actually have on-line that institute this bibliography and you can do searchs by author, subject, reen on, whatever. there's the url. i stuck in the word reservoir and it turns out there's 60 some odd articles on this. so this is not new scientific subject. i'll talk about four things. what should be done. there have been proposals for decades of what water managers should do both generally and specifically. i'm going to talk about what has been done and argue that actually, very little has been done. there has been a handful where things have been taken to improve our situation, but not many. i'm going to talk a little about what has not been done. there again there are far more examples we've done major things in water area but ignored climate change. and what shouldn't be done. there are things we should not do given our understanding of climate change and water resources. i can argue recently climate change is argued as a reason to justify something, either justifying not doing something or taking an action that we probably ought not to do and i'll give you some examples of that. s

that's the movie starring natalie portman, who won her first oscar, playing a prima ball reen narks drivennds of her role. she was given a lot of praise for doing much of the dancing herself. but we met the double that says she did most of the dancing. and elizabeth vargas is here. >> reporter: the moviemakers do not dispute that a dance double was used. the fight is over how much she was used. it's become an issue because it was so focused on, natalie portman's physical transformation to a ballerina after only a year and half of training. it's led to an unprecedented squabble between the moviemakers and the star ballerina. in "black swan," natalie portman wowed movie audiences with her portrayal of a prima ballerina going mad. but this woman says she did many of the dance scenes. she is professional ballerina, sarah lane. >> full-body shots with actual dancing is me, that's why they hired me. >> reporter: it's your body? your feet? >> mm-hmm. >> reporter: in this scene re-created for our cameras, natalie's face was superimposed on sarah's body. were you told you would get credit for this?