. >> the sugar pine seems to be suffering a lot of more at allity that we've seen. another pine as well. the cedar has been going back to a rate that people in the park have never seen before. >> reporter: it was by far the scareyest thing i've done. i've never felt so insignificant. this may be the last time that scientists climb these trees. part of this project is to test the accuracy of the airborne observeatry. >> typically in the past we've missed most of the forest and tried to make an inference from the forest from a few samples. with the advent of image ability, this has enabled us to collect data over enormous scales that wouldn't have been possible in the past >> reporter: the trees that have survived draughts for thousands of years, they are surviving. the comebacks and drought and unprecedented. >> we're in the fourth year of this severe draught. they still seem to be holding up well. if we had another year as severe as this one, i would say all bets are off >> reporter: this is one of many waterways amphetamined by snow. in that snow can't provide enou

meeting men that were nostalgic about this period that look at the mountainman as almost a spirit allity. you do all this research. but once you are get there and are put in these conditions, it's just about trust. and it's about trusting the director you are working with, and saying, you know, how are we going to persevere, what are we going to do day to day. and you just kind of rely on instinct as an actor, and all that stuff, all that preparation, all the things you have thought about sort of dissolve away. that is what this experience, i think, was for the entire cast, was a trust within one another that we're going to do something, you know, completely different sin matically. >> rose: we conclude this evening with a look at china, its economy and its financial market and its impact on the global economy. we talk to gillian tet of "the financial times" and henry mcvey of kkr. >> if you think about the chinese currency, it typically had an annualized volatility of 2% which is nothing. and right now it's four times that. we have never as investors dealt with that type of volatility i