Glacial lakes have grown 48% in the last 30 years due to melting glaciers

Hyperaxion Sep 3, 2020

After studying lakes on almost every continent, scientists saw that increasing water volume affects communities and ecosystems that exist nearby.

In the largest-ever study on glacial lakes, researchers from Canadian, American, and British institutions found that the volume of these aquatic ecosystems has increased 48% since 1990, as glaciers melt due to climate change.

Glacial lakes have grown 48% in the last 30 years due to melting glaciers
Lake Imja, near Mount Everest in the Himalaya, is a glacial lake that has tripled in size since 1990. (Credit: Planetary Science Institute / Jeffrey S. Kargel).

In an article published earlier this week in the journal Nature Climate Change, scientists say they have used data collected by NASA over the past 30 years.

The study estimates that the current volume of combined glacial lakes reaches 156 cubic kilometers (37.4 cubic miles) of water, equivalent to one-third of the volume of Lake Erie, between the United States and Canada, which is one of the largest on the planet.

“We have known that not all meltwater is making it into the oceans immediately,” said Dan Shugar, lead author of the study. “But until now there were no data to estimate how much was being stored in lakes or groundwater.”

The scientists began the study by researching some glacial lakes in the Asian mountains, a geographical region that includes the Tibetan Plateau and surrounding mountain ranges, including the Himalaya.

After the success of the analyzes, they decided to make the observations more comprehensive, creating a worldwide estimate, except for Antarctica.

The team analyzed more than 250,000 records made by NASA’s Landsat satellite mission. According to the researchers, a decade ago it would not be possible to process and analyze this volume of data, but with current technology, it was.

“We wrote scripts in Google Earth Engine, an online platform for very large analyses of geospatial data, to look only at High Mountain Asia, and then decided to look at all glacial lakes in the world,” Shugar said.

“From there, we were able to build a scaling relationship to estimate the volume of the world’s glacial lakes based on the area of this large population of lakes.”

Although water from melting glaciers stored in glacial lakes contributes little to the overall rise in sea level, it can have a major impact on the communities and ecosystems that exist nearby, in places like the Andes, Bhutan, and Nepal, for example, where floods can be devastating.

“Fortunately, organizations like the United Nations are facilitating a lot of monitoring and some mitigation work where they’re lowering the lakes to try and decrease the risks,” Shugar explained.

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