The Royal Irish Academy in Dublin was founded in 1785, by royal charter of King George III, as a society for "promoting the study of science, polite literature and the antiquities". Since then, every so often they have held a "Discourse", which means essentially that somebody gives a talk.
This tradition continues at 8 p.m. on Monday night, January 10th, with a Discourse entitled "The Evidence of Global Climate Change Unlocked from Greenland Ice Cores". The speaker will be Prof Sigfus Johann Johnsen, who is currently an Associate Professor at the Department of Geophysics in the Niels Bohr Institute in Copenhagen, but who, as his name suggests, is normally a resident of Iceland. And Prof Johnsen has the unenviable record of having spent 27 of his nearly 60 summers on the Greenland ice sheet.
Let me extract for you the bones of his synopsis: "Glaciers and ice caps grow and shrink, even on continental scales, and change the sea level; they control the Earth's albedo and shape the mountains and the continents on which they rest. But the most peculiar property of glaciers is perhaps their ability to preserve a record of past climatic and environmental change."
Snow falling on the Greenland wastes contains impurities, and these provide a clear signature of the state of the atmosphere at the time. As the snow is transformed into ice, layer by layer corresponding to successive seasons, an almost permanent record is laid down of the climatic history of the period. In addition small bubbles of air trapped within the snow survive the transformation into ice, and provide samples of an ancient atmosphere.
All this information can be unlocked by drilling a very deep hole into the ice-sheet, and extracting, in manageable segments, a narrow cylinder of ice that may be several miles in length. From this long frozen "pencil" the climate of the region back to prehistoric times can be deduced by chemical analysis.
Based on these data, Prof Johnsen's message will be that "our climate system is unstable on most time scales and should definitely be left alone", or, as one of his colleagues in this field has put it more succinctly: "Our climate is an angry beast, and we are poking it with sticks."
Unfortunately one cannot normally stroll up Dawson Street at 7.55 on any Monday evening and expect to enter, without let or hindrance, the hallowed halls of the academy: one has to be invited. But the good news is, I understand, that interested parties who take the trouble to telephone beforehand to (01) 676-2570 may quickly have their name appended to next Monday's guest list.