The first modern case of “river piracy” has been observed by scientists, where most of the water running from a large glacier in north-west Canada last year, suddenly switched from one river to another. Normally, the process takes several thousand years for a river to expire as tectonic forces, natural damning or erosion cause the water to re-route into a different path. Scientists blame this phenomenon on global warming.
Slims River was a three-metre deep raging river and had become much more shallow after the changes. Currently, the melt-water from the Yukon’s Kaskawulsh glacier flows majorly into the Alsek River, ending up in the Pacific Ocean instead of the Arctic’s Bering Sea. The redistribution has already negatively impacted both the regions’ ecosystems, causing disruptions to lake chemistry, fish populations and the behavior of wildlife.
Case Analysis by Scientists
According to Dan Shugar, a professor at the University of Washington Tacoma who studies land changes, it seemed to “all happen in about one day – last May 26”, where a 30-metre tall canyon formed at the end of the glacier re-routing the melting water. This study was published in a journal called Nature Geoscience by Shugar and his colleagues.
“River piracy” is commonly used to describe events that occur over a long time, such as thousands of years, and had not been witnessed in modern times, especially not this quickly, as per Jim Best of the University of Illinois, the study’s co-author. The Kaskawulsh glacier covers approximately 25,000 square kilometres. Shugar stated, that the front of the glacier has retreated about 1.9 kilometres since 1899.
The scientists had visited the edge of Kaskawulsh glacier in 2013. At that time, the Slims River was “swift, cold and deep”, flowing fast enough to be considered dangerous to wade through, Shugar stated. The scientists further returned to the same point last year in 2016, to eventually discover that the Slims River had become shallow and still as a lake, while the Alsek River had become deeper with a faster flow.
“What had been a river delta at the edge of the Slims River had changed into a place full of “afternoon dust storms with this fine dust getting into your nose and your mouth”.
Shugar also explained that the water reduction in the Slims River cannot be attributed to the changes in rainfall. This is because the Slims River is mainly fed by glacial melt, not rain.
The journal Nature Geoscience, published a statistical analysis, suggesting that the dramatic changes can almost certainly be attributed to anthropogenic climate change. To arrive at this conclusion, they used weather and ice observations along with a computer simulation to model the likelihood of the glacier retreat with the current conditions, excluding the heat-trapping greenhouse gases. Hence, the scientists have calculated that there is only 1 in 200 chance that the retreating glacier and river privacy is entirely natural without man-made global warming. Best claimed that the chance of piracy having occurred due to warming over the industrial area is 99.5%.
Consequences: Current and Future
Various other scientists have acknowledged and appreciated the study as significant and sensible. Richard Alley, a glacier expert at the Pennsylvania State University (not part of the study), said, “This is an interesting study and reconfirms that climate change has large, widespread and sometimes surprising impacts”.
The Logical Indian urges everyone to consider the long-term consequences of global warming contributed by humans. We encourage individuals to make their contributions towards an environmentally friendly lifestyle in order to support a better future.