In the largest-ever study of glacial lakes, researchers using 30 years of NASA satellite data have found that the volume of these lakes worldwide has increased by about 50% since 1990 as glaciers melt and retreat due to climate change.
The findings, published in the journal Nature Climate Change, will aid researchers assessing the potential hazards to communities downstream of these often unstable lakes and help improve the accuracy of sea level rise estimates by advancing our understanding of how glacial meltwater is transported to the oceans.
Glaciers are retreating on a near-global scale and this study provides scientists with a clearer picture of how much of this water has been stored in lakes.
“We have known that not all meltwater is making it into the oceans immediately,” said lead author Dan Shugar of the University of Calgary in Canada. “But until now there were no data to estimate how much was being stored in lakes or groundwater.” The study estimates current glacial lake volumes total about 37.4 cubic miles (156 cubic kilometers) of water, the equivalent of about one-third the volume of Lake Erie.
In the largest-ever study of glacial lakes, researchers using a 30-year satellite data record have found that the volume of these lakes worldwide has increased by about 50% since 1990. Credit: NASA
Shugar and his collaborators from governments and universities in Canada, the United States, and the United Kingdom, working under a grant from NASA’s High Mountain Asia Program, initially planned to use satellite imaging and other remote-sensing data to study two dozen glacial lakes in High Mountain Asia, the geographic region that includes the Tibetan Plateau and surrounding mountain ranges, including the Himalaya.
“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.”
The team ultimately analyzed more than 250,000 scenes from the Landsat satellite missions, a joint NASA/U.S. Geological Survey program. A decade ago it would not have been possible to process and analyze this volume of data. The team looked at the data in five time-steps beginning with 1990 to examine all the glaciated regions of the world except Antarctica and analyze how glacial lakes changed over that period.
Shugar points out that while water from melting glaciers stored in glacial lakes is a relatively small contributor to overall sea level rise, it can have a major impact on mountain communities downstream of these glacial lakes.
Glacial lakes are not stable like the lakes in which most people are used to swimming or boating because they are often dammed by ice or glacial sediment called a moraine, which is composed of loose rock and debris that is pushed to the front and sides of glaciers. Rather, they can be quite unstable and can burst their banks or dams, causing massive floods downstream. These kinds of floods from glacial lakes, known as glacial lake outburst floods, have been responsible for thousands of deaths over the past century, as well as the destruction of villages, infrastructure, and livestock. A glacial lake outburst flood affected the Hunza Valley in Pakistan in May 2020.
“This is an issue for many parts of the world where people live downstream from these hazardous lakes, mostly in the Andes and in places like Bhutan and Nepal, where these floods can be devastating,” Shugar said. “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.”
In North America, the risks posed by a glacial lake outburst flood are lower.
“We don’t have much in the way of infrastructure or communities that are downstream,” Shugar said. “But we’re not immune to it.”
Reference: “Rapid worldwide growth of glacial lakes since 1990” by Dan H. Shugar, Aaron Burr, Umesh K. Haritashya, Jeffrey S. Kargel, C. Scott Watson, Maureen C. Kennedy, Alexandre R. Bevington, Richard A. Betts, Stephan Harrison and Katherine Strattman, 31 August 2020, Nature Climate Change.
FLASH: The world’s glaciers started melting almost 12,000 years ago. News at eleven!
Wake up to reality folks! Your planet is dying before your eyes! The world’s climate conditions are under attack from us humans polluting lifestyles and in about 15-30 years our world’s atmosphere will drastically change from how it is now and how it was for the last millions of years. As much as there are major changes happening today to our world’s climates what we will face in the future will scare the hell out of all of you no matter what political party you are and no matter what you may or may not believe about global warming! The weakest part of the ice system on Earth is permafrost. Hot weather easily melts permafrost. Since the 1960’s on the Russian side of the Arctic Ocean the permafrost in Russia was melting at a more unusual rapid pace. This daily melted permafrost water from Russia has since the 1960’s been draining from the lands of Russia into the Arctic Ocean where it then started to melt the ice in the North Pole. There are videos out there showing the yearly progress of the ice melting in the North Pole. In the videos you can see the draining permafrost water yearly melting the North Pole ice. Over the years this former permafrost now melted warmer water was circulating around the North Pole where it then melted much more ice. This warmer water then started circulating around the globe where it started melting the South Pole. As waves reached out into the atmosphere and took in another gulp of now hotter air in our global warming era the oceans water got warmer worldwide from the hotter air and melted permafrost and melted ice. I wish that our government and NASA would start paying more attention to this planet than other planets and figure out just what is happening here on Earth than waste our tax money and much needed scientific work on things that are going on in outer space because these glaciers melting is a sign of very bad things to come! Think about this, what happens when in about 10-20 years when all the Earth’s glaciers will have melted. ALL people, animals and plant life that rely on water from streams, rivers and lakes will soon have no more water! Our atmosphere will have less humidity which will mean less clouds which will mean less rain which will mean more areas of the world will be without water! As life around the world goes into chaos because there is enough water to plant food or food or water to feed people and animals the world’s order will come to an end! The Sun daily shines on our planet and heats up everything on Earth and as it does it causes water molecules on Earth to evaporate into the sky. That evaporated water molecule somehow can somehow bunch together with other evaporated water molecules where it can form clouds and hopefully rain. If the evaporated water molecules don’t form clouds or form clouds that don’t produce rain then those evaporated water molecules forever disappear! The Sun can and will will make all the water on Earth evaporate as Suns have done numerous times throughout the universe. So you folks better start doing something now to stop global warming because in about 10 t0 25 years the Earth’s environment will no longer be able to support life as we know it. This is a warning, is anybody listening? Does anybody care?
I see that you are an optimist. A couple of years ago, AOC said that we have only 12 years left. It is difficult to get excited when people make claims that seem preposterous!
This is nothing but propaganda and Scaremongering.
Not even the most extreme environmentalist scientists are saying anything close to this.
10 to 25 years and the Earth will no longer be able to support life?
CO² levels were estimated to be just above 5,000 ppm 440 million years ago, (late Ordovician) over 11 times what it is today, and life was all over the Earth, thriving. Similarly, temperatures were much higher than they are now. We might not even have reached the Medieval Warm period, but it was warmer during part of the Roman era.
Plants are greener than they were just a few decades ago. Plants are thriving on the extra CO². There is a reason why greenhouses are kept at 2 to 3 times the CO² of the atmosphere.
Every inch of land that may be lost due to increased oceans is replaced by an inch of land freed from ice. Ice melting on the oceans has no effect, only the ice on land. (Same way ice that melting in your drink doesn’t push it over the edge of a cup.)
And the idea that “evaporated” water won’t rain? Are you kidding me? The atmosphere is not infinite in its ability to hold moisture. No matter what the average temperature there will still be weather, and rain will fall.
And the biggest joke is the idea that evaporated water will leave the Earth. That would have happened already if it was going to happen. Mars didn’t lose its water due to evaporation, it lost its magnetosphere, allowing the solar winds to slowly blow away its atmosphere. Less atmosphere is less pressure resulting in a lower boiling point. (Watch the videos of water boiling at room temperature in a vacuum.) And that water becomes part of the atmosphere, and also blows away. Nothing we have to worry about.
It would be interesting to know what happened in the Arctic during the 10,800 BCE abrupt climate change. We know there were two ice sheets – smaller Cordilleran and bigger Laurentide on North America. The Laurentide perhaps 3 – 4 km thick at some places.
There was a paper published in Feb 2018 in The Journal of Geology about extraordinary biomass burning around 10,800 BCE. It is fascinating.
Quote from The Journal of Geology in Feb 2018 : “Around 10,800 BCE ∼9% of Earth’s terrestrial biomass, on ∼10 million km2 (area as big as the US), burned. The concentrations of soot, used to estimate the global amount of biomass burned, suggest that wildfires around 10,800 BCE consumed considerably more biomass than during the K-Pg extinction event.”
If interested the links are https://www.journals.uchicago.edu/doi/abs/10.1086/695703?journalCode=jg for part 1 and https://www.journals.uchicago.edu/doi/abs/10.1086/695704 for part 2.
How much CO2 must have been released when ∼9% of world terrestrial biomass on ∼10 million km2 burned around 10,800 BCE due to the comet impact? The wildfires on 70,000 km² in Australia this year are estimated to release about 900 million tons of CO2, which equals to double the country’s total yearly fossil fuel emissions.
Perhaps CO2 released by burning of ∼9% of Earth’s terrestrial biomass, on ∼10 million km2 might have contributed to melting of Cordilleran and Laurentide ice sheets? At present CO2 melts ice in Arctic, Greenlad, Antarctica so we can assume it should have been melting ice also around 10,800 BCE as well.