Ice Memory

I recently read an interested article titled “Ice Memory” in The New Yorker by Elizabeth Kolbert. The article was published in early 2002 and is set in North-central Greenland where, in the summers of 1996 through 2003, scientists drilled an ice core from the top of a glacier down to bedrock at 3085 meters. The ice core encases a climate record back to around 123000 years before present.

The project was called the North Greenland Ice Core Project (NGRIP) and was created to produce an ice core to reproduce (or possibly not) the results obtained from cores extracted by earlier projects, particularly the core produced by the Greenland Ice Core Project (GRIP).

The article covers many topics including recent shifts in the understanding of the climate, a history of Greenland — specifically the first known European settlement of Greenland by the Norse, the objectives of NGRIP, daily life on the ice, and what the ice can tell us.

Central to the article are the startling observations (resulting from the study of earlier ice cores) of extremely abrupt changes in average temperature several times over the last 100000 years. Kolbert writes:

Around fifteen thousand years ago, Greenland abruptly warmed by sixteen degrees in fifty years or less. In one particularly traumatic episode some twelve thousand years ago, the mean temperature in Greenland shot up by fifteen degrees in a single decade.

The story ends considering the relationship between the rise of human civilization and the information extracted from Greenland ice cores.

I have not read enough to know how much agreement there is on the results from Greenland ice cores or what the sticking points are, but in spite of that, the story is quite interesting. More context would, however, be nice.

Since I read this piece more than six years after publication, I wondered what results had come out of the effort, specifically with regards to “Eemian Ice Age Event One”. A paper, “High-resolution record of Northern Hemisphere climate extending into the last interglacial period“, authored by the NGRIP members and published in Nature in 2004, reports that the GRIP ice core that led to the observation of Event One was contaminated by “ice folding”.