>> today on "earth focus"... restoring the earth, shaping the future. john liu on solutions from china, ethiopia and rwanda. coming up on "earth focus." [drumming] >> this is china's loess plateau. until recently, this was one of the poorest regions in the country. a land renowned for floods, mudslides and famine. but with the fanfare comes the hope of change for the better.

my name is john d. liu. i've been documenting the changes on the plateau for 15 years. i first came here in 1995 to film an ambitious project where local people were constructing a new landscape on a vast scale. transforming a barren land into a green and fertile one. the project certainly changed my life, convincing me to become a soil scientist. the lessons i've learned in the last few years have made me realize that many of the human tragedies that we regularly witness around the world, the floods, mudslides, droughts and famines, are not inevitable. here on the loess plateau i've witnessed that people can lift themselves out of poverty. they can radically

improve their environment. and by doing so, reduce the threat of climate change. >> [singing] >> when i first came to the loess plateau, i was astounded by the degree of poverty and degradation. and i wondered, "how could the chinese people, the largest ethnic group on the planet, and my fathers, and my own ancestors come from a place that was this barren?" china's loess plateau is a region that stretches for 640,000 square kilometers across north central china. unspoiled valleys in neighboring sichuan show us how it might once have looked. it's the sort of natural abundance that is necessary to support

an emerging civilization. how could a landscape with such potential have been reduced to this? when chinese scientists and civil engineers began to survey the area, they realized that several thousand years of agricultural exploitation had denuded the hills and valleys of vegetation. the relentless grazing of domestic animals on the slopes meant that there was no chance for young trees and shrubs to grow. the rainfall no longer seeped into the earth, but simply washed down the hillsides, taking the soil with it. over millennia, this progressively destroyed the region's fertility.

when this happens over an area as extensive as the plateau, millions of tons of silt are swept down into the yellow river, which gets its name from the color of the fine loess soil. the mounting quantities of silt clog up the river, impeding its flow, contributing to the floods that give the river another name: china's sorrow. in some areas, creating floating mud mattresses that attract passing tourists, a local problem becomes a national problem. in the dry season, the light unprotected soil is swept up in the winds, causing the dust storms that are blown over china's cities and beyond its borders.

on the plateau, the researchers realized that progressive degradation of the environment trapped the local population into a life of subsistence farming. it's a process that has occurred throughout the world where poor agricultural communities find themselves overusing their land in order to survive, depleting its fertility and further impoverishing themselves. one thing that became apparent early on is the connection between damaged environments and human poverty. in many parts of the world, there's been a vicious cycle. continuous use of the land has led to subsistence agriculture. and generation by generation, this has further degraded the soils. the vital question we have to ask is, can this destructive process be reversed? [indistinct announcements] 15 years ago, chinese and international experts were confident it could be.

they decided that to prevent further erosion, it was necessary to cease farming on certain key areas to allow the trees and shrubs to grow back. but this could not happen without the consent of the farmers themselves. >> [speaking in chinese] >> they took some persuading. what eventually convinced the local people was the assurance that they would have tenure of their land, that they would directly benefit from the effort they invested in the new project. >> [speaking in chinese] the goal was to give a hat to the hilltops, give a belt to the hills, as well as shoes at the base. the hat meant that the top of these hills

had to be replanted with trees. the belt meant that terraces had to be built to be used for crop planting, and also for trees. the shoes were the dams which we had to build so that the hills could grow back to life, and our economy, as well as our lives, could improve. >> hills and gullies were designated as ecological zones to be protected. farmers were given financial compensation for not farming on them, and keeping their livestock pinned up. when i first filmed mr. ta fuyan and his colleagues back in 1995, i had no idea this initiative could achieve such dramatic results.

the effort that people put into converting their slopes into terraces has resulted in a marked increase in agricultural productivity. the higher yields are directly related to the return of natural vegetation in the surrounding ecological land. now when it rains, the water no longer runs straight off the slopes. trapped by the vegetation, it sinks into the ground, where it is retained in the soil, taking weeks and months

to gently seep down and irrigate the fields and terraces below. restoration has occurred over an area of 35,000 square kilometers. the impact of such an enormous addition of vegetation goes far beyond the plateau itself. there's been a significant reduction in the soil rushing down into the yellow river. as i've been traveling around the loess plateau, i've seen extensive changes. the vegetation cover on the hillsides, on the tops of the hills, and down in the valley, everything has changed. it's changed the lives of the people, and in fact, the people themselves have done this because they were the ones who-- who changed their behaviors,

terraced the fields, improved the soils, learned to protect the marginal areas. the changes are not simply on the hillsides. on the plains, you can see greenhouses that are filled with vegetables. this extends the growing season. it's a very high value produce. the abundance and variety of new produce can be seen in the local markets. follow-up studies have shown that incomes have risen threefold. and scientists point to a more global benefit. plants, through photosynthesis, remove carbon from the air, countering the effect of human greenhouse gas emissions on the climate.

as a result of its success, the lessons learnt from the loess plateau rehabilitation are now being applied all over china. but could such projects work elsewhere in less centrally controlled societies, with fewer resources and different soils? ethiopia, perhaps more than any other country, has come to symbolize the vulnerability of humankind to environmental catastrophe. this is a country whose problems have been increased by war and civil conflict. and now human-induced climate change is predicted to make matters worse. as on the loess plateau, centuries of subsistence farming practices have stripped the land of natural vegetation. the dry gullies bear the scars of flash floods.

these gullies are evidence of the enormous power of run-off during the rainy season. without vegetation cover on the hillsides when the rains come, the water doesn't soak into the ground but flows away in a flood, then it's not available for agriculture during the rest of the year. this leads to drought, and famously for ethiopia, famine. but just as i witnessed in china, there is hope that the situation here can be reversed. in just six years, professor legesse negash and local villagers have transformed a severely eroded terrain by planting indigenous trees and plants. almost miraculously, a clear flowing stream has emerged where once there was a muddy trickle. how is it that it's possible for you to get the stream

to flow throughout the year? >> it is because of the vegetation cover, which has been regenerating on this mountain. this water is maintaining the landscape because as soon as rain falls on the canopy, on this vegetation, that rain then infiltrates gradually to the ground, ending up with this steady flow of this river. water is life. without water, nobody can do anything. i'm amazed as short as five years--six years, you get clean water like this provided you work hard for restoring this degraded landscape. >> about a 1,000 kilometers further north in the village of abraha atsbeha, another near miraculous phenomenon is occurring. farmers are finding water at the bottom of their wells,

despite the poor rains this year. the famine of 1984 struck the people of this valley very hard. many migrated, many died. now the people are returning. the village chairman, gabre giday, remembers well how life used to be. >> [speaking in foreign language] ten years ago i'd say, even five years ago, i'll tell you what the situation was: it was absolutely terrible. the sun, the drought, the wind, it was all dry like the desert. there was a refugee program for our village, so we had a choice, leave the valley or do something. >> with government support, they applied the same principles as the chinese: setting land aside for natural vegetation to return.

in the ravines, they built small dams which are now fed by underground springs. and like professor legesse's stream, rain that fell weeks ago now slowly seeps through the subsoil, replenishing the supply of water. >> [speaking in foreign language] the eroded land has become fertile, it's changed for the better. in the drought, our fruit trees dried up. now they are coming back, and we're growing even more varieties. these are the real benefits we've seen. we have food security, and our children can go to school. our lives have improved. >> these villagers are now better able to withstand the impact of climate change.

with international assistance, their achievement could be repeated across the country. the benefits, as professor legesse points out, would spread far beyond ethiopia's borders. >> the most important issue for africa, and i consider this africa's 21st burning issue, is restoration. no matter what we do, we might be good at rocket, uh, rocket uh, rocket science, i mean, nuclear science. but the environment, restoring this huge vast landscape, you know, degraded landscape is critical for africa, particularly for ethiopia. you know, half of ethiopia is mountains, and this mountain system is degraded, and this degradation of this huge landscape, huge mountain chain of ethiopia is critical not only for ethiopia, but also for the entire region. consider egypt,

look at the sudan, where six percent of the nile flows to these countries. how can you support life in egypt without restoring ethiopia's mountains? so this is regional, national, and international. >> environmental degradation is not only a problem for the dry regions of ethiopia. it can be just as devastating for countries like rwanda, where rainfall is plentiful. this tiny country is grappling with the problem of a growing population trying to eke out a living on a finite amount of land. as in china and ethiopia, over-farming on the hillsides caused serious erosion and a decline in fertility, forcing poor farmers to move into protected areas, such as the rugezi wetlands, a wildlife site of international importance.

when farmers drained this marsh to try to grow more food, they not only damaged an important wetland ecosystem, they also had a significant impact three hours drive away in kigali, the capital city. the water that pours from the marshlands is a vital source of hydro power for rwanda's capital. as the wetlands began to dry out, power stations below couldn't generate enough electricity. the rwandan government rented diesel-powered generators to make up the shortfall. doctor rose mukankomeje took me to see them. >> so what is happening here is that those generators... we are renting them from this company, and we are being obliged to rent them, especially, when we degraded the wetlands and we lost 20 megawatts of electricity, and to run

those machines we are paying 65,000 u.s. dollars a day. >> $65,000 a day, that's multimillions of dollars per year. >> yes, it millions of dollars and, as you must--might know, rwanda is not a rich country. some of that money has been borrowed from the bank, as from taxpayers. >> how does this affect the climate? >> of course, those machines, they run on diesel, and when you're burning diesel, you are producing greenhouse gases. >> environmentally damaging and more expensive, locals had to pay three times as much for their electricity. so government policy makers focused on how to restore the rugezi wetlands. if people were the problem, they could also be the solution.

the government decided to help the farmers leave the wetlands, and to restore the degraded slopes above them, improving their croplands and encouraging trees and shrubs to grow back, capturing the rain. >> we have been supporting them by doing terraces, specifically there on the hills where they can increase and improve the productivity. the most important thing is to have people with you, on your side. >> the wetlands are now recovering. great volumes of water once again cascade down to power the hydro stations. carbon-free electricity is replacing the diesel generators. electricity prices have stabilized.

restoring and preserving natural ecosystems like the rugezi wetlands, benefits everyone, and so much more could be achieved. >> if we had more involvement by different institutions coming in to help, we'd have better resources, rwanda could do more, much more, and benefit much more, but so would other countries if such partnerships and support were provided. >> what the rwandans recognized is that the marshlands are far more valuable as a natural system providing water for energy than as farmland. this principle is the same for the remaining hillsides and ravines. what we are seeing here is very interesting because it's a line between human activity and natural systems. and in the human activity,

we've been able to value the productivity from agriculture and give it a monetary value, but in the natural systems, we haven't been able to value the trees, the biodiversity, the water that's absorbed into the biomass and into the soils. and there's another vital service that trees and plants provide: photosynthesis. vegetation reduces the greenhouse effect by taking carbon dioxide out of the atmosphere. a measure of what restoring nature can do has been shown here on china's loess plateau, where farmers have continued to prosper despite the worst drought in decades. >> [singing] >> since the beginning of the project, the soil

that nurtures their crops has been accumulating organic material from plants and animals. this holds the moisture and contains carbon. what's interesting about this is all these root materials, all this other stuff, this is organic material. and this organic material is mixing together with the loess, the geologic soils here, and is making a living soil. this is where the moisture resides. yesterday it rained and there's still moisture in the soil. this is where the nutrients are recycled so that each generation of life emerges here. and this is where the carbon is. what's interesting about this, they made this field, this is new, so they're helping to sequester carbon. living soils like this retain on average three times more carbon than the foliage above the ground. if we were to restore the vast areas of the planet

where we humans have degraded the soils, just think what an impact we would have in taking carbon out of the atmosphere. as much as a quarter of the world's land mass has been degraded. and much could be rehabilitated in the way we have seen on the loess plateau. and we've only just begun to recognize the real value of natural capital. surely, investing in the recovery of damaged environments is a cost-effective way of solving many of the problems we face today. >> why do we not invest an equal amount, if not more, into a shovel-ready technology, so to speak, which is nature's way of sequestering and storing carbon? it is actually by investing in our ecological infrastructure and ecosystems, and expanding the ability of nature to sequester and store carbon, that we have the greatest opportunity to do something, and the wonderful thing is it's not only

carbon sequestration, we are also faced with loss of ecosystems that will affect our food security, our water security, we are losing species on an unprecedented rate. so maintaining, restoring, protecting, expanding, natural ecosystems has multiple benefits. >> my hope is that the developed countries, those most responsible for climate change, will recognize the enormous potential of restoration. what we've seen in china, in africa and around the world is that it's possible to rehabilitate large-scale damaged ecosystems. if we can transfer the capital, the technology and empower the local people to restore their own environment, it'll have enormous benefits. restoration can sequester carbon, reduce biodiversity loss, mitigate against flooding, drought and famine.

it can ensure food security for people who are now chronically hungry. why don't we do this on a global scale? go

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