News / Science & Technology

    Study: Climate Change Sped Indus Empire's Collapse

    A city-settlement of the the Indus Valley Civilization, ca. 2600-1500 BCE. (Comrogues, Creative Commons)
    A city-settlement of the the Indus Valley Civilization, ca. 2600-1500 BCE. (Comrogues, Creative Commons)
    Rosanne Skirble
    Climate change may have hastened the end of the largest civilization in the ancient world, according to a study in the Proceedings of the National Academy of Sciences.

    The Indus empire, larger than its contemporaries Egypt and Mesopotamia combined, once held 10 percent of the world’s population and spanned 1 million square kilometers across the plains of the Indus River, from the Arabian Sea to the Ganges, encompassing what is today Pakistan, eastern Afghanistan and northwest India.

    Despite its great cities and trade routes, the Indus civilization disappeared some 3,000 years ago and was nearly forgotten until the 20th Century, when archaeologists began unearthing its lost treasures. 

    Trenches reveal signs of how the landscape was shaped by rivers, wind and climate. (Peter D. Clift/University of Aberdeen)Trenches reveal signs of how the landscape was shaped by rivers, wind and climate. (Peter D. Clift/University of Aberdeen)
    x
    Trenches reveal signs of how the landscape was shaped by rivers, wind and climate. (Peter D. Clift/University of Aberdeen)
    Trenches reveal signs of how the landscape was shaped by rivers, wind and climate. (Peter D. Clift/University of Aberdeen)
    Unlike the Egyptians or the Mesopotamians, the Indus didn’t build large temples or pyramids. Lead author Liviu Giosan, a geologist at the Woods Hole Oceanographic Institution, says the Indus people were more interested in agriculture and trade

    “They farmed all the Indus Basin," Giosan says. "They had an extremely developed network of roads. They had sea links with Mesopotamia. They built big cities, orderly cities, in a grid. They had plumbing that was never encountered after that until the Romans came.”  

    Archeological ruins of the Indus people, also known as the Harappans, were discovered in the 1920s. Studies since then have described an urban culture with sophisticated construction, sanitation systems, arts and crafts, and writing still not deciphered.  

    In their work, Giosan and his colleagues used satellite images and topographical data to construct a model of the landscape where the Indus developed 5,200 years ago, built their cities, and then slowly declined between 3,900 and 3,000 years ago. 

    “We went and dug trenches, or took sediment cores, or drilled to collect samples of sediment, so that we could understand where they formed," Giosan says. "Were they formed by the river? Were they formed by the wind, and when [were] they formed?”

    The digital maps from the satellite images and the sediment records taken together reveal how agriculture and settlement patterns changed as the climate changed. 

    Researchers collect sample sediment cores to chronicle changes in the Indus landscape over time. (Peter D. Clift/University of Aberdeen)Researchers collect sample sediment cores to chronicle changes in the Indus landscape over time. (Peter D. Clift/University of Aberdeen)
    x
    Researchers collect sample sediment cores to chronicle changes in the Indus landscape over time. (Peter D. Clift/University of Aberdeen)
    Researchers collect sample sediment cores to chronicle changes in the Indus landscape over time. (Peter D. Clift/University of Aberdeen)
    Among the most striking features, which the authors describe for the first time, is a mounded plain of river sediment, 10-to-20 meters high, 100 kilometers wide and running almost 1,000 kilometers along the Indus River. Giosan says it is seen as a sign of stability of the landscape.

    According to the research, monsoon rains allowed settlements to grow and farming and trade to prosper. But when the monsoons began to bring less rain, the Indus did not irrigate their crops. Instead, they migrated eastward settling in smaller communities supported by rain-fed farming and dwindling streams for 1,000 years before their culture died out.  

    The Indus River today is the source of the largest irrigation system in the world. But that system depends on a stable climate. Giosan says today’s changing climate - and the potential for more intense floods, like those that inundated Pakistan in 2010, could put millions of lives at risk.

    “Then we have a problem. The entire Indus system, with its dams and canals for irrigation, is obsolete. It cannot function in that kind of climate. It is kind of a reversal to earlier types of climates when the river was wild. And we have to rethink that kind of development in the region.”

    Giosan notes that people living there today cannot move across borders as easily as the Indus did so long ago, when the monsoons began to weaken. Giosan says the study provides a lesson from the past: that today’s mighty civilizations - whose industrial activities have sped the pace of climate change - must act to slow it or face the consequences.

    You May Like

    Video Rubio Looks to Surge in New Hampshire

    Republican presidential candidate has moved into second place in several recent surveys and appears to be gaining ground on longtime frontrunner Donald Trump

    UN Calls for Global Ban on Female Genital Mutilation

    Recent UNICEF report finds at least 200 million girls and women alive today have undergone female genital mutilation in 30 countries

    UN Pilots New Peace Approach in CAR

    Approach launched in northern town of Kaga Bandoro, where former combatants of mainly Muslim Seleka armed group and Christian and animist anti-Balaka movement are being paid to do community work

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    German Artists to Memorialize Refugees With Life Jacket Exhibiti
    X
    Hamada Elsaram
    February 05, 2016 4:30 PM
    Sold in every kind of shop in some Turkish port towns, life jackets have become a symbol of the refugee crisis that brought a million people to Europe in 2015.  On the shores of Lesbos, Greece, German artists collect discarded life jackets as they prepare an art installation they plan to display in Germany.  For VOA, Hamada Elrasam has this report from Lesbos, Greece.
    Video

    Video German Artists to Memorialize Refugees With Life Jacket Exhibit

    Sold in every kind of shop in some Turkish port towns, life jackets have become a symbol of the refugee crisis that brought a million people to Europe in 2015.  On the shores of Lesbos, Greece, German artists collect discarded life jackets as they prepare an art installation they plan to display in Germany.  For VOA, Hamada Elrasam has this report from Lesbos, Greece.
    Video

    Video E-readers Help Ease Africa's Book Shortage

    Millions of people in Africa can't read, and there's a chronic shortage of books. A non-profit organization called Worldreader is trying to help change all that one e-reader at a time. VOA’s Deborah Block tells us about a girls' school in Nairobi, Kenya where Worldreader is making a difference.
    Video

    Video Genius Lets World Share Its Knowledge

    Inspired by crowdsourcing companies like Wikipedia, Genius allows anyone to edit anything on the web, using its web annotation tool
    Video

    Video Former Drug CEO Martin Shkreli Angers US Lawmakers

    A former U.S. pharmaceutical business executive has angered lawmakers by refusing to explain why he raised the price of a life-saving pill by 5,000 percent. Martin Shkreli was removed from a congressional hearing on Thursday after citing his Fifth Amendment right to stay silent. Zlatica Hoke has more.
    Video

    Video Super Bowl TV Commercials are Super Business for Advertisers

    The Super Bowl, the championship clash between the two top teams in American Football, is the most-watched sporting event of the year, and advertisers are lining up and paying big bucks to get their commercials on the air. In fact, the TV commercials during the Super Bowl have become one of the most anticipated and popular features of the event. VOA's Brian Allen has a sneak peek of what you can expect to see when the big game goes to commercial break, and the real entertainment begins.
    Video

    Video In Philippines, Mixed Feelings About Greater US Military Presence

    In the Philippines, some who will be directly affected by a recent Supreme Court decision clearing the way for more United States troop visits are having mixed reactions.  The increased rotations come at a time when the Philippines is trying to build up its military in the face of growing maritime assertiveness from China.  From Bahile, Palawan on the coast of the South China Sea, Simone Orendain has this story.
    Video

    Video Microcephaly's Connection to Zika: Guilty Until Proven Innocent

    The Zika virus rarely causes problems for the people who get it, but it seems to be having a devastating impact on babies whose mothers are infected with Zika. VOA's Carol Pearson has more.
    Video

    Video Solar Innovation Provides Cheap, Clean Energy to Kenya Residents

    In Kenya, a company called M-Kopa Solar is providing clean energy to more than 300,000 homes across East Africa by allowing customers to "pay-as-you-go" via their cell phones. As Lenny Ruvaga reports from Kangemi, customers pay a small deposit for a solar unit and then pay less than a dollar a day to get clean energy to light up their homes or businesses.
    Video

    Video Stunning Artworks Attract Record Crowds, Thanks to Social Media

    A new exhibit at the oldest art museum in America is shattering attendance records. Thousands of visitors are lining up to see nine giant works of art that have gotten a much-deserved shot of viral marketing. The 150-year-old Smithsonian American Art Museum has never had a response quite like this. VOA's Julie Taboh reports.
    Video

    Video Apprenticeships Put Americans on Path Back to Work

    Trying to get more people into the U.S. workforce, the Obama administration last year announced $175 million in grants towards apprenticeship programs. VOA White House correspondent Aru Pande went inside one training center outside of Washington that has gained national recognition for helping put people on the path to employment.
    Video

    Video New Material May Reduce Concussion Effects

    As the 2016 National Football League season reaches its summit at the Super Bowl this coming Sunday (2/7), scientists are trying to learn how to more effectively protect football players from dangerous and damaging concussions. Researchers at Cardiff and Cambridge Universities say their origami-based material may solve the problem. VOA’s George Putic reports.
    Video

    Video Saudi Arabian Women's Sports Chip Away at Stereotypes

    Saudi Arabian female athletes say that sports are on the front line of busting traditions that quash women’s voices, both locally and internationally. In their hometown of Jeddah, a group of basketball players say that by connecting sports to health issues, they are encouraging women and girls to get out of their homes and participate in public life. VOA’s Heather Murdock reports.
    Video

    Video A Year Later, Fortunes Mixed for Syrians Forging New Lives in Berlin

    In April of last year, VOA followed the progress of six young Syrian refugees -- four brothers and their two friends -- as they made their way from Libya to Italy by boat, and eventually to Germany. Reporter Henry Ridgwell caught up with the refugees again in Berlin, as they struggle to forge new lives amid the turmoil of Europe's refugee crisis.
    Video

    Video Zika Virus May be Hard to Stop

    With the Zika virus spreading rapidly, the World Health Organization Monday declared Zika a global health emergency. As Alberto Pimienta reports, for many governments and experts, the worst is yet to come.