There are a few ways of answering this question, depending on what you think it means. If there was a God, could God find a better way, than exterminating the plant kingdom, and saturating the soils with salt? Yes, God could simply snap his fingers, and all bad people would die, due to God effects. Makes for a less dramatic story.
 In the old days, the world was full of corrupt people, except for Noah and his family.
 God didn't like the corrupt people, so he made them all die. This left Noah, who's job it was to repopulate the four corners of the Earth.
 LORD God said, I shall help you repopulate the Earth, and shall make Noah multiply by one hundred thousand, and his wife and children.
 So, it was done. The world was full of Noahs.
 Noahs had a beer, and had a party with one thousand other Noahs. He had sex with his daughters. He sold some of his sons to other Noahs, to be sex slaves, and then beat some of his wives.
 After a while the other Noahs gave him the shits, so he decided to see how many he could kill in a single day.
 God came to him and asked, Why have you killed so many Noahs? They were to help fill the Earth.
 Noah said, I am the only true Noah.
Mind you, I think a skilled writer could make something of another story.