21 March 2009


Whether Greenland is melting or not is a vital issue for future public policy and future human life on this Planet. Below is a brief discussion.

Recently I navigated to a website
http://wattsupwiththat.com/2008/12/30/the-ice-in-greenland-is-growing/ (provided by some global-warming deniers) about ice growth in Greenland (it contends that the Greenland ice sheet [GrIS] is actually increasing; and, therefore, global warming is a myth) and found that it is only anecdotal about snow drifts building up around a DEW radar installation--with a photo to prove it! In addition, to buttress its argument, the website provides a map and reference to a research article by Johannessen et al. (2005. "Recent Ice-Sheet Growth in the Interior of Greenland," Science, 310(5750):1013-1016). I went to that article and read that the researchers measured the altitude of the GrIS above 1,500 meters, between 1992 and 2003, and found that it increased in height an average of 6.4 centimeters per year. Below 1,500 meters the average elevation change was minus 2.0 cm/yr. (the thinning margins of the ice sheet), for an average increase of the entire ice sheet of 5.4 cm/yr.

But, the Johannessen et al. research was not carried out to determine volume, it was simply about height above sea level of two separate regions of the GrIS--interior and margins. And, it makes no sense to average a positive and a negative to arrive at average change for the whole ice sheet, when the interior is a far larger expanse than the narrow (but growing) margins.

So, I found a more recent article (Schuenemann et al. 2009. "Synoptic Forcing of Precipitation over Greenland: Climatology for 1961-99," Journal of Hydrometerology 10) which states, "Recent changes of the GrIS include not only a thickening of the interior of the ice sheet [i.e., it is increasing in elevation in the interior, as the Johannessen article above shows] but also a thinning along the edges" [as the Johannessen above also found]. But, importantly, it goes on to state that, "The most recent analyses have shown AN OVERALL NET LOSS OF MASS because of increasing melt and ice discharge" [my emphasis].

From the above, I conclude that the GrIS is increasing in elevation in the interior, while it is thinning and shrinking at the edges, and that OVERALL there is a decrease in mass. This is the (hugely significant) problem: the Greenland ice sheet is melting overall.

Furthermore, the melting of the GrIS, say Schuenemann et al., "has very likely contributed to the rise in sea level" due to its "capacity to influence global climate..." in several ways.

I thank those deniers for the continuing challenge to find for myself the science of global climate change. I also thank them for the continuing confirmation that there are interests who present anecdotal evidence (e.g. snow drifts building up around a radar site) and link it to research that does not support what the anecdotal evidence purports to say (e.g. the Johannessen et al. article above).

Once again, I feel confident about what science is telling us about global climate change. But, I continue to wonder about the deniers. Why not stay with the science, instead of promoting an anti-science? Believe me, if science begins to tell me that global climate change is not happening, or that the end result might be a global cooling (which is possible, if there is a tipping point with the Greenland ice-sheet melt setting off a reduction of the North Atlantic haline circulation)--or whatever science tells us--then I will believe what the CONSENSUS of scientists tells us.

Why not? To do otherwise is to take an ideological stance that will continue to confuse the public about what science says is happening and will delay critical changes that humanity will have to make if it is to survive. The issue of whether Greenland is melting is one of the critical issues that we must leave to science and not to ideology. It is crucial that we believe the science. It is folly to do otherwise.

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