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Complexities of climate change
There's more to the issue than a warming world and rising sea level
Posted May 30, 2008
A chunk of the Wilkins Ice Shelf along the Antarctic Peninsula breaks off, leaving the rest of the floating ice slab, roughly the size of Connecticut, hanging by the proverbial thread. Next summer, maybe in three, the Wilkins will become the latest in a series of West Antarctic ice shelves to slough away from the continent.
The disintegration, which started in February, caught scientists by surprise by its timing and rapidity. Many thought the ice shelf would be safe for several more decades.
Elsewhere in the world, glaciers are retreating and ice caps shrinking quicker than anyone could have predicted even five years ago. Book your trip to Mount Kilimanjaro today, because the glaciers on Africa’s highest mountain probably won’t survive past 2020 if predictions prove true.
Tourists will have to visit Lonnie Thompson’s cold storage facility at Byrd Polar Research Center (BPRC) at The Ohio State University to see ice from Kilimanjaro. Thompson and colleagues have made several trips to the 5,895-meter peak to collect ice cores in an effort to save the unique climate record stored in the ice before it disappears.
His estimate of 2020, recently revised to as early as 2015, illustrates that the climate prediction game remains an inexact science. In Antarctica, where temperatures have soared along the peninsula in the last several decades but have changed little over East Antarctica, projecting the future has proven even more difficult, but vital, considering the amount of water stored in the continent’s ice sheets.
“Can we ever know enough fast enough in order to actually predict? And if we did predict, would there be any response by human beings to adapt to these things?” Thompson muses during an interview at BPRC, following a planning session with his team about an upcoming trip to the Peruvian Andes.
“How fast can these glaciers actually flow into the ocean and change sea level? How fast can sea level rise?” he continues in the rhetorical vein, noting the scientific questions serve pragmatic purposes: “People want to know how high they need to build bridges.
“What we’ve learned is how much we don’t know,” he says. “Ten years ago people wouldn’t believe a glacier could increase its speed twofold in one year.” Those glaciers, he notes, can actually flow eight times faster.
“I think [the Intergovernmental Panel on Climate Change] was very conservative,” he adds. “It didn’t take into account any of this rapid response.”
The Intergovernmental Panel on Climate Change (IPCC) is a scientific body under the auspices of the United Nations. Its mission is to assess peer-reviewed scientific literature related to climate change, its impacts and strategies to mitigate possible effects. Its most recent report, released last year, bluntly warned, “Warming of the climate system is unequivocal.”
The IPCC concluded, “Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (human) greenhouse gas concentrations.”
World temperatures, the IPCC said, could rise by between 1.1 and 6.4 degrees Celsius during the 21st century and that sea level will probably rise 18 to 59 centimeters. It’s the sea level rise number that Thompson and others have criticized.