danielle notingham, cbs news, joshua tree national park. >>> coming up after your local news on "cbsrning," more on the results of a v.a. hospital's audit. and we'll speak with senator marco rubio of florida. plus, an astronaut gaining a huge following through the pictures he's tweeting. and the lloyd blank fien from goldman sachs joins us. i'm anne-marie green. have a great day.

danielle notingham reports. >> reporter: looking like sculptures in the sand, joshua trees are iconsdesert. more than a million of them stand under the blazing california sun in joshua tree national park. these trees have survived here because their roots are capable of finding water deep in the desert ground. there are early indications that rising temperatures and a severe drought have dried out their water source. josh is a park ranger here. >> this is one that's probably on its way out. >> reporter: what would the national park be without the joshua trees? >> a different feeling? >> reporter: scientists now estimate 90% of the trees in this park could dry out and die by the end of the century. >> warmer is bad. it increases evaporation and is stressful on the plant itself. >> reporter: is there a way to reverse what's happening? >> stop putting carbon in the atmosphere, that would reduce it. that will take awhile. >> reporter: they have been looking for signs of life and new growth, any clue the joshua tree has a fighting chance in the warmer world. donna thomas and her grandson