July 26, 2012
Greenland Ice Sheet Melt Unprecedented
by Robert Kropp
NASA satellite measurements confirm that 97% of Greenland's ice sheet has melted this summer, far
more than ever before recorded.
Climate scientists are wary of attributing singular weather events to the effects of climate
change. So even when NASA satellite photographs depict
an "unprecedented" melting of Greenland's ice sheet—an estimated 97% of the ice sheet surface had
thawed by mid-July, compared to an average of about half—some scientists seek to attribute the
phenomenon, at least to an extent, to other causes.
Ice core analyses of the area
around Summit Station in central Greenland, located near the highest point of the ice sheet,
indicate that pronounced melting has occurred there as well, for the first time since 1889. "Ice
cores from Summit show that melting events of this type occur about once every 150 years on
average. With the last one happening in 1889, this event is right on time," Lora Koenig, a
"But if we continue to observe melting events like this in
upcoming years, it will be worrisome," she continued.
Additional data compiled by NASA
suggest that the time for worry may be upon us. Between 2003 and 2010, the data reveal, the average
ice mass in Greenland declined by more that a trillion tons.
And while the mid-summer ice
melt is caused by the predictable arrival of a heat dome over Greenland, "Each successive ridge has
been stronger than the previous one," said Thomas Mote, a climatologist.
to scientists is that we know the Arctic ice is a key feedback, and the warming in the Arctic has
been slightly faster than was predicted 10 or 20 years ago,'' Karl Braganza of Australia's Bureau
of Meteorology told the Sydney Morning Herald. "This year, we measured CO2 emissions in the Arctic at
above 400 parts per million for the first time. That's the first time it's been at that level in 3
If climate scientists are reluctant to go out on a limb and attribute the
melting ice sheet to climate change, Bill McKibben of 350.org has no such qualms. Writi
ng in Rolling Stone, McKibben reported that temperatures for May in the northern hemisphere
were the highest on record. May, McKibben wrote, was "the 327th consecutive month in which the
temperature of the entire globe exceeded the 20th-century average, the odds of which occurring by
simple chance were 3.7 x 10-99, a number considerably larger than the number of stars in the
"Not that our leaders seemed to notice," McKibben continued, referring to the
lack of progress at last month's Rio+20 conference, described by George Monbiot as
"perhaps, the greatest failure of collective leadership since the first world war."
the challenge of addressing climate falls, to a disproportionate degree, to other actors, including
corporations and the investors that engage with them. Yet according to the recently published
Evolutions in Sustainable Investing: Strategies, Funds and Thought Leadership, even sustainable
investors have been slow to adopt what Nick Robins of the Climate Change Center of Excellence at
HSBC described as "forward-looking, prospective methodology which we argue will systematically add
value over time."