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Politics : Politics of Energy -- Ignore unavailable to you. Want to Upgrade?

To: enginer who wrote (5477)	2/28/2009 12:46:26 PM
From: Sam	Read Replies (2) \| Respond to of 86356

It is obvious that you didn't bother reading the post that you responded to. Here is the passage that is relevant to your graph: Here’s some input from one ice specialist, Jennifer Francis at Rutgers University, reacting to Mr. Will’s comparison of current ice with 1979 and other assertions: Her general point: This battle never ceases to amaze me. People seem to be much more inclined to believe what they hear from non-experts because it’s what they’d rather hear. Her reaction to the speed of ice recovery from last summer and the extent of polar ice now: This is pretty easy to explain. At the end of summer each year, the sea ice refreezes and continues to do so until late spring. Thin ice and open water generate new ice faster than thick ice, as the heat from the ocean below is able to escape more easily to the atmosphere. In the autumns of 2007 and 2008, the rate of ice production was very large because there was so much open water and thin ice — the rapid growth is completely expected. The other relevant piece of information is that winter ice can only extend so far in the Arctic because the ocean is surrounded almost completely by coast. Once it reaches the coast, it can’t extend any farther. There are only two limited areas where the winter ice edge can vary substantially — the North Atlantic and Bering Sea. In the North Atlantic the ice runs into a branch of the warm Gulf Stream. A significant northward trend (reduction of ice) in the winter-maximum ice edge is apparent, however, and appears to be caused by the gradual warming of sea-surface temperatures in the region (paper available on this if you want it). In the Bering Sea the winter ice edge varies hugely year to year and shows no significant trend. Dr. Francis’s reaction to Mr. Will’s assertion that many scientists saw the global ice changes in a single year as a sign of global warming: Yes, I would agree these are both incorrect. The changes in sea ice in the southern hemisphere (small increase) have been attributed to anthropogenic causes, but in a very different way from what’s happening in the Arctic. The Antarctic ice increase is occurring in a limited region near the Ross Sea, and is related to the ozone hole through a fairly complicated change in atmospheric dynamics. See this brief article in Eos Transactions for a comparison: agu.org Any change in a single year — no matter what the variable — cannot generally be linked to climate change, although the ice losses in 2007 and 2008 would not have happened without the long-term warming and thinning of the ice cover. Yes, I know, it is likely a little to subtle for you to understand. This GW "believers" just rationalize everything, don't they...

To: enginer who wrote (5477)	2/28/2009 6:52:06 PM
From: RetiredNow	Read Replies (1) \| Respond to of 86356

enginer, Thx for posting the chart. However, I don't think you are reading that chart right. I do alot of statistics in my line of work. One heuristic we use to tell quickly from an eyeball chart like this if there is a new trend in the making, is to look at the average trendline and count sequential datapoints above and below the line. If you see, 6 sequential points or more either above or below the average, then you have a new trend. If there are 8 or more, the probability is VERY high you have a new trend. The reason this heuristic works is that if there was no new trend in the making, randomness would mean an equal number of points above and below the line, and the probability would be high you would NOT see 6 or more point sequentially above or below the line. Now let's apply that to the below. take a look at the cluster in the middle of each up/down cycle. It seems to hover around the 20 line until around 1996-7. Then every one of the mid-cycle clusters afterwards, for 12 consecutive years is below the 20 line. 12 years of data being below the previous trendline means there is a very high probability that a systemic change has occurred that has set this process into a new downward trend.