and they cause tremendous damage and actually mortality i mean two hundred thousand people have been killed in the last thirty years from coastal floods alone. there s been a lot of major coastal flood disasters over the last few years and in one thousand nine hundred one in bangladesh about one hundred thirty eight thousand people are estimated to have died in burma or in thousand eight hundred like them the grizz about one hundred thirty eight thousand people again were estimated to be killed and more recently in the philippines typhoon hyaena six thousand people were killed and those are just a few examples even in the developed world people have died in hurricane katrina about two thousand people were killed in about eight hundred of those were in new orleans and inside clone sandy about two hundred people were killed more and more people are moving to cities globally now one half the people live in cities that happened fairly recently moving from human beings being