How climate change shaped societies in ancient Egypt

The Roman Empire’s rise to dominance in Egypt may have been helped by a series of huge volcanic eruptions. 

That’s according to a new study that claims these eruptions reduced rainfall in the country and led to civil unrest.

The unrest may have led to the destruction of the Ptolemaic Kingdom, ruled Egypt and North Africa in the final three centuries BC, paving the way for Cleopatra and the Roman Empire.

 

The Roman Empire’s rise to dominance in Egypt may have been helped by a series of huge volcanic eruptions. That’s according to a new study that claims these eruptions reduced rainfall in the country and led to civil unrest

WHY DO VOLCANIC ERUPTIONS REDUCE FLOODING?

Volcanic eruptions caused reduced flooding by releasing sulphurous gases into the stratosphere, according to the researchers.

These gases react to form aerosols that remain in the atmosphere for up to two years, reflecting incoming solar radiation back to space.

The reduction in surface temperatures can lead to reduced evaporation over waterbodies, and so less rainfall.

Researchers from Yale University examined the climate and societal impacts in Egypt of a sequence of volcanic eruptions spanning the past 2,500 years.

The team focused on the Ptolemaic dynasty of ancient Egypt (305-30 BC) – the state famed for one of its rulers, Cleopatra.

Their analysis involved a vast range of evidence, including annual measurements of Nile summer flood heights from 622-1902 and descriptions of flood quality from ancient writings.

The findings revealed how large volcanic eruptions impacted on Nile river flow, reducing the height of the agriculturally-critical summer flood.

Their analysis involved a vast range of evidence, including annual measurements of Nile summer flood heights from 622-1902 and descriptions of flood quality from ancient writings (pictured)

Their analysis involved a vast range of evidence, including annual measurements of Nile summer flood heights from 622-1902 and descriptions of flood quality from ancient writings (pictured)

Dr Joseph Manning, lead author of the study, said: ‘Ancient Egyptians depended almost exclusively on Nile summer flooding brought by the summer monsoon in east Africa to grow their crops.

‘In years influenced by volcanic eruptions, Nile flooding was generally diminished, leading to social stress that could trigger unrest and have other political and economic consequences.’

Volcanic eruptions caused reduced flooding by releasing sulphurous gases into the stratosphere, according to the researchers.

The analysis suggests that a series of enormous volcanic eruptions caused reduced flooding of the Nile, leading to social stress that triggered unrest (stock image)

The analysis suggests that a series of enormous volcanic eruptions caused reduced flooding of the Nile, leading to social stress that triggered unrest (stock image)

The Ptolemaic era is one of ancient Egypt's most well-documented periods, meaning that the dates of major political events are well known.  Pictured is an ancient wall relief of Cleopatra III, Cleopatra II and Ptolemy VIII in front of eagle-headed god Horus, Kom Ombo

The Ptolemaic era is one of ancient Egypt’s most well-documented periods, meaning that the dates of major political events are well known.  Pictured is an ancient wall relief of Cleopatra III, Cleopatra II and Ptolemy VIII in front of eagle-headed god Horus, Kom Ombo

KEY FINDINGS 

Researchers examined the climate and societal impacts in Egypt of a sequence of volcanic eruptions spanning the past 2,500 years.

The team focused on the Ptolemaic dynasty of ancient Egypt (305-30 BC) – the state famed for one of its rulers, Cleopatra.

Their analysis involved a vast range of evidence, including annual measurements of Nile summer flood heights from 622-1902 and descriptions of flood quality from ancient writings.

The findings revealed how large volcanic eruptions impacted on Nile river flow, reducing the height of the agriculturally-critical summer flood.

The Ptolemaic era is one of ancient Egypt’s most well-documented periods, meaning that the dates of major political events are well known.

The researchers were able to show that many of these events coincided with major volcanic eruptions.

These gases react to form aerosols that remain in the atmosphere for up to two years, reflecting incoming solar radiation back to space.

The reduction in surface temperatures can lead to reduced evaporation over waterbodies, and so less rainfall.

The Ptolemaic era is one of ancient Egypt’s most well-documented periods, meaning that the dates of major political events are well known.

The researchers were able to show that many of these events coincided with major volcanic eruptions.

Dr Manning said: ‘Egypt and the Nile are very sensitive instruments for climate change, and Egypt provides a unique historical laboratory in which to study social vulnerability and response to abrupt volcanic shocks.

‘Nile flood suppression from historical eruptions has been little studied, despite well documented Nile failures with severe social impacts coinciding with eruptions in 939, in 1783-1784 in Iceland, and 1912 in Alaska.

‘With volcanic eruption dates fixed precisely in time, we can see society in motion around them.

Volcanic eruptions caused reduced flooding of the Nile (pictured) by releasing sulphurous gases into the stratosphere, according to the researchers

Volcanic eruptions caused reduced flooding of the Nile (pictured) by releasing sulphurous gases into the stratosphere, according to the researchers

PTOLEMAIC DYNASTY

The Ptolemaic dynasty controlled Egypt for almost three centuries (305 – 30 BCE), eventually falling to the Romans.

But while they ruled Egypt, they never became Egyptian.

Instead, they isolated themselves in the capital city of Alexandria, a city envisioned by Alexander the Great.

The city was Greek both in language and practice.

There were no marriages with outsiders; brother married sister or uncle married niece.

In the end, even Cleopatra VII remained Macedonian.

Except for the first two Ptolemaic pharaohs, Ptolemy I and his son Ptolemy II, most of the family was fairly inept and, in the end, only maintained authority with the assistance of Rome. 

‘This is the first time for ancient history that we can begin to talk about a dynamic understanding of society.’

The researchers believe their findings could be applied to what is happening today with climate change.

Dr Manning added: ‘The study is of particular importance for the current debate about climate change.

‘There hasn’t been a large eruption affecting the global climate system since Mount Pinatubo in the Philippines in 1991.

‘We are living in a period where we are fairly quiescent in terms of large volcanic eruptions that are affecting climate.

‘A lot of volcanoes erupt each year but they are not affecting the climate system on the scale of some past eruptions.

‘Sooner or later we will experience a large volcanic eruption, and perhaps a cluster of them, that will act to exacerbate drought in sensitive parts of the world.’

 

Read more at DailyMail.co.uk