Fifteen years years ago the villages around Abrha Weatsbha in northern Ethiopia were on the point of being abandoned. The hillsides were barren, the communities, plagued by floods and droughts, needed constant food aid, and the soil was being washed away.

Today, Abrha Weatsbha in the Tigray region is unrecognisable and an environmental catastrophe has been averted following the planting of many millions of tree and bush seedlings. Wells that were dry have been recharged, the soil is in better shape, fruit trees grow in the valleys and the hillsides are green again.

The “regreening” of the area, achieved in just a few years for little cost by farming communities working together to close off large areas to animals, save water and replant trees, is now to be replicated across one sixth of Ethiopia – an area the size of England and Wales. The most ambitious attempt yet to reduce soil erosion, increase food security and adapt to climate change is expected to vastly increase the amount of food grown in one of the most drought- and famine-prone areas of the world.

“Large areas of Ethiopia and the Sahel were devastated by successive droughts and overgrazing by animals in the 1960s and 1970s,” says Chris Reij, a researcher with the World Resources Institute in Washington.

“There was a significant drop in rainfall, people had to extend the land they cultivated and this led to massive destruction and an environmental crisis across the Sahel. But the experience of Tigray, where over 224,000 hectares of land has now been restored shows that recovery of vegetation in dryland areas can be very fast. Tigray is now much more food secure than it was 10 years ago. You really see the changes there,” he says.

Rather than just plant trees, which is notoriously unreliable and expensive in dry land areas, the farmers have turned to “agro-ecology”, a way to combine crops and trees on the same pieces of land.

A trailer for a new documentary by film-maker Mark Dodd on the land restoration project in Tigray.

In Tigray it has involved communities building miles of terraces and low walls, or bunds, to hold back rainwater from slopes, the closure of large areas of bare land to allow natural regeneration of trees and vegetation, and the widespread planting of seedlings.

“The scale of restoration of degraded land in Tigray is possibly unmatched anywhere else in the world. The people ... may have moved more earth and stone [in recent years] to reshape the surface of their land than the Egyptians during thousands of years to build the pyramids,” says Reij.

“In the early 1990s every able-bodied villager in Tigray had to contribute three months of labour to dig pits to save water, or to construct terraces and bunds to stop water rushing off the hills. This was reduced later to 40 days a year and currently it is 20 days a year.

“Several hundred thousand hectares are now under ‘exclosures’ - degraded areas in which no cutting and grazing is permitted. This allows the natural regeneration of vegetation. Tens of thousands of kilometres of rock bunds and terraces have been constructed, often on steep slopes,” he added.

Ethiopia’s pledge to restore a further 15m hectares of degraded land was the largest of many made at the end of UN secretary general Ban Ki-moon’s New York climate summit last month, where governments, companies and civil society groups together agreed to try to restore 350m hectares of deforested landscapes - an area the size of India - by 2030.

Almost all vegetation has been lost from this hillside due to deforestation and overgrazing from cattle. Photograph: Aaron Minnick/WRI

Commitments have now come from Uganda (2.5m hectares), Democratic Republic of the Congo (8m hectares), Colombia (1m hectares), Guatemala (1.2m hectares), and Chile (100,000 hectares). Many others are expected to follow in the run-up to the Paris climate talks in December 2015 because the restoration of degraded land is expected to qualify for carbon credits.

Africa, with help from the World Bank, the UK government and development groups like Oxfam and World Vision, has emerged as the leader in restoring the world’s estimated 2bn hectares of degraded lands.

According to Reij, a quiet revolution has seen over 200m trees planted and 5m hectares of degraded land regreened in Niger. The result, says a report by the International Food policy research institute, has been extra 500,000 tonnes of food grown in the country with the fastest growing population in the world, as well as an increase in biodiversity and incomes.

In Burkina Faso where 2-300,000 hectares of land has been regreened, food production has grown about 80,000 tons a year – enough to feed an extra 500,000 people.

“There are a lot of inspirational examples in Africa. In Tanzania 500,000 hectares of land has been restored. What this shows is that well-managed ecosystems are good for biodiversity as well as for food security, water supplies and climate change,” said Stewart Maginnis, director of International Union for Conservation of Nature’s (IUCN) nature-based solutions group in Geneva.

Increasing the rate of restoration of degraded lands will be vital both for feeding fast-growing populations and adapting to climate change, says Green Belt Movement (GBM) international director, Pauline Kamau.

“Africa is already experiencing some of the most dramatic extreme temperature events ever seen. Without action to reduce emissions, average annual temperatures on the continent are likely to rise 3-4C by the end of the century and [there could be] a 30% reduction in rainfall in sub Saharan Africa.

“We know that regreening could be a key part of the solution to these problems. Agriculture, forestry and other land use changes accounts for nearly 25% of greenhouse gas emissions globally. Restoring degraded lands can both help rein in warming and adapt to higher temperatures,” she said.

