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Greetings John, While I share a deep concern and alarm over what is happening in the Arctic, it is important that we are accurate in our descriptions of it. I noticed a few minor discrepancies between your post and impressions I have gleaned from my own reading. "The end of the sea ice is clear, with downward trend established on volume and a record minimum extent today." I assume you meant the other way around: a new record minimum <i>volume</i> and a downward trend on <i>extent</i>. As I understand it, extent this year is likely to end up slightly higher than 2007, though depending on weather conditions over the next couple of weeks, the extent record might still fall. A record for lowest Arctic sea ice area is an even higher chance (area and extent are separate metrics, though the latter is more widely quoted and discussed). You can follow the progress of the various metrics here: http://www.realclimate.org/index.php/archives/2011/09/arctic-sea-ice-minimum-discussions/ "When the end summer is free, we'll be about 70% of the way, from PIOMAS expected 2015 more likely than 2016" I assume you are referring to the quadratic binomial trend fitted to the graph in your second link. Neven (who put it together) acknowledges in your first link that in practice it is very unlikely to follow the curve all the way down, as negative feedbacks will likely result in some small amount of sea ice clinging on to the coast of Greenland for some time. The same applies to winter maximum predictions of around 2020. While these declines are indeed alarming, there is no point giving hostages to fortune with relatively unlikely predictions. "The forcing produced corresponds to those percentages." Doesn't the forcing relate pretty much exclusively to summer sea ice, since albedo has little role to play during an Arctic winter? "And, as that forcing increases, the Arctic warming accelerates" Do you simply mean that as the forcing increases the Arctic warming increases or are you suggesting that there is a non-linear relation between forcing and warming? Are you also aware of a recent <i>Nature</i> study that suggested that earlier fears of an overwhelming positive Arctic albedo feedback may have been premature? http://www.nature.com/nature/journal/v468/n7326/full/nature09653.html Grace & peace, Byron Smith PhD candidate in Christian Ethics School of Divinity Edinburgh University