Development challenges to Africa including droughts could be taken as opportunities for green economy in the continent, the United Nations Economic Commission for Africa (UN-ECA) said on Saturday.

Losses of biodiversity, droughts, reduced agricultural yields, depleted cereal stocks and the multiple demands on existing stocks for biofuels could provide opportunities for Africa to respond to these challenges in the context of a green economy, the UN-ECA said.

The comments were made in the "Africa Report on New and Emerging Challenges" prepared in collaboration with the African Union, the African Development Bank, the UN Development Program, and the UN Environment Program, and circulated at the ongoing UN Conference on Sustainable Development (Rio+20) in Rio, Brazil.

Africa is home to about one quarter of the internationally recognized biodiversity hotspots whose resources are sustaining the livelihood of millions of people in Africa, the report said.

It said two-thirds of the population in sub-Saharan Africa relies on products from the forests in the region, adding wild resources and non timber forest products provide up to 35 percent of rural household incomes in Zimbabwe and over 50 percent in Senegal.

"Addressing biodiversity loss requires permanent and long-term solutions in the form of development and implementation of appropriate policy guidelines, institutional capacity-building and deployment of adequate resources to halt and reduce the intensity of biodiversity loss," said the report.

The water scarcity challenge is already addressed by the Africa Ministerial Council on Water (AMCOW), the Africa Water Task Force, the Africa Water Facility, trans-boundary river basin programs, water sector reforms and Integrated Water Resources Management principles, it said.

While these measures have resulted in some increase in the proportion of population with access to clean water, interventions are more concentrated in urban areas, it added.

According to the report, over 40 percent of the population in sub-Saharan Africa do not have access to clean drinking water and less than 4 percent of Africa's water resources.

Land areas are developed for irrigation despite the huge demands exerted by growing industrial development and urban populations which continue to put pressure on governments.

"It is projected that many countries in Africa will suffer from water scarcity and water stress by the end of the next decade as a result of population growth, industrial development and the associated increases in water demand," the report said.

Of the 1.4 billion people without access to electricity worldwide, 40 percent are in Africa and almost entirely in sub- Saharan Africa.

Improving Africa's access to sustainable energy would facilitate development and contribute to the achievement of some MDGs, especially those pertaining to halving extreme poverty, reducing hunger, reducing child and maternal mortality, promoting gender equality and reducing deforestation, the report pointed out.

"These new and emerging challenges provide opportunities including potential growth in the context of a green economy, utilizing the largely untapped natural resources that are being discovered in many African countries," it said.

The opportunities presented by the new and emerging challenges could reorient Africa on the path of sustainable growth and development, the report said.

To maintain the momentum in the implementation of sustainable development programs, the report said, countries should mobilize and increase the effective use of available financial resources, while exploring ways of generating new public and private innovative sources of development finance.

It also calls for the promotion and facilitation of access to environmentally sound technologies and for the use of ICT to increase the frequency of communication and the sharing of experience and knowledge.