Swain, one of the researchers in the study, said, "Ultimately, one of our goals is not just to understand these events scientifically, but it's also to help California prepare for them. It's a question of when rather than if (the megaflood) occurs." A megaflood in California may cost nearly a trillion dollars in damages.