Once Upon an Ice Cap

By Bruce E. Johansen

Will I live long enough (I am 62) to wake up one morning in September to a headline that reads: ARCTIC ICE CAP GONE? Given what happened this year, the odds are improving. This news story probably will include a disclaimer saying that a single event does not ‘prove’ global warming, and an emphatic denial from someone on an oil-company payroll asserting that the disappearance of the arctic ice cap is a matter of natural variability having absolutely nothing to do with human combustion of fossil fuels.

With our record-warm year, episodes of drought and deluge, and increasing acidification of the oceans, is this what the ‘tipping point’ looks like? Are we passing the point of climatic no return even as public boredom and resignation coupled with deniers’ obfuscation erases the issue from the public agenda?

By late August, with two to three weeks remaining on the seasonal melting clock and a slushy area half the size of Indiana (a quarter of Nebraska) liquefying each day, the ice cap set an all-time low, with only 30 percent of the Arctic Ocean covered. By September 15, when the season’s low was recorded, coverage was down to 24 percent—half that of 1979. Five years ago, various models forecast an open Arctic Ocean in 2050. Now, scientists are projecting complete ice melt about 2020. I will turn 70 that year.

Giving Scientists Chills

“It’s hard even for people like me to believe, to see that climate change is actually doing what our worst fears dictated,” Jennifer A. Francis, a Rutgers University scientist who studies the effect of sea ice on weather patterns, told the New York Times in late August. “It’s starting to give me chills, to tell you the truth.”

A scientist at the “National Snow and Ice Data Center,” Julienne C. Strove, visited the Arctic last summer on a Greenpeace ship, expecting to measure ice floes. She told the New York Times September 20 that she looked in vain for ice that could support her weight. “When we got further into the ice pack,” she said, “there were just large expanses of open water.”

The Greenland ice sheet also has been melting at an accelerating rate. In the meantime, the Northern Hemisphere as a whole experienced its warmest summer (and year) on the instrumental record. Our region, with its record-setting heat and drought conditions, was hardly alone. In the Arctic (in addition to melting sea ice), warmer seasons and a longer summer provokes melting permafrost, which adds carbon dioxide and methane (the two principal greenhouse gases) to the atmosphere. Larger areas of open ocean in the Arctic also absorb more solar radiation than ice cover, contributing to further warming. Scientists call these mechanisms ‘positive feedbacks.’ The average temperature of the Arctic has been rising twice as quickly as that of the planet as a whole. Scientists have a phrase for this: “Arctic amplification.”

This is how the world looks at tipping point.

Add to this the provocations of the fossil-fuel industry, which is joyously rushing into the Arctic to explore for oil under water that used to be ice-covered. At the same time, some of the same companies are exploiting the Alberta tar sands and ‘fracking’ for natural gas from Montana to New York State.

Antarctic Methane

There’s more: as autumn arrives in the Northern Hemisphere, sunshine bathes Antarctica, where relatively warm ocean water nibbles at the continent that stores 90 percent of the planet’s ice. Scientists are looking at the stores of methane that will be released as the Antarctic ice cap gradually melts. Sea levels will rise, of course, as the ocean acidifies, threatening the survival of any living thing with a shell—most notably the phytoplankton at the base of the ocean food chain.

Jemma L. Wadham and colleagues wrote in the British scientific journal Nature this summer: “We calculate that the sub-Antarctic hydrate [methane] inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage.” In addition to all of this, billions of tons of methane lie frozen under what’s left of the Arctic ice cap. Thaw what’s left, warm the ocean enough, and some of that may make its way into the atmosphere. Scientists have an inelegant phrase for this nightmare scenario: “The Methane Burp.”

I know that looking this monster in the eye will be a colossal bore to Republicans who would rather not be bothered by what they have come to regard as a geophysical fairy tale. Denial is an awesome force. Few people enjoy assuming guilt for their role in a major problem, or adjusting their basic behaviors to change it.

Thus, with accelerating natural feedbacks, human contributions to the world’s greenhouse-gas overload acts like the pin on a hand grenade. All the while, our political life continues with only the barest mention of this ticking bomb. In years to come, our descendants may ask what most of us were doing back when life on Earth was tolerable.


REFERENCES

Gilis, Justin. “Sea Ice in Arctic Measured at Record Low.” New York Times, August 27, 2012. [http://www.nytimes.com/2012/08/28/science/earth/sea-ice-in-arctic-measured-at-record-low.html]

Gillis, Justin. “Ending Its Summer Melt, Arctic Sea Ice Sets a New Low That Leads to Warnings.” New York Times, September 19, 2012. [http://www.nytimes.com/2012/09/20/science/earth/arctic-sea-ice-stops-melting-but-new-record-low-is-set.html]

Lemonick, Michael D.Antarctic Methane: A New Factor in the Climate Equation.” The Huffington Post, August 29, 2012. [http://www.huffingtonpost.com/2012/08/29/antarctic-methane-climate_n_1840996.html]

Wadham, J.L., S. Arndt, S. Tulaczyk, M. Stibal, M. Tranter, J. Telling, G.P. Lis, E. Lawson, A. Ridgwell, A. Dubnick, M.J. Sharp, A.M. Anesio, and C.E.H. Butler. “Potential Methane Reservoirs Beneath Antarctica.” Nature 488(August 30l 2012):633-637.

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