disasters -- they've always been the three main reasons for human migration. but technological progress and new forms of transportation have made displacement a far bigger, global issue. in the mid-19th century, in order to escape starvation in their home countries, millions of irish and germans boarded steamships to the united states. in the 20th century, the second

world war forced 60 million people from their homes in europe alone. and since 2005, millions of people have fled conflict in syria. sometimes, like in africa today, all the causes of flight come together at the same time. take mali, for example. sincnce 2012, olence has overshshadowed the west africn country. islamiststs regulay atattack malian government forces and u.n. peace-keeping troops. over the past few years, 250,000 malians have f fled to neieighbg untries. now sosome of them are r returg homeme. reporter: the calm in timbuktu is deceptive, and it's mainly down to the massive presence of u.n. peacekeepers. rebels and jihadists are still operating in northern mali at the edge of the sahara desert. terror and violence have left

their mark on the city. there are too few hospitals, and many children are no longer attending school. mariam and fatouma touré are ambassadors for unicef, the united nations children's fund. they are 15 years old and are still in school. in timbuktu's old town they regularly visit families to persuade them to send their kids back to school. mariam: we go from door to door to make parents aware of how important education is. we've already persuaded a few to send their chihildren to schoo. but there are parents who say that education is not important for children. and then some of them say that it's more important to go to koranic school. reporter: not only parents' objections like these are keeping children out of school. fear is also a factor.

more than 800 schools that shut down after the political crisis in 2012 remain closed, more than 80 in and around timbuktu alone. the sidi mahmoud school is open and hopelessly overcrowded. mariam mint mohamed ali is 12 years old and one of around 1000 students here. most of them are children from the neighborhood. some had fled the violence but have since returned, like mariam. mariam: my family left timbuktu in 2012. we lived in a refugee camp in mauritania. life was very hard there. we didn't have a proper house, just a hut. it was very windy and very hot in the camp. it was hard. reporter: there are up to 100 children in each class. mariam's teacher abdoulaye bakaye says the returning

refugees need extra special attention. abdoulaye: we have to work with them on two levels. on the one level we have to support them psychologically because so many of them are traumatized. on the other, we have to give them extra tutoring so they can catch up with the otheher pupi. many of the refugee children have missed an awful lot of school. reporter: there's not just a shortage of schools in timbuktu, but also of teaching staff. teachers have to contend with threats from the islamists who want to stop non-religious education. few children here are getting the chance to finish their schooling. mariam: i'm really happy. there's a proper school here with desks, teachers, and books. i'm so glad i have the chance to learn here.

host: an 8000-kilometer-long belt of trees stretching along the edge of the sahara from mali through niger to ethiopia. that's's the goal ofof great gn wallll project. the idea is s that the plalantsl prevent furtrther desertififica, makeoils m me fertile, and reduce conflict. and d it's urgentltly neede. bamakoko in mali, for r insta, has s a booming populationanad dedeforeation n inhe regioio contntinues. reporter: charcoal is big business in bamako, the capital of mali. almost everybody needs charcoal to cook with, and the population is growing. maimuna traoré is a charcoal merchant. she is doing well, but her very success is becoming a source of concern. maimuna: there are fewer and fewer trees. it is scary.

if you go out of town, you will see what i mean. reporter: an australian agronomist with the ngo world vision, tony rinaudo, has developed a method of countering the deforestation that affects large parts of africa. his work won him the right livelihood award, also known as the alternative nobel prize. totony: as land is clearared oe vegetation, the land gradually degrades and become less and less productive. less can be grown on it and less profit can be made from it and people become more desperate. so, ththere is a very strong lk between conflict and land degradation, and also between migration and land degradation. reporter: maimuna traoré tells rinaudo that she now has to get her charcoal from 160 kilometers away because sources closer to bamako have dried up. it's a similar situation in and around many of africa's big cities. the disappearance of forests and

degradation of the land is a huge problem. tony: how do we tackle that? fortunately, through farmer scalable method to reverse that degradation. reporter: in the 1980's, rinaudo discovered that in many places there are intact underground networks of roots struggling to grow, and that pruning shoots can help trees and bushes flourish. world vision is now promoting the f.m.n.r. technique in 24 countries around the world. in yameriga in northern ghana, samuel bantang was among the first farmers to adopt it a decade ago. samuel: it has changed so much in my village. we used to have to drive our cattle long distances to graze. and thieves could steal them. but now they can graze nearby.

reporter: but there's a lot still to do. the villagers regularly go out and work on reviving areas of degraded land, applying rinaudo's technique, and trim new shoots growing out of old stumps. farmer managed natural regeneration isn't complicated. it involves targeted pruning and protecting of new growth. still, it's very effective. these saplings will hopefully grow into tall trees. samuel: we cut some shoots but leave the bigger ones, just one or two. what we cut away we use as firewood. reporter: the key advantage over planting new trees is that the roots are already there and reach deep into the soil. so even if it rarely rains, they can tap into the groundwater. trees can also raise the water table, release moisture into the

air, and fertilize the soil when their leaves fall and decompose. as conditions improved, , samul bantang g was able to increase s herd. samuel: it has h helped a lot. life used to be much harder. but now things are different. we have a proper income, we can look after our families, pay for health insurance and school fees. and everybody has enough to eat. reporter: in yameriga, 82 hectares of land have so far been reforested. but large stretches still look like a desert. dedegraded dryland regions may have countless intact tree root systems that could yet yield new trees, if they are properly tended. rinaudo organizes conferences across africa on f.m.n.r. also in countries that are in turmoil, such as mali. he was recently in bamako.

rinaudo has devoted his life to restoring africa's forests. he says regenerating local vegetatition improves ththe livf millions. and giving people hope can help transform the political landscape as well in many a country. tony: it would transformrm the whole cocountry, because it hs that potential. people t to be able e to be self-sufficient on their own land, they are not going to be so intererted in joioining a fit somemewhere else. they have families to raise, they have aspirations on how they w would like to l lead tr life.. rereporter: cities such asas bo consume vast amounts of natural resources, even as they become ever more scarce. the restoration of vegetation around cities and elsewhere can improve people's quality of life, and perhaps reduce the potential for violence and conflict. host: of thehe world's 68.8 million displaced persons, by

far the majority, around 40 million peopople, are internaly displaced. in colombia, years of paramilitary violence has led to 7.7 million people there suffering that fate. most have nothing to return to. their homes and livelihoods are all gone. and more recently they've been joined by 1.5 million refugees from crisis-stricken venezuela. reporter: bogota is growing fast. some 10 million people live here. but it's the poor districts on the outskirts that are increasing most rapidly. many people displaced from their hohomes elsewhwhere in colombibe settled in soacha. the neighborhood is known to be dangerous, but it's close the city center and rents are cheap. carlos doesn't want to be recognized. a month aghehe fled om g gang warfare in the towofof el rra. carlos: it w warar, we left so as t toto g caught up in ththfighting

if we hadn'teft,t, iwould have costst uour lilis. reporterthe powevacuum lt by the fc is noweing fild oththerroups. anne who dsn't't p protecon moneyets murded. carlosaw 28 pele die bore heecided tflee to e capital. rlos: i feel goohehere. ve had a lot of pporort om the red oss and om victim pporort.hank god i'm ok. ey're heing me fina job in companan th's my pl, to find work a end d threst of my life bogota porter: e hope oa job an a home has also o driven thousus of venezuelalans to colombmbia. venezuzuela closed t the offil bordrder cssingsgs ifebruaryry but families continue to com acro elslsewhere on fofoot. >> therere was nothingng back . noing g for baby,y, nhing foror

us. that's no way to live. no medicinine, no food, , noth. reporter: but things w't't be easysy in combia, either. to get a work permit, yoyou ned proper i.d.d. almost half the venezuelans who've come here don't have that. many are exploiteded as y laborers. some just hahang around e ststreets anbebeg for ney y ad food. even peoplple with a jobob haa hard time finding a decent place to stay. many of those who make it here sleep in so-called "paga-diarios" -- shared rooms packed with beds. they have no rights there and could be evicted at any time. luisis is a hairdresser and haa job, but he barely makes enough st to pay y for his bed. luis: it's likike a prison. we are like prisoners. there are three bunk beds per room. that's six people. so you have absolutely no privacy. and you can't leave any valuables there either.

reporterer: colombia i is tryio copepe with its owown displacedd pepeople and manany more frm venenezuela. the ununited nationsns refugee agency unhcrcr is worried d thae country cannot handle the ststrain. jozef: in rious parts s of colombia, venezuelelans ju sleep on the strtreets, which makekesh vulnererableo attack.. there are all kinds of people.. lotsts of women wiwith childn, pregnant women, older wowomen, d people whoho need speciaial c. ththat's why thehe unhcrcr andr agencies arere trying to a at t offer someme initial help. we wanant to give ththem a chano build a life here in colombia as long as theyey can't retururno venezuela. reporter: this m man is one of e succccessful ones. hehe has opened d a venezuelanan reststaurant in bobogota.

back home hehe worked in t tou, but thenen things becacame unbeararable. carlos: at first i waslalanning toto go ck whehen thregimeme fe. but now w i have my bubusinesse and mymy fily. i'll have to thihink about it. i'llll probably wawait a while.. reporter: ththe restaurateteura role model f for some othehr venezuelans s in colombia,a, t just for hisis success, bubualo because he provides them a tas of he. host: an amazing 85% of all refugees worldwide are taken in by developing countries, regions where poverty and hunger are already key problems. industrialized nations make up just one in ten of all host countries. and one of them, japan, is notoriously tough when it comes to asylum.

kim: the detainees a are treatd worse than animals. perhaps better than insects, but only just. reporter: tokyo, capital of one of the most homogenous societies in the world. foreigners make up only 2% of japan's population. it's also one of the countries most closed to outsiders. more than 10,000 people applied for asylum here in 2018. but only 42 were granted a refugee status. eri ishikawa's organization says it takes care of 600 to 700 asylum seekers every year, helping them fill out applications and survive the long wait. eri: the a asylum process is vy strict. we see the applicants here and we think that more should be accepted.

reporter: her ngo provides applicants with food, accommodation, and clothing during their wait, which averages almost 1.5 years. but its capacities are at the limit. eri: since last year, the government has made the conditions stricteter for work duringhe waiaiting pereriod, o very few people can get work and only a few get government support. reporter: the japanese government says many applicants come for economic reasons only. but documents from the department of justice show that in recent years, only one third of all applicants were clear economic migrants. of all the industrialized countries, japan has the most rigorous interpretation of the u.n. refugee convention. applicants must be able to prove they are threatened in writing and in japanese. during the waiting period, many are at risk of becoming homeless, or if their initial application is denied, they may end up in detention pending

deportation. one of the biggest detention centers is two hours outside of tokyo. kim: the building back there, that's where i was held. reporter: kim eui jung applied for asylum in 2010. decades after being involved in anti-government protests i in south korea, he had rereason o fear repercussions. after overstaying his visa, he spent more than 2.5 years in the center. now he is out on probation. kim: notot much gets out about e condnditions in ththere. after six months, most people's faces turn expressionless. rereporterer: the inmates s han on hununger strikeke several ts in recent yeyears. they criticize the crowded accommodations, insufficient medical care, and the

uncertainty about their status. some are confined for more than five years, although detention is only meant to be temporary. one former detainee is this refugee from sri lanka. he doesn't want to give his name for fear of being recognized in his homeland. in sri lanka, he got caught between the fronts of the civil war. he fought for overer 12 years o gain refugee status. >> i came here when i was 45. now i am 58, 60 now. so, all that time is finished. i can't go back. it's like a punishment. now i don't have my children with me. i don't have my wife with me. and there is no future plan. reporter: thisis mountain of papers is only part of his long-running legal battle. on a stopover to canada, he was detained at the airport in japan for missing documents. it was only in january this year

that he was finally recognized as a refugee. he was helped by people like kyaw kyaw soe. originally from myanmar, he is one of the few refugees who have become successful in japan. 17 years ago he opened a burmese restaurant in tokyo. kyaw: deportation is very difficult, so they do everything they can to make life in japan hard in the hope people who sought refuge here will leave the country voluntarily. the japanese don't want these problems around them. they want to keep them far, far away.

host: at the height of the eu's migration crisis in 2015, many refugees who arrived in germany from regions in turmoil, like syria, received a warm welcome. up to eight million germans volunteeeered to give language classes,s, assistance, and advi, all ofof which helped many youg arrivals settle in. reporter: a fellowyryrian has open a superermarket in hahanov. that is worth a sty y for th photournalalisnajem alalhalaf. hehe's documenting how p peoplo had toto flee syria a try to ma life for themselveinin germa. najem: this is okra. it is quitite rd to fifindere. thisiss from syria. it tastes rereally good wiwith

tomatoes and pepper. reporterer: many germamans dot engage witith the migranants or rerefugees in their midst. najem would like to awaken an interest in syrian culture, including the food. najejem: i try to o show that s not somethining d. on the conontrary, it cocoulde gogood for you, , too. maybe e you will finind it ta. try it. . i am open-miminde. i haveve eaten germaman schnil and d stuffed cabbbbe. i've tried it all. rereporter: whenen he was 18 d studying political scicece and jourlism i in banon, h he was detainined crossing g into syrid tataken a sececreservice e il where he was tortured. th he e was ven a a chce -- join the army or have your familyuy y your eedom,m, wch th d did. aftethat, , henew he h h to leave.e.

najem: s syria was thehe place e i lived d and grew up,p, but itt alien. it wasas not the rigight placer me. i just cld not stathere. reporter: in 2014 he reach germany y overland throuough e babalkans. he experienced so much along t y, b but d not y yetave thee means to r record what h he s. once here,e, he learned d ger, took preparatory classesanand is now udyingng photojournanasm in hanonover. he i is involved with a meaa collllective therere cled camee once a a week, the t team meeto discuss s projects. articles.. al khalalaf hopes he c can soonw his latetest works thehere. lotsts of the storories on t webse arare about the e conceptf identity and the many ways of thinking about it, also with

rerespect to genender and migrg. texts are e in gman, e engsh, and arababic. contributorsrs from all what we believe is that e e plus one e equa threeee when people with diffeferent pointsf viview a backgkgrods cocome together, t that's when, surprising, , and intereststing things emerge. reporter: for najem al khalaf, cameo offersrs a forum foror explploring the isissues closo his heart, free of the coconstrais ofof a me conventional p publication. the lalatest issue o of cameo's magazine is devoted tohehe theme ofof ankommen ---- arriving. al khalaf cocontributed a a pe with phototos of young r refus who talklk about theirir livesa hopes.s.

reporter: al khalaf says h els s goodn germrman but t it's his prorofession tt gives his life focus and meanining. najem: arriving is not necessily y aboureachihing certn spspot tlive i in. ititan also be about fdiding a plplace for yoseself. it'sot alwlwayabout hahavi a new home or r a new languauage. it c can jt be a a fling, finding yourur placen pursuing a orort, forxampmple. oror real placace. ththe feeling ofof having arrd can be very gratifying a othihingor the soul. reporter: : najem al khahalaf s he wilill be alloweded to stan we're back next week. and here's a quick reminder to

send us your feedback. write to global3000@dw.com, and you can find us on facebook, too, dw women. see you next time. ♪ [captioning performed by the national captioning institute,

announcer: on this episodede of "earth focus," ocean acidification caused by global warming is dramatically affecting marine life. in california, partnerships are forming between cocommercial fisheries, scientists, and community members to helelp the endangered abalone adapt and survive. [slide projector clicking] different announcer: "earth focus" is made possible in part by a grant from anne ray foda