captioning sponsored by wnet >> sreenivasan: on this edition for sunday march 17: solidarity and tributes for the victims of the new zealand massacre. a special look at what the earth beneath the oceans teaches us about climate change. and in our signature segment: generating power, from the tides and waves. next on pbs newshour weekend. >> pbs newshour weekend is made ssible by: bernard and irene schwartz.an suedgar wachenheim iii. seton melvin. the cheryl and philip milstein family. dr. p. roy vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america--

designing customized individual and group retirement products. that's why we're your retirement company. additional supportas been provided by: and by the corporation for public broadcastin and by contributions to your pbs yotation from viewers like you. gohan >> sreenivasan evening and thanks for joining us this sunday, march 17th. i'm hari sreenivasan. we're bringing you tonight's broadcast from the lamont- doherty earth observatory overloing the hudson river north of new york city. the observatory is part of columbia university's earth institute, where researchers and students work on complicated environmental issues facing the planet. we'll hear more about the research being done here and how it is helping advance our nding of climate change. but first, here are today's headlines. new zealanime minister

jacinda ardern consoled community members at a mosque and paid respects to the victims of friday's terrorist attack on two mosques in christchurch. the prime minister said authorities will begin releasing the bodies of victims to their families this evening. ne yesterday that the death toll is now 50 with the discovery of another bodmoin one of the ues. as of this morning, dozens of wounded are still in the hospital. facebook, where the gunman's live-streamed video st the attack fppeared, responded to criticism last night, tweeting that in t first 24 hours it "removed 1.5 million videos of the attack globally, of which over 1.2 million were blocked at upload. they provided no details on how widely the 300,000 copies of the video were seen or shared before removal. thousands accompanied empty caskets through the streets of ethiopia's capital oaddis abab victims of last sunday's ethiopian airlines crash.

there have been no bodies identified, so families were given a kilo of charred earth t om the crash site to bury. loved ones wep coffins during religious services. also today, ethiopia's transport y nister told reporters preliminardata from the plane's flight data recorder shows "a clear similarity" with an earlier crash in indonesia. detailed results are expected to be released within a month. in london today, parade goers waring green, donning shamrocks, aing irish flags lined the streets for the city's annual st. patrick's day parade the procession of marching bands and dancers was followed by a concert in london's trafalgar square. this year's parade comess midst questi relations between the united kingdom and ireland over brexit negotiations. the u.k. is trying to exit the european union withoutwo disrupting theecades old peace accord that created an open border between the republic of ireland and northern ireland.

new york democratic senator kirsllibrand officially entered the race for president early this morning. vi a campaign-produced two and a half minuto, gillibrand said the country needs a leader who "makes big, bold, brave choices," and she posed the question, "will brave win?" >> brave doesn't pit people against each other. brave doesn't put money over lives. brave doesn't spread hate. cloud truth. build a wall. that's what fear does. >> sreenivasan: gillibrand joins more than a dozen other democrats now in the race. she says she'll hold an official campaign launch rally next sarday in front of the trump international hotel in new york city. and was it a slip of the tongue or is former vice president toe biden abounter the race, too? >> i have the most progressive record of anybody running r thu-- anybody who would ru

( cheers and applause ) >> sreenivasan: as the applause continued at the delaware democratic party dinner last night biden added, "i didn't mean it". th76-year-old possible presidential candida has said he is considering running and will decide in "thnear term". evacuations and rescues are underway across the upper midwest as waters continueo rise after heavy rains and snowmelt. bridges and roads have washed in eastern nebraska and western iowa and the missouri river is at record levels in south dakota, iowa and minnesota. at least two people have died and others are still misng. downstream from this week's flooding, officials in missouri are now preparing for flooding there in the coming week. for updates on the victims of the mass shooting in new zealand, visit our website a pbs.org/newshour. >> sreenivasan: this is the core ret-sitory at columbia's lam

doherty earth observatory. each of these saawers holds les taken from the beneath the ocean floor. it's a collection that has tak more than half a century to build, and a treasure trnte of scic data on everything from which plants and animals thrived mill how the climate is changing today. earlier i spoke with maureen raymo, a marine geologist studying climate change and the director of the core repository. >> they're records of time. you know they're goik in time. they're like tape recorders sediment sedimentae recorders of earth's history. you can see they are from different places, they have different colors. >> sreenivasan: maureen raymo is showing me a few of the more an 18,000 core samples that have been collected from the sediment beneath the ocean. each core provides a physical record of the earth, typically representing hundreds of thousands of years. >> what these cores have been most useful for is studying the history of earth's climate. and if you think about the ocean that's like a giant you know it's like a giant bucket and

everything that either blows in orrs carried in by icebergs grows on the surface of the ocean the plankton the animals he plants all of it ends up falling to the bottom of the ocean, and it just accumulates layer by layer by layer. so you have a record of time and you can see hothe earth's imate has changed through time how the plants have changed how the temperatures have changed. >> sreenivan: raymo says the cores, like this one from the mediterranean sea, provide a record of the natural cycl of the earth's climate. so right now i'm touching something that's 50 or 60,000 years old? >>yes. >> sreenivasan: the cores also help scientists see how far off our climate is today from those cycles. >> one of the great scientific advances that came out of the ofmont core repository was the proohe theory of the ice ages and this undersg that ee ice ages come and go caused by variations in tth's orbit around the sun. >> sreenivasan: so we should be heading towards another ice agw >> so right e earth's

orbit should be making tnd earth coolerhe northern hemisphere and it's making and t's warmer observing and that's obviously because we're putting so much greenhouse gases into the atmosphere very quickly. >> sreenivasan: the cores are collected on research vessels equipped with a system that lowers a specially-designed collection pipe to the sea oor. >> imagine like you had a multi layer cake and a big straw and you just stuck your clear straw outo your cake and pulled it and that's essentially what we do in the ocean excean we have a gisteel tube with a the one ton weight of the top and it just be it gets near the bottom we release it and it just drives the core. >> sreenivasan: the tube is driven about 30 feet into the sediment and then raised back up to the ship. when you get down below the surface the geology is so different from ocean to ocean or even in the me ocean. i mean when you look at different samples different colorsrent textures. >> right, yeah. so you know there's areas of

high productivity where there's lots of plavin animal remains. there is areas at high latite es wh see lots of glacial deposits are places where there's lots of organic matter yeah. you know the patterns of sedimentation in the ocean can tell you a lot about the processes that are going on today and in the past. >> sreenivasan: cores have been collected in oceans and seas all over the world. each dot on this map represents a sample that the lamont-doherty re repository now stores when y look where these cores are from all over the planet i mean 40 50 years ago the foresight to try to do this they weren't thinking about this library now. they were doing it for what they wanted to at the time right? >> yeah, well it's really true. i mean this is tgest core repository in the world. and part of that is due to the foresight of the first director mauricewing of lemont. and even though they didn't really know what they would do with the cores h every day every ship has to stop and take a core.

and so it is pure exploration and this huge collection accumulated and that's wit's so useful now because it's very very hard to raise the funding to go out and do a scientific expedition. so if you can doour work with material that already exists that's a big win for science. >> sreenivasan: the core repository sends more than 3,0 samples a year to scientists all over the world. raymo thinks of it as a "living museum." >> it's an it's an active source of material for researchers. the entire collection even though it looks like rusty old traces everything that's in he the new material the old material. these cores were collected probably in the '50s right here. it's all digitized. it's all archived on computers. any scientists in the world can search our collection they can look for matial from a region they're studying that they want to know more about. reasons's one of t the national science foundation funds us, we're a community

facility. >>ngreenivasan: raymo is lea this week on an research expedition, which will be collecting new core samples near antarctica. she'll be on a ship for the next two months. >> it's going to a place that has never really been studied before in fact we don't even e know what e of the sediment at the bottom at the bottom will be. syoknow the ocean is vast. you know they say we know more about the surface of the moon than we know about the bottom of the ocean and there are still many, many places to explore and many uncertainties about what happened in the past especially around antarctica. >> sreenivasan: even as she brings back more samples, raymo says there are still parts of the existing collection that haven't been fully explored. >> i would say about half of them have been studied in depth by scientists. but you kno there's still a lot of undiscovered gold in this in this building.

>> sreen: ivas've been following how different countries have been investing in and developing new ways to deliver sustainable power sources. it's aba ggreen revolution with some promising early results. in december, we brought you the story of how innovative energy efforts in scothand were using forces of tidal currents to create power. that company set a world record this year for taking the pow it generates beneath the sea and exporting it to a national grid. in a giant industrial haeaar on thstern coast of scotland, technicians are servicing two turbines, each with three 30 foot blades. they're not wind turbines. these are actually designed to be 100 feet underwater, capturing energy not from thewi , but from tidal currents. >> once they get this 150 ton turbine into the water, this entire thing will swivel with the tide, four times a day, generating about enough power for 1,000 homes.

for the past year, these turbines, and two others, have been in the pentlan strait off the northern coast of mainland scotland. it's called the meygen project. >> the blades, for example, we made from carbon fiber. >> sreenivasan: eddie scott is the health and safety nager with simec atlantis energy, and part of the team that oversees these devices underwater. to get them in place, the turbines are guided onto steel bases on the seafloor. you can drop this in to its base and get it plugged in how long? >> we cadon hat within about 30 to 40 minutes. ivasan: as the tide eb and flows, the turbines spin between seven and 15 times a minute, generating power, similar to a wind turbine. cables carry the energy back to the shore, first uerwater, then underground, where it's then fed into the national grid. the tides are so predictable that atlantis says it can tell how much energy these turbines wilgenerate every 15 minutes for the next 25 years. so u n't have to worry about

whether there's clouds on a sunny day for solar. you don't have to worryerbout whether s a stiff breeze or not. >> that's the real advantage of tidal energy, it's very, very predictable. >> sreenivasan: scotland is estimated to have a quarter of all the tidal energy resources in europe. and scottish companies have helped leadlhe way in deoping technology to harness those currents. meygen, herotin northern and, is the world's largest plannaled troject and over the next four years, simec atlantis is planning on installing more than 250 additional turbines. >> wn it's fully done you're talking more than a quarter of a million homes can benefit from the por that's generated from from this array of turbines. >> sreenivasan: tim cornelius is the c.e.o. of simec atlantis energy. the company says the turbines at the meygen site are expected to last 25 years, and only need to come ouof the water for intenance every six years. >> it's in a very, very stable environment and more importantly from a permitting and consenting perspective, you don't see them and you don't hear them and that's very, very important for local communities. >> sreenivasan: but it's

expsive being first. the cost of producing tidal energy is more than two and a half times the tre established echnology of offshore wind. the meygen project has cost about $64 million so r, and has been largely subsidized with public money. almost half of the total cost has come fromhe scottish vernment. >>e we ry, very grateful for the support that we have ree ceived over st 10 years from the u.k. government and in spceecific refero scottish government support because it's been outstanding. but of course the aspiration is to eventually wean itself off subsidy. >> eesrvasan: as the project continues to expand, cornelius says costs are coming down. a year after the turbines were installed, the price simec atlantis charges the utility company for its tidal power has decreased by 50%. >> the scottish government has provided consistent long term support for thes>>technologies. reenivasan: on stage, paul he is the scottish minister for

energy, connectivity, and the islands. we sat down with him at a conference on ocean energy in edinburgh. can this industry survive without government subsidy? >> we believe key technologies are already close to being in a caposition where thesurvive without subsidy. other technologies which are tenewer, emerginnologies do need, we believe continued support to get them to commercial scale, utility scale ndojects that will then get the economies of scalehe manufacturing process and drive down the price and prove their etitiveness. >> sreenivasan: wheelhouse says these government investments will helscotland reach its goal of being 100% powered by renewables by 2020. and then there's the transfer of technology that's happening. >> the great secret abe tidal power industry is while it looks like an incredible leap forward in all we've been doing is just stealing the great ideas of the oil and gas industry over the last decade. >> sreenivasan: the facility where the tidal turbines arls maintained,supports oil and gas platforms. >> big cranes, heavy lifting

equipment, moving large portions and large chunks of steel around. some of the subsea technology is very, very similar, so there's a tremendous amount of existing technology that we're usingnd capitalizing on. >> sreenivasan: for wheelhouse, rey lying on the technold knowledge gathered from decades of oil and gas exploration means continued jobs in this new energy sector. >> we don't want to leave communities, entire communities behind as has happened in the past with al mining, you know, just abandon them and leave them to their own devices. >> sreenivasan: so you're saying th aat y creating opportunities for whether its coal miners or at oil and gas enrkers to transition to this newable economy? >> yes. >> sreenivasan: and with the growing threat of climate change wheelhouse says the time toin st in new forms of renewable energy is now. we have long argued tha there is an economic advantage in moving early not leall because we ave to do this i believe firmly that climate change is happening and we cannot avoid tackling this issue globally. >> sreenivasan: f the scottish

and u.k. governments this means investing in more than just tidal energy. vid ingram is a engineering professor at the university of edinburgh, and the director of the flowave ocean energy research facility. this 634,000 gallon tank was funded in part by the u.k. government anopened in 2014. 's a place where you can rent a stormy sea. the size of the wave o force of the tide and test whatever you like. >> s if i want to have a 200 year storm, i can have 200 year stormonditions every 15 minutes. if i go t the ocean and i want a 200 year storm i might have to for that 200 year storm to come along. >> sreenivasan: on the day we visited, this small scale version of a wave power device was being put through the equiva olemassive swells by a swedish company. >> it's much cheaper for you to bring a model here from australia and test it or from sweden and test it than it is to replicate this facilit >> sreenivasan: but while the costs of these new technologies

may be high, scotland is not the only country investing. representatives from all over europe were at the marine energy conference in edburgh. and the united states was represented as well. tim ramsey is the pr manager for the u.s. department of energy's marine and hydrokinetic program. >> we're learning as m we can from from our counterparts over here in the u.k. >> sreenivasan: ramsey's office distributes about $70 million a year in grants for marine energy, with u.s. department of energy support, tidal devices have been tested in maine and new york. the department of energy is also helping build a $50 million wave ng site on the coast of oregon. it will be able to testcatility- devices. ramsey thinks american companies still have a chance to catch up to the europeans. >> we're not as far along as them but they're not that far out in front of us. wile can catch and then we can still be the world leaders in this space when you look across the country and the resources that we do have it spans it all. we have a great tidal resource, a great wave resource. we have the supply chain i thig we'd be misst on a big

opportunity if we don't take advantage of that. >> sreenivasan: but despite the investment there are still questions as to whether or not developing technologies, liketi dal energy, can compete with existing fossil fuels and more established renewable energy technologies like wind and solar. >> tidal power is where wind and solar was 15 years ago. the world's best resources closest to distribution points are yet to be developed. re>>ivasan: cornelius hopes that projects like meygen will l prove that commercale tidal energy is feasible. as the sun sets and the moonth pulle tides to rush by at 11 miles p hour, spinning underwater turbines are helping keep the lights on. >> sreenivasan: here at the lamont-doherty co repository, ediment collected over decades tells the story of underwater life millions of yearago. it reveals a cycle of life and

death on the seabed that ctinues even today. one example-- a flourishing coral reef in the red sea, uedntouchy humans until recently. >> sreenivasan: undersea corals are threatened as warm, but in eilat, israel, along one of the country's favorite beaches, there's a project underway to rescue corals that found a home in an oil company's protecded territory. r the watch of some friendly dolphins, divers are carefully retrieving richly-colored corals before starting an underwater clean up project in the red sea. for 50 years, the eliat ashkelon pipeline company controlled and kept private part of the beach- front and underwater areas here. when the oil company scaled back operations 18 months ago, it left behinbarrels and debris and an old pipeline, all of which had made a home for spectacular and diverse coral eefs. >> ( translated ): at the bottom of the sea here there is a lot

of old waste that accumulated over the years and we need to get it out. the problem is that many corals and various natural riches accumulated on top of this waste, on top these objects, and weweeed to remove them befor take out the waste. it's a strenuous, not simple task. there are hundreds of colonies of coral that we need to relocate, one by one, golicately. >> sreenivasan: th is to derwater clean up to make thisn stretch of the now-public red sea beach and its wars safe for visitors. >> ( translated ): the most bemplicated part of opening this h is to preserve the wealth of species we have here and the uniqueness of this spot on one hand, while still allowing the public to enjoy the natural treasures in eilat bay. >> sreenivasan: that's all for this edition of pbs newshour

weeken from the lamont-doherty earth observatory, i'm hari sreenivasan. have a good night. captioning sponsored by wnet captioned by media access group at wgbh access.wgbh.org >> pbhour weekend is made possible by: dbernard ene schwartz. sue and edgar wachenheim iii. seton melvin. tcheryl and philip milstein family. dr. p. roy vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we're your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you.

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hrough programs like thi made available for everyone, through contributions to your pbs sketion, from viewers li you. thank you. to deepak chopra:on, fwhat is the purpose for which we are here? ouwhy do we want to know rselves? why do we want to know what happens after death? narrator: dr. deepak chopra world-renowned pioneer in integrative medicine and author of over 80 books, created the sevensp itual laws of success to help everyone overcome barriers to reaching their peak potential. deepak: the seven spiritual laws of success, that can change how we experience the world and allow us with very little effort to lfill our goals