Scientists uncertain about climate change impact on Nile

One scenario set out by climatologists is that global warming in Egypt could speed up the Nile river evaporation process and lead to a decline in freshwater supplies, exacerbating the country’s acute shortage of water for drinking, irrigation and hydro-electric generation.

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Such a scenario could also have serious socio-economic consequences, one of which could be that Egypt might not be able to feed its 80 million people.

However, experts offer conflicting projections and remain uncertain whether climate change will have such a negative impact on the Nile.

Specialists say Egypt is already facing massive water management challenges due to demographic pressures and rising demand for water and electricity, but it is not clear how climate change will affect future Nile flows, and the key vulnerabilities have yet to be assessed.

Nahla Abou El-Fotouh of the Strategic Unit at the National Water Research Centre in Cairo said scientific studies have shown conflicting climate change scenarios for the future availability of Nile water as a result of global warming and changes in the earth’s hydrological cycle.

Some experts say that there will be water increase with more rainfall from the Ethiopian plateau, and some say there will be a decrease because of water evaporation.

“Some experts say that there will be water increase with more rainfall from the Ethiopian plateau, and some say there will be a decrease because of water evaporation. Until now, no specific research has been developed to determine exactly the impact of climate change on Nile water availability. All [studies] that have been published so far are only predictions.”

A 2004 report by the Organisation for Economic Co-operation and Development (OECD) said a rise in temperature of just one degree centigrade would lead to large evaporation losses and significantly reduce Nile flows, assuming a 4 percent increase in evaporation per degree centigrade rise in temperature.

According to Mohamed al-Raey, a professor of environmental studies at Alexandria University, a large number of studies foresee up to a 70 percent decline in Nile water availability, while other studies project an increase in Nile water levels by 25 percent over current yearly levels due to changing rainfall patterns.

Vulnerable to climate change?

The river Nile supplies 95 percent of Egypt’s total water needs for irrigation, and industrial and economic activities. Most of the population is concentrated on the narrow T-shaped strip along the Nile and the delta coast. The delta makes up only 2.5 percent of Egypt’s land mass but is home to over a third of the country’s population.

The country is, therefore, extremely vulnerable to any adverse climate change impacts on water availability in the coastal zones and the Nile.

Improved methodologies needed

The controversial results show that improved hydrologic methodologies are needed to assess the magnitude of potential future climate change impacts on Nile flows and to design an appropriate public policy.

Photo: Wikimedia Commons

A map showing the River Nile's passage through Egypt

In an attempt to fill this knowledge gap, the UN Development Programme (UNDP), together with the National Water Research Centre and Egypt’s Ministry of Water and Irrigation, have developed the computer software tool Decision Support System for Water Resources, which can produce various climate change scenarios for the Nile basin and therefore improve water resource planning and management.

Mohamed Bayoumi, UNDP environment specialist, said the system would be used “to develop future projections and to get a clear picture of how to use water resources. So if extreme scenarios happen, and whether there is an increase or decrease of Nile water flows, we are already prepared and know exactly what we have to do”.

Contingency measures

While substantial uncertainties remain about how exactly climate change will affect Nile flows through evaporation or changing rainfall patterns, several policies and adaptation measures have been suggested to limit the possible threat of acute water scarcity.

The Ministry of Water Resources and Irrigation’s National Water Resources Plan for Egypt describes how the country can develop additional water sources, implement an efficient water management strategy and protect public health and the environment.

Photo: Wikimedia Commons

No specific research has been developed to determine exactly the impact of climate change on Nile water availability

Options proposed by the OECD include the improvement of rain-harvesting techniques, increasing the extraction of ground water, recycling water, water desalination, and improving accessibility of water reserves.

Abou El-Fotouh of the National Water Research Centre told IRIN: “None of the Nile countries has conducted serious research on the effects of climate change. Most research and initiatives come from Western countries and institutions. But we [Egypt] are planning to initiate deep impact investigations and to find measures to reduce the threat of climate change.”

At the same time, UNDP’s Bayoumi said hydrologic models are currently being elaborated which will give insights into water evaporation from the Nile and rainfall patterns in the Ethiopian highlands and Lake Victoria, the headwaters of the Nile.

“We are elaborating regional circulation models which will give us more prediction on rainfall patterns and Nile water availability. But there is no answer yet. Everything at this moment in time is scientific speculation.”

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