{"id":80771,"date":"2016-05-31T11:03:43","date_gmt":"2016-05-31T11:03:43","guid":{"rendered":"http:\/\/globalpress.hinduismnow.org?p=5604&preview_id=5604"},"modified":"2016-05-31T11:03:43","modified_gmt":"2016-05-31T11:03:43","slug":"did-climate-change-kill-the-indus-civilisation","status":"publish","type":"post","link":"https:\/\/globalpress-new.hinduismnow.org\/?p=80771","title":{"rendered":"Did Climate Change Kill The Indus Civilisation? – Swarajya"},"content":{"rendered":"
\n
\n

The Times of India<\/i> tells us<\/a>
\nthat it\u2019s time to rewrite the history books. New evidence has surfaced which
\nclaims that the Indus Valley Civilisation is much older than we initially thought.
\nEven older than the Egyptian and Mesopotamian ones. More than 8,000 years old.<\/p>\n

The Times of India should be
\ncomplimented for spotting this valuable research story, published in Scientific Reports, a journal published by Nature publications. Perhaps, it was the first newspaper to cover the story.<\/p>\n

However, the story has some false claims.<\/p>\n

First, its not \u2018new evidence\u2019. It\u2019s an old study. The authors of the paper themselves have cited Rao, L. S., Sahu, N. B., Sahu, P., Shastry, U. A. & Diwan, S. New light on the excavation of Harappan settlement at Bhirrana. Puratattva 35, 67\u201375 (2005)<\/i>. 2005, that\u2019s 11 years old news.<\/p>\n

In fact, their central idea in the paper is about the possibility of a connect between climate, agriculture and subsistence pattern during the Harappan civilization.<\/p>\n

Also, the claim that scientists have said climate change killed the Indus civilisation is plain wrong. This is not the impression one gets when reading the original research paper. Things are more complicated than that. The authors of the research paper say this in the abstract itself:<\/p>\n<\/div>\n

\n
\n

Our study suggests that other cause like change in subsistence strategy by shifting crop patterns<\/b> rather than climate change was responsible<\/b> for Harappan collapse.<\/p>\n

 <\/p>\n<\/div>\n<\/div>\n

\n

The research paper, published on 25 May is
\nattributed to Anindya Sarkar, Arati Deshpande
\nMukherjee, M. K. Bera, B. Das, Navin Juyal, P. Morthekai, R. D. Deshpande, V. S. Shinde, L. S. Rao.<\/p>\n

Anyway, we will come to the topic of \u201cwhat caused the
\ndownfall of Indus civilisation\u201d (according to the authors) later. First, let\u2019s
\ndiscuss the finding that\u2019s going viral, courtesy Times of India\u2019s <\/i>catchy headline.<\/p>\n

Establishing the antiquity
\nof Harappa Civilisation<\/b><\/p>\n

Based on radiocarbon dating obtained from more than hundred
\nHarappan and nearby sites, Harappan cultural levels have been classified into
\nfour phases:<\/p>\n

– Early Ravi Phase (~5700 years\u20134800 years Before Present [BP])<\/p>\n

– Transitional Kot Diji phase (~4800 years\u20134600 years BP)<\/p>\n

– Mature phase (~4600
\nyears\u20133900 years BP)<\/p>\n

– and Late declining phase (3900 years\u20133300 years BP).<\/p>\n

The Indus civilisation evolved from one being representative of
\npastoral and arable farming to a highly urbanised one which boasted of rich art
\nand culture, a functioning currency system and vibrant trade relations with
\nregions as far as Mesopotamia and Arabia. This prosperous phased was then
\nfollowed by de-urbanisation and decline.<\/p>\n

One of the leading experts on Indus Valley, late Gregory
\nPossehl, challenged this conventional chronology and advocated a much older chronology.
\nBased on the spatio-temporal distribution of the archaeological remains spread
\nthroughout the subcontinent, the paper says, the time spans of the above four
\nphases were revised (not by them, Times Of India<\/i>) to ~9000\u20136300\u2009years BP, 6300\u20135200 years
\nBP, 5200\u20133000 years BP and 3000\u20132500 years BP respectively. Here is the carbon
\ndating evidence that supports this classification.<\/p>\n<\/div>\n

\n
\n

A large number (~70) of conventional and AMS radiocarbon dates indeed support the antiquity of this phase in different parts of the Indus-Ghaggar Hakra river belts viz. Girawad (Pit-23, 6200 years BP), Mithathal (Trench A-1, 8200 years BP), Kalibangan (sample TF-439, 7600 years BP). The recent excavations at Rakhigarhi suggest hitherto unknown largest Harappan settlement in India preserving all the cultural levels including the Hakra phase (sample S-4173, 6400 years BP.<\/p>\n

 <\/p>\n<\/div>\n<\/div>\n

\n

The carbon dating of
\ncharcoal samples and that of pottery using a technique called Optically
\nStimulated Luminescence (OSL) reveals:<\/p>\n

\u201cAt Bhirrana the earliest
\nlevel has provided mean 14C age of
\n8350\u2009\u00b1\u2009140\u2009years BP (8597 to 8171 years BP). The successive cultural levels at
\nBhirrana, as deciphered from archeological artefacts along with these 14C ages,
\nare Pre-Harappan Hakra phase (~9500\u20138000 years BP), Early Harappan (~8000\u20136500\u2009years
\nBP), Early mature Harappan (~6500\u20135000 years BP) and mature Harappan (~5000\u20132800\u2009years
\nBP.)\u201d<\/p>\n

Bhirrana is a small
\nvillage in the Fatehabad district of Haryana. Located near the Ghaggar-Hakra river basin, this Harappan site is currently the oldest site of the civilisation and
\nhas retained all the cultural levels.<\/p>\n

How did the scientists confirm the antiquity of the Bhiranna
\nsettlement?<\/b><\/p>\n

To check the validity<\/b> of
\nradiocarbon dates (which already establish that Bhirrana is an 8,000+ years old site) and the antiquity of the settlement, the team of scientists
\nisotopically analysed teeth and bone phosphates excavated from one of the
\ntrenches of the settlement. They dated pottery fragments from mature and early
\nmature phases by the OSL method. This is what they found:<\/p>\n<\/div>\n

\n
\n

The pottery at 42\u2009cm, identified as mature Harappan level yielded mean 4800\u2009\u00b1\u2009300 (1\u03c3) years BP age (range 5120 to 4520 year BP) while the pottery from deeper level corresponding to early mature Harappan at 143\u2009cm yielded 5900\u2009\u00b1\u2009250 (1\u03c3) years BP age (range 6185 to 5695 year BP).<\/p>\n

 <\/p>\n<\/div>\n<\/div>\n

\n

In the Hakra level
\n(pre-harappan), at 300cm and more depth, the age is found to be 8384 years BP.<\/p>\n

\u201cIsotope based
\npaleoclimatic information also lends supports to the antiquity of Harappan
\nsettlements at Bhirrana,\u201d the scientists claim.<\/p>\n

(For complete methodology
\nand the explanation of the processes, please read the original research paper<\/a>.)<\/p>\n

Did Climate Change lead to the \u201ccollapse\u201d of civilisation?<\/b><\/p>\n

First, scientists
\ndon\u2019t agree with the assumption that the Indus civilisation suddenly collapsed. The
\nevidence doesn\u2019t support this hypothesis, they say. Why exactly?<\/p>\n

\u201cAlthough the collapse of
\nthe Harappan as well as several contemporary civilisations like Akkadian
\n(Mesopotamia), Minoan (Crete), Yangtze (China) has been attributed to either
\nweakening of monsoon or pan-Asian aridification (drought events) at ~4100 years
\nBP, the evidence is both contradictory and incomplete. Either the climatic
\nevents and cultural levels are asynchronous or
\nthe climate change events themselves are regionally diachronous,\u201d they reason.<\/p>\n

There is no continuous
\nclimate record for the particular sites of the civilisation. Plus, the
\nclimate reconstructions made for sites like Thar desert or Arabian sea to show
\na relation between the collapse of Harappa and weakening monsoon cannot give a
\ntrue representation since these sites are far from the Harappan ones. Climate
\nin those areas could have been influenced by other factors than what might have
\naffected Harappan sites.<\/p>\n

With the help of isotope
\nbase paleoclimatic information, scientists found that the weak monsoon
\nphase existed before 9000 years BP too, Not just in India but throughout Asia.
\nIt only intensified from 9000 years BP to 7000 years BP. This intensified
\nmonsoon period transformed the Ghaggar-Hakra into mighty rivers. And
\nsettlements on their banks became the cradle of civilisation. As the low monsoon
\nphase returned from mature Harappan period onwards, these rivers lost their
\nmojo.<\/p>\n

Using a simple moisture
\nflux method, the scientists have estimated that the monsoon precipitation
\nduring the intensified monsoon period (9000-7000 years BP) was ~100-150 mm
\nhigher than today. During the weak monsoon phase (7000 years BP to mature
\nHarappan phase), the mean annual rainfall was similar to present day
\nnon-monsoon months. According to another paper<\/a> published in 2014, this drought phase existed for over 200 years (100 years give and take).<\/p>\n

This converted the
\nperennial rivers into dry ones. It definitely hurt the civilisation. But it
\ndidn\u2019t collapse. People evolved. Settlements survived at most of the sites,
\nincluding Bhirrana. The Indus civilisation continued to thrive despite weak monsoon
\nphase. So, climate change cannot alone be attributed to the fall of
\ncivilisation. Scientists say:<\/p>\n<\/div>\n

\n
\n

It is difficult to point to one single cause that drove the Harappan decline<\/b>.\u2026\u2026..The continued survival of Harappans at Bhirrana suggests adaptation to at least one detrimental factor that is monsoon change.<\/p>\n

 <\/p>\n<\/div>\n<\/div>\n

\n

Archeobotanical data
\nsuggests that people changed the crop pattern and subsistence strategy. Crop
\npatterns in and around Bhirrana indicate that people shifted from the
\nlarge-grained cereals like wheat and barley to drought-resistant species of
\nsmall millets and rice. People moved from large storage system (one of the
\nfeatures of Harappan sites) to an individual household one.<\/p>\n

This, scientists believe
\nacted as catalyst for the de-urbanisation and later decline of the Harappan
\ncivilization. There was no sudden collapse. And multiple factors (agriculture,
\nchange in crop pattern etc) other than climate change did the civilisation in.<\/p>\n

But we shouldn\u2019t ignore the fact that the 200-year drought started this chain of events which culminated in the end of the civilisation. These new findings have
\nmajor lessons for us. We are still overdependent on monsoon for our
\nagriculture. As far as our water management is concerned, less said the better.<\/p>\n

Even today, two years of weak monsoons impact the country so adversely.<\/p>\n<\/div>\n<\/div>\n

 <\/p>\n

Source: Did Climate Change Kill The Indus Civilisation? \u2013 Swarajya<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

The Times of India tells us that it\u2019s time to rewrite the history books. New evidence has surfaced which claims that the Indus Valley Civilisation is much older than we initially thought. Even older than the Egyptian and Mesopotamian ones. More than 8,000 years old. The Times of India should be complimented for spotting this […]<\/p>\n","protected":false},"author":19,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":""},"categories":[1133],"tags":[],"_links":{"self":[{"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=\/wp\/v2\/posts\/80771"}],"collection":[{"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=80771"}],"version-history":[{"count":0,"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=\/wp\/v2\/posts\/80771\/revisions"}],"wp:attachment":[{"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=80771"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=80771"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/globalpress-new.hinduismnow.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=80771"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}