Global warming and overexploitation threaten Africa’s longest river

Global warming and overexploitation threaten Africa’s longest river

The Nile, which stretches from Uganda to Egypt, is essential to the survival of millions of people in Africa. But a combination of climate change and human abuse is drying up the river and worsening conditions for farmers who fear lower yields and loss of electricity.

More than 6600 km long, Nile The basin spans 11 countries, including Tanzania, Burundi, the Democratic Republic of the Congo, Rwanda, Uganda, South Sudan, Ethiopia and Egypt – where hundreds of heads of state gathered to participate COP27: Climate conference in Sharm el-Sheikh starts on Sunday.

But global warming and human overuse are putting the world’s second-longest river under strain. In the last 50 years, the flow of the Nile has decreased from 3,000 cubic meters per second to 2,830. Expected lack of rainfall and increased drought in East Africa mean river flows could drop by 70 percent by 2100, according to UN projections.

The world body predicted that each local resident would lose 75 percent of the available water. Soil erosion, crop loss and lack of electricity can also have a dramatic impact on the millions of people living in Africa who rely on the river for their survival.

“Those with the least water will have less water tomorrow”

At the southern tip of the Nile, the effects of climate change are being felt strongly in Africa’s largest lake. Located between Kenya, Uganda and Tanzania, Lake Victoria is the largest supplier of water to the Nile, except for rainfall. However, evaporation, lack of precipitation, and changes in slope Earth’s core meaning the lake is now endangered.

One 2020 study analyzed historical and geological data from the past 100,000 years and found that the entire body of water could disappear. the next 500 years. This would have a staggering impact on the Nile, a river whose basin covers 10 percent of the African continent and which is an essential resource for the 500 million people living around it.

“Those who have the least water today will have even less water tomorrow because the competition for water will be fiercer,” said Habib Ayeb, a geologist and professor emeritus at the University of Paris-8-Saint-Denis.

Ayb says the lack of access to water for people living along the Nile in countries like Egypt and Ethiopia is already a problem not because of climate change, but because of politics. Priority access is currently given to large agricultural enterprises as opposed to local residents. “There is a lot of competition for water, exacerbated by agribusiness growing produce for export. The policy, which aims to export water from the Nile in the form of tomatoes or cucumbers, does not take into account. [local] a population that needs this water,” Ayb adds.

Climate change threatens to worsen the situation for millions of people. “The lowering of water levels due to global warming will affect those who are already most in need,” says Aybe.

“Invade” saltwater

At the northern end of the Great River, another effect of climate change is being felt in the Nile Delta, the sediment-rich area where the river meets the Mediterranean Sea. This area is one of three locations in the world most vulnerable to global warming, according to the Intergovernmental Panel on Climate Change, as the weakened river flow tries to push back rising sea levels.

Every year since 1960, the Mediterranean Sea has been eroding 35 to 75 meters of land in the Nile Delta. If it rose one meter, it would inundate 34 percent of the surrounding area in northern Egypt, displacing 9 million people.

Depletion of river resources aggravates the problem. “The less water there is in the Nile Valley, the more the Nile Delta will be flooded with Mediterranean water,” says Aybe. This not only brings the risk of soil erosion and flooding, but also changes the composition of the river. “The groundwater layer below the river delta is increasingly made up of salt water from the Mediterranean Sea as less and less fresh water comes in,” adds Aib.

Along the northern banks of the river, the water becomes saltier. “Very little drainage water (fresh water from the river) reaches the Mediterranean Sea. Less than 1 billion cubic meters of water, which is ridiculous compared to what was 40 or 50 years ago,” says Aib.

Already, the salt coming from the Mediterranean Sea has polluted hectares. weakening and killing plants. Farmers reported a decrease in the quality of vegetables.

The situation is likely to worsen. if temperatures continue to rise, the Mediterranean Sea will reach the Nile Delta by 100 meters every year, according to the United Nations Environment Program (UNEP). Over time, it estimates that the Mediterranean Sea could swallow 100,000 hectares of agricultural land that is less than 10 meters below sea level. This will be disastrous for Egypt, where the north of the country accounts for 30-40 percent of the national agricultural output.

To compensate, some try to restore the freshwater balance in their fields by using measures that worsen the overall problem, such as pumping water further down the Nile and building dams.

Cost of hydroelectric power

In the 10 countries through which the Nile flows, the river is not only a source of water, but also of energy. Sudan generates more than half of its electricity resources from hydropower. In Uganda, that figure reaches 80 percent.

But this source of energy is becoming increasingly unreliable. Power outages are already a frequent occurrence in Uganda, says Twinomuhangi Revokatus, a senior lecturer at Makerere University’s College of Agricultural and Environmental Sciences. “If rainfall decreases, water levels in Lake Victoria and the Nile will also decrease, which will reduce hydropower generation,” he says.

In Ethiopia, despite rapid economic growth, lack of access to electricity is a daily reality for half of the country’s 110 million inhabitants. The country’s leadership is working on a massive dam to fix this, even if it means cutting off electricity to neighboring countries.

Construction of the Grand Ethiopian Renaissance Dam (GERD) began in 2011 on the Blue Nile, one of the river’s two main tributaries, with the goal of creating 13 turbines capable of generating 5,000 megawatts of electricity annually. Since August, 22 billion cubic meters of water have accumulated in the reservoir of the dam, the total capacity of which is 74 billion cubic meters.

This makes the structure the largest hydroelectric dam in Africa. However, it is also a source of tension with Egypt, which questions a 1959 agreement between Egypt and Sudan to share the river’s flows, of which 66 percent goes to Egypt and 22 percent to Sudan.

Egyptian leaders fear a sharp reduction in Nile flow if the GERD fills too quickly. Scientists also take sides, with some accused of exaggerating water losses in Egypt to justify possible intervention on Ethiopian soil, while others are accused of minimizing the problem and “betraying” their country.

Farmers in Egypt have already seen the impact of the Aswan Dam, one of the largest dams in the world. As with dams in Ethiopia, Uganda and Sudan, it has reduced the level of silt in the water, a valuable natural fertilizer.

In Sudan, changes like this, along with a lack of rainwater storage and recycling facilities, pose huge challenges for farmers and exacerbate a crisis that has left one in four people homeless. facing severe hunger.

Like other countries along the Nile River, Sudan is located near the bottom of the Notre Dame campus GAIN ratingswhich measure resilience to climate change.

For Caliste Tindimugaya of Uganda’s Ministry of Water and Environment, rising temperatures will not only affect the country’s ability to feed its population, but also to generate electricity for homes and industry.

“Short heavy rains can cause flash floods. Long dry periods will cause water loss,” he said. “And you can’t survive without water.”

with AFP

This article has been translated the original French



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