A hundred years of cars, planes, wars, and five billion more polluting people, and there's nothing to show for it. Old log books kept by Scott and Shackleton show that Antarctic sea ice hasn't changed much since 1912 reports Joanne Nova. 1
Experts have been concerned that ice at the South Pole had declined significantly since the 1950s, which they feared was driven by man-made climate change. But new analysis suggests that conditions are now virtually identical to when the Terra Nova and Endurance sailed to the continent in the early 1900s, indicating that declines are part of a natural cycle and not the result of global warming. 2
“The missions of Scott and Shackleton are remembered in history as heroic failures, yet the data collected by these and other explorers could profoundly change the way we view the ebb and flow of Antarctic sea ice,” said Dr. Jonathan Day, co-author of a recent study. 3
The research was based on the ice observations recorded in the logbooks from 11 voyages between 1897 and 1917, including three expeditions led by Captain Scott, two by Shackleton, as well as sea ice records from Belgian, German and French missions. A map showing current sea ice extent in Antarctica and the routes of expedition ships, reveals that the edge of the continent is largely the same today as it was 100 years ago.
We know that sea ice in the Antarctic has increased slightly over the past 30 years since satellite observations began. Scientists have been grappling to understand this trend in the context of global warming, but these new findings suggest it may not be anything new.
These findings demonstrate that the climate of Antarctica fluctuated significantly throughout the 20th century and indicates that sea ice in the Antarctic is much less sensitive to the effects of climate change that that of the Arctic which has experienced a dramatic decline during the 20th century.
Other confounding items:
Then there's the Pine Island Glacier which is nearly two-thirds the size of Texas. An international team led by British Antarctic Survey reported that the present day thinning and retreat of Pine Island Glacier, one of the largest and fastest shrinking glaciers of the West Antarctic ice sheet, is part of a climate trend that was already underway as early as the 1940s when CO2 was only around 310 ppm. 4
The Antarctic Peninsula has actually cooled in the past two decades. 5
References
Joanne Nova, “Antarctic sea ice strangely the same as 100 years ago when Ford Model T was around,” joannenova.com November 26, 2016
Sarah Knapton, “Scott and Shackleton logbooks prove Antarctic sea ice is not shrinking 100 years after the expeditions,” The Telegraph, November 24, 2016
Tom Edinburgh and Jonathan Day, “Estimating the extent of Antarctic summer sea ice during the heroic age of Antarctic exploration,” The Cryosphere, 10, 2721, 2016
Steve Milloy,, “Oops...West Antarctic ice sheet melting as far back as 1940s,” junkscience.com, November 23, 2016
John Turner et al., “Absence of 21st century warming on Antarctic peninsula consistent with natural variability,” Nature, 535, 411, July 2016
Jack Dini is author of Challenging Environmental Mythology. He has also written for American Council on Science and Health, Environment & Climate News, and Hawaii Reporter.
