(Bloomberg) -- The African Union is expanding a program that aims to plant millions of trees on the continent, despite failing to make significant progress in the decade and a half since it began. 

Launched in 2007, the Great Green Wall Initiative was meant to restore more than 100 million hectares (1 million square kilometers) of degraded land and sequester 250 million tons of carbon in 20 countries, but it has had little success. 

Paul Tangem, the African Union coordinator for the initiative, said climate change, migration, a lack of funding and conflict had all hampered tree-planting efforts in existing areas, but new technology and financing mechanisms offer fresh opportunities in new areas. 

It is almost impossible to work in Mali, Burkina Faso, Niger, Chad, Nigeria, Ethiopia, Eritrea and northern Cameroon due to insecurity and funds being diverted for humanitarian support. 

“We are shifting now to areas that have less security threat and are less conflict prone,” Tangem said. “We are also moving into the southern part of Africa. We realize that Madagascar, Angola, Namibia and South Africa have in recent years suffered serious droughts and desertification. We now have the Great Green Wall extended to them.”

A UN study in 2020 found the initiative had reached about 20% of its target, but Tangem argues it is not just about planting trees. The initiative has created a policy platform for partners to “work together to combat desertification and extreme weather.” 

The world’s least developed continent, Africa, produces just 4% of global greenhouse gas emissions but is already suffering some of the worst consequences of a changing climate. Natural disasters from drought to flooding are becoming more frequent and intense as temperatures and sea levels rise.

Yet rich nations have never met a pledge to funnel $100 billion a year to help developing countries shift toward cleaner energy sources and bolster their infrastructure against extreme weather. 

The new strategy plans to tap into modern financial instruments including nature-for-debt swaps, climate bonds and green bonds to achieve the aims that eluded it before, Tagnem said. 

The project is estimated to cost as much as $50 billion. 

Gabon is one of a handful of countries that have turned their trees into a source of income, recently reaching an agreement under the Central Africa Forest Initiative for its efforts to curb deforestation. 

Lee White, Gabon’s Minister of Water, Forest, the Sea and Environment, said private sector participation will be the key to success. 

“If there was a real ecosystem carbon market out there, then we could mobilize the power of the private sector,” he told an IMF panel on Feb. 7. 

This week, Ethiopia signed an emissions reduction purchase agreement with the World Bank, in part for forest preservation that could see the Horn of African nation receive as much as $40 million.

“We don’t want to reach a point of no return where we have gone off the planetary boundaries,” Tagnem said. “We need to bring back the soils and the communities.”

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