dr. kimberly prather is a chemist at scripts institution of oceanography. we can see how dust and sea spray affect weather appearance. >> are you saying that aerosols impact weather ? >> if you're a polluted urban region, dirt and soothe are effect the rain that comes out that have cloud. >> understanding how these particles played a role . >> the choices that humans make are going to be the thing that determines how fast we can fix this problem. >> coming up on "techknow"," summing up tropical force wins. we want to hear what you think about these stories. join the conversation by following us on twitter and at www.aljazeera.com /techknow. >> every sunday night. >> i lived that character. >> go one on one with america's movers and shakers. >> we will be able to see change. >> gripping... inspiring... entertaining. no topic off limits. >> 'cause i'm like, "dad, there are hookers in this house". >> exclusive conversations you won't find anywhere else. >> these are very vivid, human stories. >> if you have an agenda with people, you sometimes don't see the tr

dr. kimberly prather is a chemist at scripts institution of oceanography. we can see how dust and sea spray affect weather appearance. >> are you saying that aerosols impact weather ? >> if you're a polluted urban region, dirt and soothe are effect the rain that comes out that have cloud. >> understanding how these particles played a role . >> the choices that humans make are going to be the thing that determines how fast we can fix this problem. >> coming up on "techknow"," summing up tropical force wins. we want to hear what you think about these stories. join the conversation by following us on twitter and at www.aljazeera.com /techknow. >> welcome back to techno. we're talking extreme weather defense. over the past year we've seen some big ones. >> the scientific community is tackling this head on, but there are a lot of economic consequences as well. when money is involved eyebrows raised. >> noaa said there were eighth weather events that cost over $1 billion and we i went to a lab that can stimulate that kind of devastation. let's take a look. >> in

dr. kimberly prather is a chemist at scripts institution of oceanography. we can see how dust and sea spray affect weather appearance. >> are you saying that aerosols impact weather ? >> if you're a polluted urban region, dirt and soothe are effect the rain that comes out that have cloud. >> understanding how these particles played a role . >> the choices that humans make are going to be the thing that determines how fast we can fix this problem. >> coming up on "techknow"," summing up tropical force wins. we want to hear what you think about these stories. join the conversation by following us on twitter and at www.aljazeera.com /techknow. >> sunday night. >> 140 world leaders will take the podium. >> get the full story. >> there is real disunity in the security council. >> about issues that impact your world. >> infectious diseases are a major threat to health. >> "the week ahead". sunday 8:30 eastern. only on al jazeera america. >> welcome back to techno. we're talking extreme weather defense. over the past year we've seen some big ones. >> the scientifi