host: welcome to "global 3000." pollutant-free fishing -- electric boats on lake victoria. the big comeback -- bison are returning to the american prairie. and catastrophic die-off -- coral reefs on the brink of extinction. the latest report on climate change has the u.n. sounding the alarm. sec. guterres: many ecosystems are at the

point of no-return now. unchecked carbon pollution is forcing the world's most vulnerable on a frogmarch to destruction now. the facts are undeniable, this abdication of leadership is criminal. host: the intergovernmental panel on climate change's latest report offers a sharp wake-up call. around 3.6 of the almost eight billion people on earth live in regions severely threatened by climate change. temperatures continue to rise. 2021 was one of the hottest years since records began. global heating has dramatic consequences for people and wildlife. extreme weather is becoming more common. our oceans and seas are heating up, becoming more polluted and ever more acidic. can we still save these ecosystems? we head beneath the waves. reporter: coral reefs are unlike anywhere else on earth.

they're home to mind-blowing biodiversity. the world's reefs are shown with red dots here. lizzie: they cover less than 1% of the ocean floor, but they actually support over a quarter of all marine life. reporter: considerg these stgering statistics, it's easy to forget that they're actually built from tiny animals, coral polyps. corals owe a greateal of their magic and their autiful n between organisms. algae live in the polyps' tissue and provide nutrients to the coral in exchange for protection. but this delicate teamwork is under threat from climate change. co2 emissions dissolve in the seas, making waters more acidic and weakening coral skeletons. and that's not all. aslobal temperatures soar, coral reefs suffer through ever more frequent and tense ocean heat waves. extreme mperatures cause the algae to produce harmful chemicals, prompting the coral

polyps to kick them out. exthis is “coral bleaching,” where vibrant polyps turn white from heat stress, a process that can eventually prove fatal. and global warming is already driving vast bleaching eves today. sherry: my son is four, as i told you.y never sea coral reef. it really scares me to think of a world without coral reefs. reporter: sherry constantine of the nature conservancy has established a large-scale conservation project in the eastern caribbean. the goal was to protect corals and other ecosystems, while still enabling some tourism and fishing in specific eas. sherry: the fact that the community was so involved in the designation, the design of these areas, that is why it was so successful. reporter: there are also plenty of ways to enhance conservation efforts like these. take playing underwater sounds

to lure back fish, for one slightly surprising example. and there is evidence that by shielding reefs from local stresses, marine protected areas build resilience in the face of ocean acidification and rising temperatures. lizzie: so, we have to have multiple strategies in addition to marine protected areas. reporter: this is lizzie mcleod, who's global coral reefs lead at the nature conservancy. researchers like lizzie mcleoud are going one step further in the quest to help reefs resist climate change, by investigating how to actually toughen coral reefs up. lizzie: and so some of the strategies people are using are taking corals that are, we call it stress hardened, so they're better able to deal with ocean warming. and actually transplanting them, moving them from those areas to other areas, with the hopes that they'll pass along that trait to their offspring and help the corals in that new area be better able to cope with warming. reporter:

one way of doing this is to find naturally heat-resistant corals that have survived hot waters before, and to transplant them from one reef to another. and these aren't the only cutting-edge techniques. other teams are also hoping to toughen up the individual corals themselves. madeleine: in my research, we are mostly focusing on increasing the tolerance of corals to heat. reporter: this is ecological geneticist madeleine van oppen. she's investigating a range of approaches to make corals more resistant to rising temperatures. for example, selectively breeding to toughen up the polyp animals. or, alternatively, tinkering with the algae that give coral their colors. madeleine: the microalgae that live inside the coral tissues, we can take them out of the coral and most of these can be cultured in the lab.

and in the lab, we can increase the rate by which these algae evolve. reporter: madeleine van oppen used this approach to create heat resistant algae, which, when put back into polyps, created more heat resistant corals. so, if we combine all these approaches, is that it? will we be able to save these unique ecosystems from climate change? lizzie: if we implemented every tool in our toolbox today, from marine protected areas, reducing pollution, using some of these more active interventions, stress hardening or manipulating the genetics of corals, it will not be enough to save coral reefs if we do not reduce emissions. that is absolutely central. reporter: the truth is that coral reefs are incredibly sensitive to warming waters. in 2018, the intergovernmental panel on climate change warned that even if the world limits global warming to 1.5 degrees, coral reefs could decline by 90%.

if temperatures increase by two degrees, that figure is 99%, or higher. but the world could heat up by even more than this, given our emissions path. if we don't fight to stop climate change, the fight to save coral reefs is doomed. not in the distant future, but within just a few decades. coral reefs could be the first ecosystem entirely lost to the climate crisis. our environmental decisions around the world, whether that's reducing plastic use, or limiting global warming, could make all the difference for the future of the world's reefs. host: they're small and made of plastic -- sachets. these little packets might be handy, but they quickly land in the garbage bin, and they don't rot. in our web special, we chart the journey of such a sachet, from the origins of the raw materials it's made from, to its end on the rubbish heap.

we find out why the number of sachets is growing, and why they're so lucrative for businesses, and so disastrous for our planet. find out more at dw.com/plastic. lake victoria is the biggest lake in africa. around 30 million people live near it, and many of them depend on it for their livelihoods. but population growth has contributed to overfishing and pollution, threatening the health of the lake. but there are solutions. for “global ideas,” our reporter julia mielke headed to kenya where local fishers are using climate-friendly boats. julia: as dusk falls, jared otieno heads out onto lake victoria. since he started using an electric motor, he and his team no longer have to breathe in exhaust fumes. and it's not as noisy either. otieno is one of the few

fishermen here who started using an electric motor last year. it's much easier. before, he was constantly having to change gears. jared: also, you have to be careful with the propeller, the turbine. so, when it rotates, it may make get contact with this string or the gear. so, removing it is cumbersome. with this one, it's just automatic. julia: the fishermen use solar lamps to mark out the area where they plan to cast their large net. the light slowly attracts the fish to the surface. then in the early morning, they pull up the net. the nights are long on the lake. only after 12 hours do the fishermen return to nyagina beach in the town of mbita.

otieno shares the proceeds of the catch with the other fishermen, after deducting expenses. he only has the electric motor and batteries on loan, from a company called asobo. every morning he returns the used batteries. and in the evening, he receives a freshly charged set. asobo rents out the e-motors for the equivalent of around 38 euros a month. the batteries cost 7.50 euros per day. a lot of money for fishermen here. jad: there is a challenge. if we can get less than what we are expecting, then it's a stress to pay what we do with asobo. so, we have to go to look for other sources, so that we can top up. julia: the dutch start-up asobo had to do a lot of math to develop this business model. they source the batteries and motors from germany. here in kenya, they have technicians who take care of the repairs and maintenance.

they also offer a 24-hour service if there are problems on the water. david: the fishermen have to call the rescue number that we can resolve on call. but sometimes when the technical issues are not in a position to be solved during that time, we have to send our rescue boat to go pull them back, or maybe change something, a component of the engine for that matter. julia: the batteries are equipped with gps trackers so that the boats can be precisely located in case of emergency. asobo first started testing its system in 2017. but everything was delayed by the pandemic. in the meantime, more than 15 fishermen have signed a contract with the company. every new customereceives a free training session. in just a few days they learn the most important things. first theory, then practice on

the water, to get used to the e-motor. coach joshua miruka has been involved since the start, and understands what the fishermen need. joshua: the company will need to do some modification, only the distances that electric mobility cover. like our fishermen, most of them try to go far distance. julia: asobo is working to improve the situation. it's made contact with companies in kenya and uganda that refurbish used batteries. these could be rented out to the fishermen at a cheaper rate. gabriel: these second life batteries will make them modular, so that also we merge, we mimic the current operations of our customers. if a customer wants to go far, we give them more batteries. then we charge this recharge fee per battery. like, you want to go far, you get four batteries.

you want to go a shorter distance, you give you one or two batteries and you pay for what you have used. julia: asobo is the first company in kenya to invest in e-mobility on water, and one of the few in general on the country's e-market. electric mobility is still in its infancy here. there are some electric cars and buses, and even some e-bikes. warren ondanje rides one of them. he is a member of aemda, an association that provides a platform for the nearly 20 companies investing in e mobility in kenya. the aim is to organize a lobby, urging politicians to promote electric vehicles. warren: people are excited about e-mobility and the opportunities that it brings. it has tremendous environmental benefits. but unless we have the right incentives to allow for the final price and value to the customer to be affordable, then e-mobility might just as well

be another illusion that we will struggle to get towards. julia: around 25,000 boats are out on lake victoria every day. many of them belelong to kenyn fishermen who use combustion engines, which pollute the lake and harm the fish population. often the fishermen only get small silver cyprinids from the lake. and their catch quotas have also declined in recent years. jared otieno's wife and mother take care of the catch every morning, first drying it and then selling it as quickly as possible. the fish are the main source of income for the family of 12. they also use the money to pay the school fees for their four children. and they've even managed to build a second boat. jared otieno wants to equip this one with an electric motor too. he has a plan for his family. jared: my father was a fisherman, now it's me fishing, then what of my children?

so out of this one, i'm praying, god willing, that my children won't be fishing also, that they divert to something else. that's why now i'm supporting their education, providing good education. from there, if they are employed, they can change our lives. julia: jared otieno has already persuaded some other fishermen to switch to electric motors. but he and asobo are still among the pioneers of e-mobility in kenya. it will take many more like them to see a benefit to lake victoria and its fish. host: for thousands of years, the indigenous peoples of north america inhabited a vast region, from coast to coast. today, native americans make up just 2% of the u.s. population. a small number live on reservations, most of them in

poverty. now, some native groups are working together to revive some of their old traditions. and that means bringing back the bison. reporter: while rounding up these bison, robbie magnan needs to move fast. he's responsible for more than 50 bulls, cows, yearlings, and calves. robbie: the trick is, don't give these animals time to think. you give them time to think, they'll go back on you. reporter: before their journey to their new home, these animals have to pass one last health test. robbie: i work these guys every day, i know how aggressive you've got to be with them. reporter: here on the fort peck reservation in montana, ranchers are preparing the bison for distribution to indigenous tribes.

for years, magnan has been working hard to ensure they can roam the prairie again. they're vitally important to many native americans. robbie: you'll see them fighting and everything in here. some of them will get nervous. they get stressed out very fast, so you want to work them as quickly as possible so they won't have a heart attack on you. you try to get them in, test them, get them out, and let them go. reporter: the reservation has invested a lot of money in this facility to comply with the regulations. only after up to three years of quarantine and many blood tests are the bison permitted to be transported to other states. though, the still-wild animals

are reluctant to let that happen. robbie: they know what the problem is, and they won't go in there. they've done it too many times. if you had a bad experience every time you went through one door, you'd be the same way. reporter: they're testing the bisons' blood for brucellosis bacteria, a disease originally brought over by cattle from europe, which infected native bison. today, conventional cattle don't have the bacteria. but farmers fear their cows might come into contact with bison and contract it. so, there are strict rules and lots of testing. this veterinarian has a routine. >> there's a vein that runs down their tail. reporter: did anything happen to you during all of this at one point? >> not yet. not yet. reporter: each animal is meticulously documented. biologist megan davenport of

the intertribal buffalo council says there's no evidence the bison pose a threat to cows. megan: they've gone through 15 or 16 tests at this point in their life. there's never been a positive brucellosis test after the first phase of quarantine, which is literally just the first few months of this program. and they're on year three or so now. reporter: robbie magnan knows what it's like to wait for the lab results. the director of fort peck's fish and wildlife department shows us the reserve's pride and joy -- two herds of bison. the commercial herd brings in money, through hunting licenses. the other is a cultural herd only tribal members are permitted to hunt. each herd has 10 square kilometers of land, bordered by a fence that can withstand the bisons' brute force. though magnan calls these creatures buffalo, claiming only politicians or scientists say bison.

robbie: when the creator put us on here, we were dumb. we didn't know how to survive as humans. so, he had the buffalo come up to take care of us. and they helped us survive. reporter: many native americans see bison as four-legged family members, who are vital to their identity. but from the cattle industry's point of view, they're bad for business. robbie: they really fear that buffalo will take the grazing, which is not really true. because buffalo, what they call all year out for food, they do with one day with cattle. so we're not really in a competition with them. and this land is big enough for both of us to live, but the people don't see it. reporter: it's the big day, and it's minus 25 degrees celsius. these bison come from yellowstone national park. when huge herds were slaughtered in the 19th century, a few hundred animals

found refuge there. that's why genetically pure bison still exist today. robbie: they're dancing around and playing. buffalo are really acceptable for cold temperatures and hot temperatures. they are able to adjust a lot better than livestock. reporter: the test results have come back negative -- no bison have brucellosis bacteria. the first truck is going to washington state, the second to oklahoma. there's a whole family in each one, with bulls, cows, and calves. it's stressful for all concerned. two native american tribes hope to establish their own herds with these bison. the cattle truck is the final hurdle. megan: if buffalo were really tolerated as wildlife, just like deer and elk are and every other of these other large

north american animals, we wouldn't have to do this. but they have to be moved on trucks this way because there's no tolerance for them to be walking there on their own two feet, four feet. reporter: robbie magnan dreams that one day bison will roam free across the prairie again. he knows it's just a dream. but he's taking big risks to make it happen. in the end, they're all safe and sound, man and animal. robbie: it took a bit, but we're done. now we've got the long journey to oklahoma. they should be good. reporter: a traditional blessing for a good 20 hours of non-stop driving. every few months they transport more bison, one more step in its slow return.

>> i am -- >> -- a global teen. host: this week, our “global teen” comes from ivory coast. aiché: my name's aiché yatabaré. i'm 15. i come from mali, but live in ivory coast. i have a little brother and sister. i like to play with my little brother and tease him. we're close. i tell him everything

i like school, especially my new one. i feel good there because the teachers listen to me. on thursdays i have online classes which helps me improve my computer skills. i didn't have that before. in my free time i like to watch youtube videos, funny ones. or dance videos to dance and exercise to.

what makes me sad in abidjan is seeing all the street kids. some have no family. others do, but live on the streets, since they have no home or money. what's gotten better is that there's more freedom to express yourself. my grandmother wasn't allowed to express herself or wear what she wanted to. but i can dress how i want and say what i think. host: that's all from us at “global 3000” this week. thanks for joining us. drop us a line at global3000@dw.com, and check us

out on facebook, too -- dw global ideas. see you next time. take care. ♪ [captioning performed by the national captioning institute, which is responsible for its caption content and accuracy. visit ncicap.org]

berlin. mission aborted, a red cross convoy on its way to evaluate -- on its way to evacuate citizens from mariupol on its way back, dashing the hopes of those trapped inside the city. also tonight, a stark warning from the eu to china, don't help russia in its war against ukraine. china says it will not be