by Tigere Chagutah

The climate change challenge, while serious and urgent, also brings with it enormous opportunities for Zambezi Basin states to advance efforts towards sustainable development.

Although no focused studies on the severity of climate change impacts in the basin have yet been concluded, experts say the recent spate of floods and droughts and increased unpredictability of rainfall leaves little room for delay in implementing mitigation and adaptation strategies.

Climate variability has been observed from season to season throughout the Zambezi River Basin.

A report on “The impact of climate change on the Mosi-oa-Tunya World Heritage Site” prepared by the National Heritage Conservation Commission and the Provincial Meteorological Office in Livingstone, Zambia, says average annual rainfall for Livingstone Meteorological Station has fallen gradually from 1960 to date.

A similar trend has been observed for monthly and daily data while the level of water in the Zambezi River has also decreased over the same period.

The onset of the rain season has become unpredictable while the frequency of long dry spells within the rainfall season has increased across the basin.

This trend has become more pronounced beginning in the 1980s to date according to data collected at the Livingstone Meteorological Station.

A changing climate will affect all aspects of life in the basin in which the majority of farmers depend on rain-fed agriculture for their livelihoods.

Rainfall is the primary source of freshwater in the Basin and most rural communities, who make up the majority, also depend directly on water in rivers, wetlands and lakes for their domestic water supply and income-generating activities.

The report warns that reduced flow in the Zambezi would have serious implications on power generation along the river. About 75 percent of the total hydropower installed capacity in the Zambezi Basin is on the river itself.

A study of the potential impact of climate change on the proposed Batoka Gorge hydro project by experts from the University of Edinburgh found that a reduction in flow levels over the Victoria Falls of 35 percent would cut annual power production by 21 percent and dry season production by 32 percent.

Diversifying from over dependence on hydropower would require emphasis on small-scale and decentralised supply.

The United Nations Development Programme (UNDP) emphasises a “focus on energy options that are easy to implement, involving local capacity and low operational costs.”

These technologies, which include biomass, improved cooking stoves and mini-hydro stations, among others, are more sustainable and easy to deploy widely across the basin.

Besides hydropower generation and irrigation, less reliable water resources will threaten wetlands biodiversity and wildlife among many other economic, social and environmental concerns.

Reduced flow over the Victoria Falls would affect plant and wildlife, but also diminish the visual appeal of the world heritage site impacting negatively on the site's vibrant tourism activities.

While dealing with the adverse economic, social and environment effects of changing weather patterns will require concerted long-term efforts by Basin States, experts agree that there is need to focus more clearly on the multi-sectoral benefits of early action.

A report, “Confronting Climate Change: Avoiding the Unmanageable and managing the unavoidable”, by the Scientific Expert Group on Climate Change and Sustainable Development says the solutions to climate change bring many “win-win” solutions for addressing sustainable development concerns.

Major measures to mitigate climate change include reversing deforestation, reducing greenhouse gas emissions and expanding the use of bio-fuels in the transport sector.

These measures bring benefits, not only in terms of reducing climate change risks, but also in reducing other environmental problems and addressing economic goals, including reduced dependence on imported oil products.

Addressing the UN Commission on Sustainable Development held early May in New York, UN Secretary-General, Ban Ki-moon stressed that turning to renewable energy has many economic, social and environmental benefits.

“We must do more to use and develop renewable energy sources. Greater energy efficiency is also vital. So are cleaner energy technologies, including advanced fossil fuel and renewable energy technologies, which can create jobs, boost industrial development, reduce air pollution and help to mitigate greenhouse gas emissions,” said Ban.

Adopting strategies that move the Basin towards sustainable development goals would lead to improvements in water management and poverty reduction as well as reduced vulnerability to climate change in all sectors.

Measures such as small-scale rainwater harvesting technologies, affordable drip irrigation and treadle pumps would help improve crop productivity at a lower cost than building large dams. 

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