Comments 1 to 12:

1. Alexandre at 23:05 PM on 22 August, 2010
   Now that's a great analogy. I'll definetly use this one.
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2. Ned at 00:42 AM on 23 August, 2010
   Are those highs and lows for stations worldwide? In the US only? The graphic has a map of the US as its background ... Might be helpful to include a link to the source of the graphic.
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   Response: It is US only. The paper it comes from is Meehle 2009. It's referenced in the intermediate rebuttal - we're still mulling over how much detail to include in the basic version - whether to include references or just link to the intermediate version for all the nitty gritty details.
3. johnd at 02:09 AM on 23 August, 2010
   You've immediately confused the issue. Firstly you correctly state that to determine trends in climate, the changes in weather needs to be looked at over a long time span, then immediately provide a graph that uses the last 3 decades to support it. Three decades is far from long enough in determining either weather or climate trends when weather cycles have been identified where the rise and fall of the tides in a manner of speaking, takes 6 or 7 decades to complete both phases, in and out as it were, and reconstruction of El-Nino events indicate that perhaps any changes in the "tidal" frequency of them needs to be considered in terms of centuries. However, identifying any trends will always be the easy part, understanding what any trends and cycles mean and why they occur is the hard part. The tide analogy gives opportunity to consider whether the forces that drive the tides that affect even very small bodies of water, has what affect on the moisture suspended in the atmosphere?
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4. muoncounter at 03:29 AM on 23 August, 2010
   #3: "Three decades is far from long enough in determining either weather or climate trends" OK, so look at a longer time span: This was made from a recent GISSTemp release going back to 1880. The plateaus represent each time a new high or low (in the temperature anomaly) is set. Hot summers (JJA average) continue getting hotter, but summertime lows don't get any lower; winter (DJF average) record lows don't get any lower than the -0.62 deg C anomaly from 1893.
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5. Eric (skeptic) at 06:42 AM on 23 August, 2010
   The first problem is that records are usually 5C to 10C or more above normal so are caused by weather, not CO2 warming (1C with WV, 0.2 or so without). The second problem is that the records in the chart above were not adjusted for UHIE (it was not mentioned in the paper). Third problem is the chart is U.S. only, too easily influenced by pacific ocean cycles which can result in extremes.
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6. muoncounter at 06:49 AM on 23 August, 2010
   #5: "records are usually 5C to 10C or more above normal so are caused by weather, not CO2 warming" This is a persistent pattern of setting records and hence not weather. Long term trend... increasing CO2? "records in the chart above were not adjusted for UHIE" We've heard that one numerous times. Satellite data show similar temperatures; is there also UHI in satellite data? "too easily influenced by pacific ocean cycles" If ocean cycles were a factor, 1998 would stand out like a sore thumb. Yet it is part of the whole. So that 'problem' won't fly either.
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7. Eric (skeptic) at 19:52 PM on 23 August, 2010
   Your first point may be valid. ON the second, AFAIK, satellites don't measure record temperatures, just averages. If you have a study showing otherwise, please post it. Averages on the surface are adjusted for UHIE, records are not. On 1998, the state record high temperatures peaked at 19 ( http://hallofrecord.blogspot.com/2007/03/us-extreme-temperatures-update.html) Since state records are often set at smaller stations, they are more immune to UHIE. Hence there are far more standing state records from the 1930's than any other decade.
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8. CBDunkerson at 01:00 AM on 24 August, 2010
   Muoncounter, nice graph. I used the same data to run the numbers for 'hottest winter' and found similar results; New record high Winter anomalies were set in: 1882, 1889, 1901, 1914, 1926, 1944, 1980, 1981, 1983, 1988, 1995, 1998, 2002, and 2007. The data clearly indicate that new global record highs are being set with increasing frequency while there hasn't been a new global record low in nearly a century. As to UHI. No study showing that it has skewed temperature records has ever even been WRITTEN... let alone then stood up to scrutiny. Numerous studies of satellite, proxy, and non-urban temperature records have all shown results consistent with the established temperature series. In short, about the only thing which the UHI argument brings to the table is an easy way to identify people who are willing to take a claim with no substantiating data whatsoever as an excuse to ignore overwhelming evidence to the contrary.
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9. Eric (skeptic) at 03:43 AM on 24 August, 2010
   The UHI effect on record temperatures is very real, see http://www.hindawi.com/journals/amet/2010/230365.html for example. I read a study a few years ago (unfortunately cannot locate) where the author did consider the UHIE and determined that the upward trend in high temperature records was larger than could be accounted for by UHIE (that made sense to me). My question is to what extent the chart in the head post is affected by UHIE. The author did not mention it in his paper.
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10. lciattaglia at 00:14 AM on 2 September, 2010
    I remember reading a text on physical climatology a comparison aimed at representing the temporal dimensions of climate and climate change thus conceived: Suppose that the climate is represented by a natural forest and man is an ant. A natural forest is usually composed of areas where the plants are denser and some clearings, then to the edge of the forest clearings are increasingly extended until the wood ceases. Imagine that the ant is on its way through the forest and try to figure out where it ends. Whenever the vegetation thins out and is a grassy bushes or an open space the ant will be led to believe she get to the forest’s end. The same thing would happen to us if we wanted to assess climate change of the Earth with the lifespan we cross and judging the climate change on the basis of our "time meter”
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11. adelady at 10:53 AM on 2 September, 2010
    Iciattaglia, we all know that. Noone thinks that the earth itself is in danger of expiring. The climate change that concerns us is this climate and its stability. This climate phase has allowed humans to thrive and flourish because it suits the temperature range we can live in comfortably and it suits the kind of plants that sustain life. Our kind of abundant life, not the kind of life that just survives in ice or fire or sitting atop an undersea volcano. Your argument is about geology and time frames of many millions of years. We're concerned about biology and timeframes of centuries or millennia.
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12. lciattaglia at 23:20 PM on 4 September, 2010
    Adelady,I wanted simply to suggest that our lifespan ( or what we remember of the past) is not the correct meter for interpreting the meteorological episodes as a proof of the climate change…. My post had the intention to support the previous one (posted by keepingitreal) on waves and tides.
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