Green Sahara: An Unusual Shift In Weather Pattern Makes The Impossible Possible | What Does It Mean

With the devastating impacts of climate change racing up with every passing day, Africa's mighty Sahara Desert is undergoing an unprecedented transition owing to an unusual rainfall influx. The recently released satellite images by NASA depicted a very noticeable increase of green colour, suggesting unusually increased vegetation, creeping into parts of the desert which geographically represents one of the driest parts of the world.

From plant life growing in the arid region to catastrophic flooding in several other places in the continent- Africa's weather landscape is facing a major change following an unusual shift of a storm zone. Scientists also hold global warming due to fossil fuel pollution highly accountable for the changes.

In accordance with Africa's typical weather pattern, rainfall in north of the equator generally increases from July through September as the West African Monsoon sets in. An increase in stormy weather in general marks the onset of monsoon in Africa.

The focus for this stormy weather, known as the Intertropical Convergence Zone, keeps shifting between north and south of the equator accordingly during the summer months in both the hemispheres.

What changed this year?

However, according to National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center (CPC), in an extremely unusual move, the Intertropical Convergence Zone (ICZ) since at least mid-July has moved towards north further than it actually should.

This unusual shift of the zone caused excessive storms and rainfalls in the southern Sahara across Niger, Chad, Sudan, and Libya and made the arid region twice to six times wetter than they should be.

What caused the shift?

According to a report by CNN, Karsten Haustein, a climate researcher at Leipzig University in Germany cited two potential reasons this strange shift towards the north.

While the first reason took into account the transition from El Niño to La Niña weather pattern, the other reason inevitably was the global warming.

“The Intertropical Convergence Zone, which is the reason for (Africa’s) greening, moves farther north the warmer the world gets,” Haustein explained.

"As the world warms, it will be able to hold more moisture.This could lead to wetter overall monsoons and more devastating flooding like this season", Haustien explained, as per CNN.

In climate science, a shift between El Nino and La Nina, the opposite extremes in the El Niño/Southern Oscillation (ENSO)cycle, often amplify unpredictability of weather patterns.

El Niño, in simple words, is defined as a weather pattern involving abnormal warming of surface waters in the equatorial Pacific Ocean leading to extreme heat in many parts of the world and the ocean.

La Niña, on the other hand, demonstrates the opposite effect of El Niño. During La Niña events, trade winds are even stronger than usual, pushing more warm water toward Asia. Off the west coast of the Americas, upwelling increases, bringing cold, nutrient-rich water to the surface. These cold waters in the Pacific push the jet stream northward. 

Erratic rainfall and floods in Africa

Besides turning the Sahara green, the impact of the shift has also disrupted the Atlantic hurricane season. Consequently, the countries that should be getting more rainfall are getting less as storms shift north.

This year, Nigeria and Cameroon, which typically receive rainfall of atleast 20 to 30 inches between July and September, have only received between 50 and 80 percent of the usual amount, as per reports while the drier areas including Niger, Chad, Sudan, Libya and southern Egypt were inundated with over 400 percent of their typical rainfall since mid-July, said CPC.

In Chad, a devastating deluge triggered by excessive rainfall affected around 1.5 million people while at least 340 have been killed. In Nigeria as well, flooding has killed over 220 people and displaced hundreds of thousands, as per media reports. In Sudan, at least 132 people were killed while 12,000 homes were destroyed.