Will Earth turn as arid as Sahara Desert? Here's what disappearance of grasslands hint at

Cairo, Egypt

After the recent discovery of the possibility of green pastures and grasslands in the Sahara Desert nearly 4,000 years ago, scientists are now trying to understand if the Earth will undergo a dramatic transformation like northern Africa. 

A recent study has explained how grasslands, forests and lakes disappeared and the Sahara desert expanded due to which humans were forced to retreat to the mountains, the Nile valley, the oases, and the delta.

This geographical transition from the "African humid period", which existed from 15,000 to 5,500 years ago, led to the creation of current dry conditions in northern Africa, which scientists are now seeing as the best example of a climate tipping point in recent geological history. 

Also Read: Has Sahara Desert always been barren? A 4,000-year-old rock art holds the answer

Climate tipping points are thresholds which once passed through lead to a dramatic climate change setting up of a new stable climate.

Climate flickering in Africa

According to a new study, which was published in Nature Communications, it was revealed that before the dry out of northern Africa, its climate "flickered" between two stable climatic conditions before permanently tipping.

For the first time, it has been observed that such flickering took place in the past on Earth. For scientists in today's world, the biggest concern is whether humans will get any warnings of climate tipping points.

According to the scientists, after crossing the global warming of 1.5˚C, the most obvious tipping points are the collapsing ice sheets in Antarctica or Greenland, abrupt thawing of Arctic permafrost or tropical coral reefs dying off.

According to some, the Earth is likely to give warning signs of these major climate shifts. However, it will depend on what is the type of tipping point, and hence, it is difficult to interpret these signals.

One of the major questions is if tipping points will be characterised by flickering or if the climate will appear to be very stable before suddenly tipping over.

Watch: Climate change fuels global floods

An international team of scientists to further study the climatic shifts went to the basin of Chew Bahir in southern Ethiopia. 

They found the existence of an extensive lake in this region during the last African humid period. The existence of the lake has been recorded by the deposits of sediment which are underneath the lake bed.

The lake has today largely disappeared and the deposits can be cheaply drilled by the people.

(With inputs from agencies)