host: gross or great? composted human feces fertilizes vegetable gardens. new trees for australia's outback -- climate protection or greenwashing? and in japan, young people are swapping big city stress for quiet country life. but what then? ♪ sato: i came to this village because i fled home. i wanted to be a tv presenter.

i took all the tests but failed them all. i was thinking things over a lot. my parents begged me to get serious about finding a job. reporter: but he didn't want his parents to dictate his life. that's why four years ago, yuta moved from the big city to the small village of nanmoku. it has the highest proportion of over 65-year-olds of any japanese village. now, yuta plants flowers here. sato: what i liked most when i came here was the nature and the kind people. reporter: but the population is falling. around 2000 people live in nanmoku, for now. the number has halved in the last 20 years. every month, it drops by another 10. it's the same in many villages

across japan, which has the world's oldest population. the birth rate has been falling for decades. people are living longer, and the relatively few young people go off to work in the cities. but a trend has emerged in the other direction. since the covid-19 pandemic, more young people want to move away from the city and into the countryside. they're opting for peace and quiet, trading job prospects for space, and city life for tranquility. they're looking for an alternative lifestyle that breaks with their parents' traditions. and being able to work from home makes it easier to start afresh in the countryside. nevertheless, 150 kilometers northwest of tokyo, most of the houses in nanmoku stand empty. yuta's partner has also moved here, but right now she's at her parents' because she gave

birth to their second child just a few days ago. sato: i feel a bit bad for the kids that we moved here. it wasn't a problem when it was just my wife and i. but my daughter has no friends her own age, and i feel sad for her. reporter: she's the only three-year-old in the village. but yuta still wants to give things a go here, because he believes the place has potential. he set up a foundation that works to attract people to the village. we meet a neighbor. he's thrilled the young family has moved in. he was born here and is now retired and is renovating his parents' house. ichikawa: new couples often have kids, which is nice. there's more life here. reporter: as a newcomer, yuta said he initially felt like a bit of an outsider. but he's had a lot of support. the village hired him to look

after the natural history museum. it's located in an old schoolhouse that's no longer needed because of the lack of children. the size of the museum gives an idea of how prosperous the area -- known among other things for its silk -- once was. along with the museum and flower growing, yuta has another job -- a delivery service that brings residents lunch from the village restaurant. today, he's on his way to a family that owns the garage. the local government pays him for his work. it's a service for the village residents that also helps to support local businesses like this. funding to start a business and even the offer of free housing

are just a couple of ways that villages are competing to attract young people. competing to survive. a three-hour drive away, residents in the village of kanuma also cherish this kind of support. morizaki: in this rural region, there's just the right amount of information and opportunities. if you want to do something exciting here, you'll get help. reporter: these three women are doing just that. they're taking us to the place where they met, to restore this giant buddha statue together a few years ago. when their contract from the restoration firm ended, they decided to set up their own company. 34-year old reiko is a graphic designer, who's developed a love for old statues. morizaki: this statue was our company's first project.

we had to create a replica of the original, which was extraordinary. you don't get the chance to do that very often. reporter: they've been in their new studio for two years. a woodworking company built it for them in the corner of a warehouse, for low rent. reiko explains that they actually earn too little for the quality of their work, but it's enough for a life in the countryside. morizaki: when i hear stories from people living in the city, i often get the impression they're exhausted by life. reporter: to show they're not the only young people here, they take us to the new community center. they also want to build a new social life in their new home. the villages that do manage to attract a few young people often trigger a snowball effect, especially in places

that are well connected to big cities like tokyo. tsuji: it takes about 1.5 hours to drive, about the same by train. so you can still go into the city. it's nice being able to combine these different ways of life. reporter: the number of young japanese people reaping the benefits of rural life continues to grow. they're helping to keep at least a few of the old villages alive. host: many cities have their own share of green oases. here are our top tips for europe. announcer: whether in the countryside or in the city, nature has a positive effect on mental health and can decrease climate anxiety. with seven out of 10 young people worried about the environment, following the example of these green european cities could help. first up, oslo, norway. this capital city is surrounded by forests. bern, switzerland lies in the

alps and is blessed by nature. slovenia's capital ljubljana won the european green capital award. berlin is home to many parks and green spaces, including the famous tiergarten park. 39% of madrid is covered by trees. residents love the city's parks and gardens. belgium's capital is home to the famous brussels park. and finally, we have vienna, austria. this capital city is filled with green spaces, including the famous schönbrunn palace gardens. which one would you like to visit first? host: factories that pollute the air can buy carbon offset certificates. that money might go to farmers to plant trees, or to environmental organizations, while factories keep on pumping co2 into the atmosphere. is this climate protection or just greenwashing?

and how does it work in australia? reporter: things are going well for cattle farmer michael dempsey, not least because of the extra income he's receiving from carbon farming. that is, the capture of carbon dioxide on his vast acreage. his farm became eligible because the previous owner constantly cut down the trees. the deal is that michael gives nature free rein. the trees can grow, capturing carbon dioxide, and he gets a co2 credit. michael: that sort of hillside is typical of what they've put in the carbon credits. that's regrowth that i don't want to clear, and there's still grass growing in it, and you know, if i did clear it it's going to cause more erosion so i'm happy to let that grow. so that's typical, like that side of the mountain. and then round on the other side of the mountain there, the regrowth. reporter: he's not even required to plant new trees.

and his wagyu cattle still have more than enough room on his sprawling estate. an agent takes care of the bureaucracy for him, selling his co2 credits to airlines who are looking to become more green. the first check just came in, for the equivalent of almost 190,000 euros. michael: a lot of farmers are talking to me about it, yeah, asking me questions about how successful it is. and the money's gone in the bank, so that's the proof. so, i'm a sold customer, i'm very happy with how it's going. so yeah, people are talking about it. reporter: it sounds like a win-win situation, because companies are increasingly in need of co2 certificates. it's become a big business, worth around 280 million euros a year in australia alone. professor andrew macintosh helped to set up the rules for

emissions trade down under. but he's since become one of their biggest critics. in his opinion, 70% to 90% of projects don't deliver what they promise and offset hardly any co2. he says the authorities have approved too many projects, especially in australia's dry savannahs and scrubland. andrew: the regulators or administrators, they are often under a lot of pressure to ensure credit supply. so they're incentivized to focus more on project participation and credit supply rather than integrity. the reason for that is, fossil fuel interests use the credits in order to meet their legal obligations. so if there's no credits, the carbon price is much, much higher. so that's the pressure, keeping the carbon price low so you can keep the fossil fuel industry happy, essentially. reporter: the australian government disputes that. but macintosh tells us of a project in the middle of australia's red centre. we head to the outback -- not

exactly the landscape that most customers will have in mind when they want to offset their co2. this is the farm of jake and francesa fennell. it covers more than 381,000 hectares. they've registered around 65% of it for trading with co2 certificates. it hasn't made any money yet, but jake, whose family has farmed the land for six generations, has high hopes. jake: i think it's really important because a lot of people want to regenerate their landscape, but, for one, you have to be financially viable to do it. so to make such big changes and put a lot more fences and borders in, well, there has to be someone else to come through and help you with it. overall, i think it would just make protein production more sustainable. francesca: most farmers are really good land managers, so they should

be rewarded for what they're doing. reporter: the fennells were initially skeptical that their farm would be suitable for co2 certificates, but sought advice and now believe that they will provide extra income at some point. they practice cattle rotation, grazing their 4000 cows on various different meadows. jake: so, in our country, it's mulga. you move the cattle around, because they plough the ground up and eat the grass off to a point that it opens more country up for the juvenile mulgas to get going. and then by rotating the cattle out of that paddy, once the trees are established, they can get above two meters and then the cattle can graze on them as much as they want and it won't affect the tree, it will only keep getting bigger and bigger. reporter: andrew macintosh says a project like that should never have been registered because the area gets less than 300 millimeters of rain each year. andrew:

this is incredibly dry country where it's just not possible to grow even native forests. there are some trees out there, absolutely there are. it's useless from a climate perspective, absolutely. it's got real biodiversity value, absolutely. but in terms of helping us meet our climate targets and reducing greenhouse gas emissions, this project is not going to do it. reporter: sydney's green collar is the biggest investment firm in australia to trade in environmental certificates. manager james schulz says the system may not be perfect, but it's better than nothing, what with 30% of emissions coming from the rural sector, for example, in logging. james: there's no way we could ever create enough carbon credits to solve the fossil fuel industry. carbon credits are not going to keep fossil fuels in business, at least not in australia. what we do need to do though is drive investment into the land sector. we do know that we have to solve these large-scale land clearing issues, habitat loss

issues, biodiversity issues. and that costs money. and it costs a lot, lot more money than we have in government financing available to pay for it. reporter: farmer michael dempsey has profited from that. his yearly check is there to help him in dry spells or if meat prices fall. at least from his perspective, australia's carbon farming program is a real win. host: are we flushing away a valuable resource? in mexico, human feces are being used as fertilizer to produce tasty vegetables. reporter: tomás villanueva is so pleased with the day's harvest that he breaks into song as he delivers a sample for the kitchen. his wife liliana aranda will

use it to prepare lunch. after working outdoors, everyone is hungry. we thank the water for watering the plants, the compost for feeding them. that compost was made from human excrement, all perfectly normal for farmer tomás villanueva and his family. even at the dinner table, it's no taboo, given their salad and vegetables were grown with nutrients from human feces. on the edge of the small mexican town of tepetixtla, in the state of mexico, the ollin tlalli farm grows fruit and vegetables. everything here is fertilized exclusively with homemade human dung. tomás: we're completing the cycle. what comes from the earth is digested and excreted. the process of composting allows

us to give back to the soil what we took from it. so we complete the cycle and life continues. reporter: they eat their own vegetables, but they also sell them at markets. all plants need nutrients to grow, especially nitrogen and phosphorus. ollin tlalli is a fully organic farm and artificial fertilizers are banned. tomás villanueva says they're expensive and bad for the soil. so he and his team invest a lot of time and effort collecting excrement from dry toilets, mixing it with natural ingredients like stone powder or straw to transform it into a rich compost over a number of months. the activity of bacteria leads to high temperatures during composting. that heat kills any pathogens. tomás: this compost here is now ready.

and it smells pleasant, like fertile soil. reporter: they use it to grow various types of cabbage, beetroot, broccoli, fruit, and a whole lot more. we've come to the small town of ocotepec in the state of morelos. here, architect césar añorve has also looked at ways of recycling feces. he decided to try out something completely new. césar: this is an ecological neighborhood that i set up more than 20 years ago. i wanted to show that homes can use dry toilets and not pollute any water. reporter: in other words, toilets that divert the urine away from the feces and that are not flushed with water. these toilets are not connected to the sewage system either. dalia: urine lands in the front here, poop at the back. just add a bit of soil and

that's it. reporter: a lot of raw sewage in mexico flows directly into lakes, rivers, and the sea, something césar añorve finds outrageous. he believes dry toilets are the solution, and gives workshops teaching people how to build and use them. but getting people to actually talk about poop is the biggest challenge. césar: it's like they're afraid of it. reporter: but his sanitation system forces people to think about the subject, rather than just flushing it away. césar: as an architect, i discovered that in my profession water is seen as a means of transporting away feces and urine. i found that terrible. so my work aims to change this perception of water. what i'm doing is reviving the

knowledge and understanding of water that our ancestors had. they didn't see excrement as something dirty, but as something that needs to be returned to the earth. reporter: those ancestors used human feces and other organic waste to develop fertile islands known as chinampas, used for growing crops in wetland areas. they've been used in mexico since ancient times. on one chinampa on the edge of mexico city, lucio usobiaga wants to keep that heritage alive. lucio: the chinampas are one rare example of how we humans have helped to promote life and biodiversity. so they're a very powerful example of how we can live in harmony with nature. reporter: he runs a regenerative farming project called arca tierra. the idea is to grow organic

produce working as closely as possible with nature. the produce is then sold to restaurants in mexico city. dry toilets are a must here. there's neither electricity nor running water and the chinampas are protected areas, so waste needs to be dealt with. lucio usobiaga sees the excrement that has been collected here as a resource. lucio: we need to give back to the earth what we've received in the shape of food. otherwise you get an imbalance, leading to pests and depleted soil. to feed the plants properly you need to return all that's left over back to the soil. reporter: right now, they're only fertilizing fruit trees with human dung. they want to first make sure they can reliably filter out any pathogens, residual hormones, and medication in the compost before they start using it for vegetables too.

back to the ollin tlalli organic farm. tomás villanueva's customer know how his vegetables are grown, and they wholeheartedly approve. tomás: poop has a bad image in our society, but we know that this composting process makes it perfectly hygienic. and we always like to say that with poop you never lose a harvest. reporter: a cycle of giving and taking, eating and excreting. something that triggers revulsion elsewhere is seen here as the most natural thing in the world. ♪

dubi: hi. i'm dubi gawusas from sesfontein. i am a grade 11 learner at elias amxab combined school. sesfontein is a mountainous area. as you can see, there are a lot of mountains here. it's really a dry area with a lot of wild animals. if you just go to the side of the river, you'll find a lot of wild animals, such as elephants, the springboks, and possibly a lion. because there was a lion close by here near to our hostel. i have six siblings. two brothers and four sisters. my mom is a cleaner. she works at the regional office. and my dad is a tourist guide.

i really do like going to school. mostly our teachers normally tell us education is the key to success. it's a really important thing. without education, there's nothing which you can do. it's the only solution for you. mostly i'm afraid of snakes. i really dislike them. they are soft, they are really not my thing. it's like, the way they move, it's not good for me. i'm really afraid of snakes. there was one big, huge, huge, huge snake, which we saw here. it was a big one, and then it bit a lady that was staying here. and then she died. during my free time i normally listen to music or write a diary entry in my diary, to feel relaxed and feel in a comfortable space. and also watching movies.

my hopes are, i would like our country namibia to be a developed country like other countries. really, in namibia, we are suffering. as you might also know, we are currently in an economic crisis. it has been happening for a while and then covid hit us. and it's pretty bad. i will study education to be a teacher. and once i'm done with education, after a while i will go back again and go study law, to be a lawyer. and then again, a pilot. i really want to travel. after travelling, i will then settle down. i will rest, i will retire. and then with the money i gathered, i will start a up café or a restaurant. ♪

[captioning performed by the national captioning institute,