this is "nightline." tonight, breaking the ice. a legendary climber moving mountains to document glaciers in danger from climate change. risks and rewards guiding scientists through icy terrain. the vanishing landscapes with an urgent forecast. plus, marquee magic. the exclusive back stage witnessing the circle of life. letting it go. and a magic carpet ride. one night, three shows

genies. ♪ never have a friend like me but first, the "nightline" five.

this spring, it's out with the old and in with the awesome. as in, in with the fastest, most reliable internet from xfinity xfi. so you can be in with brilliantly connected devices in every room. and in with finding all your favorites on live tv and streaming apps with just your voice. this spring it's out with the old, and in with simple, easy, awesome. during the xfinity spring sale, get started with internet and tv for $35.00 each a month for a 1 year when you bundle both with 20 hours of cloud dvr service included. click, call, or visit a store today. good evening, and thank you for joining us. extreme athlete wl dd a living legend in the climbing community. his office usually on the ice and now melting, now tackling

climate change. here's abc's will reeve. . >> fear and danger are constant to me. they remind me to pay attention. the places that i work in are really hazardous. if you're not afraid in that environment, something is wrong with you. >> reporter: where most see a remote and unforgiving landscape, will gadd sees a play ground. there's no mountain high enough, no water fall dangerous enough for this extreme ice climber. even the mighty niagara falls proved no match for gadd. that's him on top of the frozen cascade, the first person ever to make the climb.

gadd is a living legend in the climbing world. now he's using his influence to sound the alarm about climate change. >> that was exciting. >> reporter: taking him from the last remaining ice on africa's highest peak. >> some estimates, there won't be any ice on top of kilimanjaro in less than ten years. >> reporter: to the depths of the melting arctic. a remarkable journey that all began here in the far, freezing reaches of the canadian rockies. how long have you been coming to this glacier? >> i just figured it out. i've been coming here for 45 years that i remember. i remember being a kid in elementary school and driving out with the family, and the glacier being right here. today it's way back there. >> reporter: a warning of the effects of climate change. >> there should be a glacier here. >> reporter: why should anyone care about a melting glacier? >> glaciers are the symptom.

when glaciers are retreating this quickly, something is changing very, very quickly in our world. >> reporter: the glacier has lost more than half its volume and receded nearly a mile in the past 125 years. yearly markers let visitors know just how much has vanished over time. unassuming monuments with profound implications. >> when i come back here and i see that the glacier's receded more, it's a reminder of how quickly things are changing. it's an obvious marker. you read in the newspaper about climate change. it's abstract. but you come out here and the glacier has moved. >> reporter: after years of watching his ice melt away he felt compelled to put his climbing skills to use. >> okay, martin. >> reporter: by guiding scientists into places once thought inaccessible. >> good, martin, doing great. >> reporter: with gadd leading the way in 2016, scientists were

able to explore the inside of the glacier for the first time in history, prompting unexpected discoveries. >> that's biofilm. you look at a glacier, and i would think nothing's living in here. >> that's what we believed. it's cold, now we know we're completely wrong. >> reporter: and there's evidence right there, right? >> and totally accidently we found new life forms down there. that's a special thing. i'm athlete, but to help our collective knowledge move forward a bit is really satisfying to me. >> reporter: the united nations recognized gadd's impact in 2019 naming him a mountain hero. >> having will on our project was critically important for us, because we were going into a cave with some unknowns. >> reporter: jason gully, a

glaciologist toe universi glaciologist at the university of south florida recently enlisted gadd's help. >> we got winds around 50 miles per hour, temperatures dropping below zero. and we drop in to what happened to be one of the cool eaest cavs i've ever entered. >> i've never been in anyplace like this ever. >> me either. this is next level for sure. >> reporter: gadd took s noose scientists into a plunging cave, giving them unprecedented access. >> there's tremendous research going on in greenland. if the greenland iets sheet were to melt, it would raise sea levels five to seven meters. >> reporter: and that damage can be costly. a study released just this week warns that the melting arctic could cost the global economy nearly $70 trillion.

gadd's team had hoped to the frigid waters beloet ice sheet, but here science comes with risk. >> that was exciting. >> i was afraid. there is so much debris and so much power in there, it was not a safe place to be. and this research is important. but it's not worth dying for. right there. you guys see this crack here? >> we've got a bunch of cracks. you know, that are basically in alignment with the block that's overhanging. >> really short version, that ice is all messed up. and we are not stoked. >> what we weren't really prepared for was how unstable the cave was. there'd be these big chunks of ice previously attached to the ceiling that had fallen onto the floor. >> that's end of it right there. the ceiling comes down, the pool goes into it. we couldn't go any further. even if we were crazy enough to

come here and die, and now i think it's an excellent time to leave. >> one of the things that we're always concerned about as sign hits is the risk of some of these projects and having somebody like will who's really, really good technically but also spends a lot of time thinking about risk management makes our job that much easier as we're doing science. >> we understand how the icecap works now as a result of the work that jason and i did together. i love that. as athletes, we're not known for being super smart, but i'm helping some super smart people get in there. >> reporter: to get a better sense about what gadd needs to teach the scientists, we had him put me to the test. a private training session in an imposing setting. >> wow. yeah, look at this. >> reporter: that's where we're going. >> climb beiing up that.

>> reporter: first, gadd showed me how it's done. sc scampering up the wall like nothing. >> as long as you do it the same it's all good. basically. >> reporter: you just have decades of experience. >> you're going to do great. >> reporter: and now. >> stand up on it. you don't need to kick right away. >> reporter: it's a grueling task. but with some moral support from the man called the best ice climber of his generation. >> victory! well done. welcome to the canadian rockies, aye? >> reporter: would i be able to go on an expedition with you to go do science?

>> you've got the basic ice climbing part, there's about four more levels of this. >> reporter: but even with the basics, gadd says there should be a sense of urgency. >> i am optimistic we can stem the tide in some way, but i think we're going to have a lot of pretty wild change on our planet. and i'm going to teach my kids to expect radical change and embrace it. short term, we're in it. it's going to be difficult. long term, i think when people pull together they can do anything. >> reporter: i'm will reeve. >> you can watch "beneath the ice" on the rid bull website. coming up, three disney shows on one night on broadway. a circle of nightlife. ♪ circle of life the potential excited about of once-weekly ozempic®. in a study with ozempic®, a majority of adults lowered their blood sugar

and reached an a1c of less than seven and maintained it. oh! under seven? and you may lose weight. in the same one-year study, adults lost on average up to 12 pounds. oh! up to 12 pounds? a two-year study showed that ozempic® does not increase the risk of major cardiovascular events like heart attack, stroke, or death. oh! no increased risk? ♪ oh, oh, oh, ozempic®! ♪ ozempic® should not be the first medicine for treating diabetes, or for people with type 1 diabetes or diabetic ketoacidosis. do not share needles or pens. don't reuse needles. do not take ozempic® if you have a personal or family history of medullary thyroid cancer, multiple endocrine neoplasia syndrome type 2, or if you are allergic to ozempic®. stop taking ozempic® and get medical help right away if you get a lump or swelling in your neck, severe stomach pain, itching, rash, or trouble breathing. serious side effects may happen, including pancreatitis. tell your doctor if you have diabetic retinopathy or vision changes. taking ozempic® with a sulfonylurea or insulin

may increase the risk for low blood sugar. common side effects are nausea, vomiting, diarrhea, stomach pain, and constipation. some side effects can lead to dehydration, which may worsen kidney problems. i discovered the potential with ozempic®. ♪ oh! oh! oh! ozempic®! ♪ ask your healthcare provider today about once-weekly ozempic®. there are roadside attractions. and then there's our world-famous on-road attraction. if you've never seen yourself in a mercedes, you've never seen these offer. lease the 2019 glc 300 for just $479 a month at the mercedes-benz spring event. hurry in before april 30th.

bigger, tastier strips of juicy chicken with crunchy batter. spice them up with hot sauce or cool them down with buttermilk ranch. try my 100% all-white meat spicy chicken strips combo today. only at jack in the box.

tastier... i was literally born for this. ♪ you had me at fried chicken pacifier. try my new spicy chicken strips combo today.

with 100% all-white meat chicken. ♪ and i'll say, mr. aladdin, sir, what will your pleasure be ♪ ♪ let me take your order ♪ you ain't never had a friend like me ♪ it has been 25 years since disney launched on broadway. now the exclusive backstage look. here's j here's gio benitez. ♪ the past is in the past >> reporter: from letting it go. ♪ let it go >> reporter: to making a royal entrance. ♪ ♪ >> reporter: even turn aing a theater into the african

savannah. disney has brought some of its most majestic stories to life on a stage. now nine musicals, one play and 20 tony awards later, disney on broadway is celebrating 25 years on the great white way. to mark the occasion, "nightline" was invited on an exclusive tour to see the show the way the audience never gets to see it. tonight we're going to do something we've never done. we're going to go to all three broadway shows on the same night. we're here at the first one, "the lion king". let's check it out. how long does it take you every night? >> 50 minutes for the makeup. >> reporter: they're getting ready for the first scene here, the circle of life. ♪ >> reporter: 10 year old me never thought i would be back stage at the "lion king". we just finished at the "lion

king." now we're heading into "frozen" to see "let it go." ♪ let it go ♪ let it go >> singing "let it go" in our production is like a duet with the audience. i feel the energy. ♪ >> reporter: our final stop, "aladdin." we've got less than ten minutes to get there. let's go! this is prince ali, is that what we're going to see? >> y >> reporter: the curtain's going up. ♪ ♪ >> reporter: athey're running of stage, getting changed and running back out there.

it's unbelievable. ♪ >> reporter: every detail is overseen by thomas schumacher, the president and producer of disney theatrical productions. you're not looking at the animated film but the story that inspired that animated film. >> sure, because of course the vast majority of the animated films made by this company would not make a good stage show. you have to look at what is the element inside of it. and sometimes that's elusive. >> reporter: disney theatrical productions which is owned by disney, the parent company of abc news currently has 21 disney stage productions in nine countries worldwide. what is it that makes a good stage play, a good stage musical? >> i wish i had an easy answer, because you search. but for example on "aladdin." the animated movie is absolute cinema. and the stage version is theate.

but what they share is the source material. they share the extraordinary music behind it. >> reporter: the challenge is bringing these animated characters to life on stage. >> when i feel anxiety, i try to remind myself that everybody out there knows the words to the song because they love the song. >> reporter: and the ensemble of the tony-winning "lion king", groundbreaking for puppetry. the pressure in performing these songs that everybody knows, what's that pressure like? >> it's fortunate that we have people who are supporting us who make sure we are always ourselves within the character. because we cannot fit into a template of whatever person knows the character is. ♪ >> reporter: perhaps no disney character is as ron williams' g. you're coming out here and bringing a whole new kind of

genie. >> i never even thought that i would be the genie. of course i immediately start thinking about robin williams, but disney has allowed us to bring us, you know, they supported me to let me bring the thing that i do to the role, like all the gene kelly and fred astaire. there's also some beyonce thrown in. >> reporter: i saw that. >> there's some patti labelle . there's some whitney. >> we have one, two, three, four, five genies. >> reporter: the five men donning that blue on the anniversary, topping off their performance with the ultimate showstopper, "friend like me". ♪ >> it is a beast of a number. you really have to learn how to pace yourself. >> reporter: the genie is metim. >> to be in theater and be a large black man and for there to

be a space for us there's just. >> there are not many roles right now that can give you a full resume in one performance. >> exactly. >> reporter: and they hope their performance inspires others like them. >> i saw my first show here. saw the "lion king " at the age of 10. i know what seat i was sitting in, the ninth row. every time i do the show here, i give an a little extra love to the person in that seat. to see that little round, brown kid in the audience and knowing i was him when i was little looking for someone that looked like me is the best feeling in the world. >> reporter: disney on broadway has come a long way from where it started 25 years ago. nay sayers doubted they could succeed on stage. but with "beauty and the beast", they were saying these aren't broadway people. >> much of the artistry of it, putting it together and the business of it was not nearly as respected as is it today. >> reporter: for all the success

of the films, not all shows have been hits, like "tarzan" and "the little mermaid". >> they didn't deliver on what my expectations were. and that's hard. that's my responsibility. you laur learn from those mistakes. i have no regret about it. because i think we were trying a big idea. >> reporter: as disney looks to the future, that tale has come all the way back to broadway. >> you can't keep a secret. because you know how many people it takes to work on a show? i'm not announcing location or time. but i'm deep in it. it's happening. >> reporter: susan eagan was broadway's first belle. and to know you were the first princess. >> isn't that nutty? it feels like somebody else. a chapter so long ago. >> reporter: on this night, eagan is taking the stage to celebrate the show's first anniversary with the song that

started it all 25 years ago. ♪ rising in the east ♪ beauty and the beast >> our thanks to gio. and next, what is the newest jeopardy record? get in the way? embrace the chance of 100% clear skin with taltz... the first and only treatment of its kind offering people with moderate to severe psoriasis a chance at 100% clear skin. with taltz, up to 90% of people quickly saw a significant improvement of their psoriasis plaques. don't use if you're allergic to taltz. before starting, you should be checked for tuberculosis. taltz may increase risk of infections and lower your ability to fight them. tell your doctor if you have an infection, symptoms, or received a vaccine or plan to. inflammatory bowel disease can happen with taltz, ready for a chance at 100% clear skin? including worsening of s ask your doctor about taltz.

and i don't add up the years.. but what i do count on... is boost®. delicious boost® high protein nutritional drink has 20 grams of protein, with 26 essential vitamins and minerals. boost® high protein. look for savings on boost® in your sunday paper. but their nutritional needs remain instinctual. that's why there's purina one true instinct. high protein for strong muscles. a different breed of natural nutrition. purina one true instinct. also in grain-free for dogs and cats. stop fearing your alarm clock... with zzzquil pure zzzs. a drug-free blend of botanicals with melatonin that supports your natural sleep cycle so you can seize the morning. zzzquil pure zzzs. readyaveeno's sheer formulaiant? packed with pure soy evens tone and texture. so skin looks like this. and you feel like this. aveeno® positively radiant get skin happy™

featuring three new dishes that are planked-to-perfection. feast on new cedar-plank lobster & shrimp. or new colossal shrimp & salmon with a citrusy drizzle. tender, smoky, and together on one plank... ...but not for long- so hurry in!

finally here tonight. the major victory for one "jeopardy" champ. meet the newest millionaire "jeopardy." taking just 14 days, the all-time record is $2.5 million. but it took ken jennings 74 stays to do that. this strategy in get big. that's "nightline" for tonight. full our three contestants are all at the big ikea table. contestant #1, impressive knife skills. but contestant #2 fights back by using fresh parsley. make room for the judge! live together. lounge differently. ikea.

today, life-changing technology from abbott is helping hunt them down at their source. because the faster we can identify new viruses, the faster we can get to stopping them. the most personal technology, is technology with the power to change your life. life. to the fullest. "said alice.nd curiouser," "the rabbit-hole went straight on like a tunnel for some way." "i've seen a cat without a gri,