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  • 2019-04-02 (xsd:date)
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  • Viral meme about Al Gore and glaciers is wrong (en)
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  • Former vice president Al Gore has used his celebrity to try to curb the worst consequences of climate change. The 2006 movie An Inconvenient Truth, for example, follows Gore as he discusses the dangers of global warming. A recent Facebook post seems to play on that film title with a claim about glaciers. The day Al Gore was born, there were 130,000 glaciers on earth, reads the text of a Facebook post featuring pictures of the veep. Today, only 130,000 remain. Awkward, wrote the Facebook account that published the post on March 11. It was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook .) We turned to research and climate scientists to help us figure out if it’s accurate. What’s a glacier? A glacier is a body of snow and ice that’s big enough in size and mass to move under its own weight, according to the U.S. Geological Survey . But what qualifies as a glacier depends on who you ask. The USGS defines them according to the commonly accepted guidelines in which a body of ice has an area of at least 0.1 kilometers squared, or about 25 acres. But that’s not universal. Over in Argentina, for example, a grassroots group challenged the size cutoff for a glacier to be included in the country’s national inventory, arguing it has imperiled important water sources. And a recent study in the journal Nature discusses sea level rise from uncharted glaciers, ones that disappeared before they were documented or are missing, meaning they’re too small to be included in inventories. William Colgan, a senior researcher with the Geological Survey of Denmark and Greenland, told PolitiFact that the emerging global standard for defining a glacier is a minimum of 1 hectare, or 100 meters by 100 meters. How many glaciers were there in 1948? According to Colgan, we don’t know what the global number of glaciers was in 1948, the year Al Gore was born . Scientists use satellites to map glaciers and reliable satellite monitoring didn’t start until the mid 1980s. We just don’t have the snapshots from space in 1948, Colgan said. How many glaciers are there today? We do have estimates of the total number of glaciers today. According to the Randolph Glacier Inventory , Colgan said, there are 197,654 glaciers that are at least 1 hectare, or 0.01 square kilometers. That’s 67,654 more than the Facebook post says, not counting the thousands of missing glaciers, Colgan said. Walt Meier, a research scientist with the National Snow and Ice Data Center, told PolitiFact that inventories are always changing. The numbers could increase because more glaciers are getting mapped, he said. One database on the center’s website lists 306,865 glaciers, for example. Michael Kemp, director of the World Glacier Monitoring Service, cited 215,000 glaciers today. He said in an email that the number 130,000 probably comes from the World Glacier Inventory, which is a snapshot of the glacier distribution in the second half of the 20th century. But, Kemp said, it’s not globally complete. How have glaciers changed over the decades? Kemp said that though it’s clear glaciers have been shrinking worldwide since the mid 19th century, the number of glaciers may not have changed much. That’s because while some glaciers have vanished altogether, others have disintegrated from one large glacier complex into smaller tributary glaciers. Jim White, a climate scientist and interim dean of the College of Arts and Sciences at the University of Colorado Boulder, said a better measure of glacier change is ice volume, because that translates to potential sea level rise if that ice melts. Satellites give us area, not volume, so numbers of glaciers is interesting but volume change is more important for Miami, he said. (The coastal city is vulnerable to sea level rise .) How much ice have we lost since Al Gore was born? Citing a 2017 Arctic Monitoring and Assessment Programme study Colgan worked on, he said the world has lost about 33,000 gigatons of ice since 1948. To put a gigaton in perspective, scientists estimate we’re losing 159 gigatons of ice from Antarctica each year, according to the Washington Post . That’s about a third of all the water in Lake Erie. The changes are so great with land ice, it’s like the poster child of climate change, Colgan said. Everywhere you look, you see massive change. Consider Glacier National Park, in Montana. In an undated post about the park, the U.S. Geological Survey says there were an estimated approximate 150 glaciers in 1850. Most of those glaciers were still there when the park was established in 1910. But by 2015, there were 26 remaining glaciers larger than 25 acres. Glaciers are dynamic. They respond to temperature and precipitation. But they retreat when melting outpaces the accumulation of new snow. And, USGS notes, worldwide glacial glacier recession is well documented. Early park visitors and scientists noted that glaciers were retreating as early as 1914, according to the post. The climate was already warming and glaciers were responding, but the industrial revolution added more carbon dioxide to the atmosphere, furthering glacier retreat. All glaciers have reduced in size in the park since 1966, according to USGS, and some had retreated as much 85 percent by 2015. (You can see photos showing how the Shepard Glacier in the park has changed from 1913 to 2005.) Our ruling The Facebook post claims that there were 130,000 glaciers in 1948 and there are 130,000 glaciers today. We don’t know how many glaciers there were in 1948, and there are actually tens of thousands more glaciers worldwide today than the post says. But context matters here, and the post suggests that glaciers haven’t changed in the 70 years since Al Gore was born. That’s also incorrect. As Walt Meier, the research scientist with the National Snow and Ice Data Center, told us, the number of glaciers isn’t really relevant in terms of assessing climate change. What matters, he said, is the change in mass. Are glaciers as a whole gaining or losing ice? he asked. On that question, the answer is very clear — glaciers are losing mass. We rate this post as False. Share the Facts 2019-04-02 14:52:29 UTC PolitiFact 2 1 7 PolitiFact Rating: False The day Al Gore was born, there were 130,000 glaciers on earth. Today, only 130,000 remain. Viral image On the internet Monday, March 11, 2019 2019-03-11 Read More info (en)
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