Sarah Palin says man isn’t to blame for climate change, citing the fact that some glaciers in Alaska are expanding. But an individual glacier’s growth does not disprove the existence or causes of global warming. In fact, the vast majority of glaciers in Alaska and around the world are losing ice rapidly. Palin, the former Alaska governor and 2008 presidential nominee, appeared on CNN’s “State of the Union” (at the 2:25 mark). Host Jake Tapper asked if she takes climate change seriously.
Palin responded: “I take changes in the weather, the cyclical changes that the globe has undergone for – since the beginning of time, I take it seriously, but I’m not going to blame these changes in the weather on man’s footprint. Obama was up there looking at, say, the glaciers and pointing out a glacier that was receding. Well, there are other glaciers, though, that are growing up here. And he didn’t highlight that, but he used glaciers as an example.”
Palin may not blame climate change on humans, but science does; various media have covered before how scientists say it’s extremely likely that most of the observed temperature rise has been caused by human emissions. Her claim that some glaciers are growing in Alaska is true, but this isn’t a reason to question human-caused climate change. Regional variations in precipitation patterns may cause some glaciers to grow, but most glaciers around the world are losing ice as the climate warms.
But Palin pointed out that not all glaciers are losing ice. In a post on the opinion website IJ Review, she highlighted the Hubbard Glacier in Alaska. According to NASA, the Hubbard has indeed been advancing since measurement of the glacier began in 1895, at rates ranging from 13 meters to 36 meters per year.
Leigh Sterns, a glaciologist at the University of Kansas, explained this glacier’s growth for NASA: “Hubbard’s advance is due to its large accumulation area; the glacier’s catchment basin extends far into the Saint Elias Mountains. Snow that falls in the basin either melts or flows down to the terminus, causing Hubbard to steadily grow.” However, according to the most recent WGMS data, only 22 of the 126 glaciers it analyzed were adding mass, while 104 – about 83 percent – were losing mass.
In spite of that trend, a minority of glaciers, such as the Hubbard, will likely continue to expand even with warmer temperatures. For example, a study published in 2014 in Nature Geoscience described the stable of growing glaciers of the Karakorum region in Asia. The reason for those glaciers’ deviation from the global trend has to do with localized changes to winter precipitation – snowfall, essentially, helps the glaciers stay stable or grow. The authors concluded that “[o]ur findings suggest a meteorological mechanism for regional differences in the glacier response to climate warming.” In other words, local weather patterns play a role in how glaciers respond to climate change.