Several clear links have been established by science to the increase in natural disasters such as superstorms and flooding to global warming. Even the staunchest climate change deniers have to admit that the temperature of the Earth is rising rapidly. The floods in Louisiana are a direct result of rising sea levels.
Yes, these types of disasters are unprecedented. The floods in Louisiana are large in scope, and they happened because there was more moisture than normal in the clouds. This is a direct result of climate change, which is happening because of over-industrialization. We have to stop burning so much coal, oil and gas if we want these storms to decrease in intensity.
As the world keeps aging the more serious natural disasters are becoming, causing massive amounts of damage and more death than what has ever been seen before. Furthermore the disasters that are currently occurring are nothing compared to the ice ages, volcanic eruptions, and worldwide floods that have been experienced in past centuries.
Unfortunately the global warming problem we have is manifesting in many catastrophic storms. We can't forget basic science featuring the water cycle. We are having rain deluges which cause once in a lifetime floodings several times a year. Where do you think that water is going? It is going to continue in the water cycle and come back in different forms, hence the heavy snowstorms causing roof collapse and highway backups. It is very dangerous.