|
Post by icefisher on Jan 5, 2010 3:26:00 GMT
My argument has always been that there has never been any good evidence that says that there was a period during the MWP era (900-1350) that was globally warmer than now. What you mean to say is you have not seen any good evidence. That shouldn't be so surprising because actually you haven't seen good evidence that the 2000's was warmer than the 1940's. Steve McIntyre said 2 and a half years ago "At this point, I’m not arguing that a MWP is established world wide, but that the arguments against it are flawed." Steve McIntyre is a smart enough man to only comment on what he has worked upon.
|
|
|
Post by spaceman on Jan 5, 2010 4:39:09 GMT
So far, the East Coast has had a bitterly cold winter -- there's no debating that. Temperatures were below normal throughout the region between New York City and Atlanta, says Mike Pigott, meteorologist at AccuWeather, who says the extreme cold is likely to linger through February.
Global Warming Means Big Blizzards
And the cold snap would be worse if not for global warming, says Brenda Ekwurzel, a climate scientist from the Union of Concerned Scientists. In fact, she says, "Blizzards and big snowfalls are entirely consistent with global warming," because warmer air traps moisture in clouds, leading to more intense blizzards.
A perfect Algoreithm!!!! Never mind the fact that it freaking freezing!!! What happened to the runaway greenhouse effect? This is a theater of the absurd. Oranges are freezing in Florida and yet somehow if it weren't for global warming it would be colder? Helloooo, what's making it colder in the first place?
Let's see 1. The underlying trend is warmer. 2. The heat's in the pipeline. 3. Whatever happens, it's because of AGW. I think there is a divergence between fantasy and reality. AGW science fanasty is going one way and reality another.
|
|
|
Post by hairball on Jan 5, 2010 4:52:42 GMT
|
|
|
Post by sentient on Jan 5, 2010 5:06:55 GMT
I thought those were mann-made blizzards? ??
|
|
|
Post by poptech on Jan 5, 2010 5:42:20 GMT
The '338' sources listed in the title of this thread refers to the number of links in the above blog to references on cooling in 2009 (up to 375 sources at the time of this post, though as some of those links are themselves blog entries reporting what some of the other links state, the number is artificially inflated). Actually that is not true, none of links are reporting the same thing and thus nothing is artificially inflated. There are 375 sources.
|
|
|
Post by nautonnier on Jan 5, 2010 9:00:05 GMT
Well indeed! The only data we have about the Holocene is imperfect proxy data which doesn't say what you would like it to say. The fact that the temperature may be variable without CO2 change doesn't help your claim that there must be an inbuilt mechanism preventing variability, or prove that CO2 cannot have any effect. The fact that some of our ancestors survived climate change in the past does not mean that some of them didn't - though ancient humans were probably more adaptable. Since a lot of our current infrastructure (cities, buildings, transport and power infrastructure) will need to be protected and upgraded to deal with any CO2-induced changing climate, comparisons are not that meaningful. "The only data we have about the Holocene is imperfect proxy data which doesn't say what you would like it to say"Unlike AGW proponents - I do not want "data to say" anything - I would just like the raw data without someone having modified or adjusted it - as with the Darwin temperature recordings; or chosen which ones to use and which to discard - as with the Russian temperature sites. It has got to the stage where it is difficult to trust any established 'fact' in climate 'science'. What I was asking for was an agreed Holocene long baseline that was generated using fully and openly validated proxies. Validated against the ~200 years of actual temperature measurements or against other proxies that have been validated against those metrics. As many of the arguments are that the current time is 'exceptional' in some way then it makes sense to verify that claim. From geological records of the Holocene it appears that there is NOTHING in current temperature changes that is exceptional, and temperatures appear to be below the Holocene average. Similarly with CO2 concentrations are unexceptional and even perhaps low compared with geological record. So everyone should use as their baseline 10,000 year averages based on validated metrics. Putting a Holocene average line on the graphs at the beginning of the thread would show the baseline temperature above the temperatures shown in both graphs. "The fact that the temperature may be variable without CO2 change doesn't help your claim that there must be an inbuilt mechanism preventing variability, or prove that CO2 cannot have any effect."I have not claimed that CO 2 has no effect but I have claimed that it has not been proven in a real atmosphere and that there is no experimental evidence that CO 2 has the same effect as the hypothetical comparator construct 'radiative forcing'. One way to assess this is to look at CO 2 concentrations over the Holocene or longer and check for apparent causality. When these longer timescales are used if there is any causality it appears to be that temperature causes CO 2 rise. This is in agreement with Henry's Law and is unsurprising. It would also be in agreement with the current warming - resulting in the monotonic rise in CO 2 shown in all the Mauna Loa graphs as the system tends toward the balance between vapor pressure and outgassing due to sea surface temperature rise. " The fact that some of our ancestors survived climate change in the past does not mean that some of them didn't - though ancient humans were probably more adaptable. Since a lot of our current infrastructure (cities, buildings, transport and power infrastructure) will need to be protected and upgraded to deal with any CO2-induced changing climate, comparisons are not that meaningful"The reason the AGW proponents NEED the MWP and the Roman optimum to 'not exist' is that they show how panic about these higher temperatures is invalid. From history and archaeological findings we see that there were birch forests in Northern Greenland when the Vikings settled there. There were other tribes settled all around Greenland the ice sheet was less extensive then than it is now. London which was in existence at the time without a Thames barrier - was not flooded. Amsterdam which was a thriving port at the time - was not flooded. So your concern about littoral cities dealing "with any CO2-induced changing climate" appears to be baseless. There are problems with some that are moving tectonically such as Southern UK or due to unwise extraction of ground water such as New Orleans but these are not examples of potential world wide inundations. Indeed the mean sea level mark in Port Arthur Tasmania seems to indicate little change. So to recap - the use of a long baseline as a comparator would impose a more realistic approach and response to climate changes and their effects.
|
|
|
Post by Graeme on Jan 5, 2010 10:25:05 GMT
The '338' sources listed in the title of this thread refers to the number of links in the above blog to references on cooling in 2009 (up to 375 sources at the time of this post, though as some of those links are themselves blog entries reporting what some of the other links state, the number is artificially inflated). Actually that is not true, none of links are reporting the same thing and thus nothing is artificially inflated. There are 375 sources. I stand corrected. I made a rash statement after a cursory look and noticed blogs mixed with news reports, and assumed that the blogs would be covering the same details as the news reports. A closer examination of the list shows otherwise. Thanks for the correction!
|
|
|
Post by steve on Jan 5, 2010 10:46:00 GMT
So he's flown by without a comment on how he manufactured his graph.
Graeme, I take your point that the other graph is supposed to be Jan-Nov data. I didn't expect addition or subtraction of December data would affect variability much so it didn't really affect the point I was making that the source could not possibly be what was being implied (ie. global data from the NCDC).
As for "spin" though, individual models show similar sort of variability (eg. 10 years of no warming or some cooling) to what has been observed, so it is not unexpected that we would see the same.
That said, scientists do not know what explicit factors have caused this "lull" in warming and can only speculate on solar cycle effects, ocean currents and the like. I'm sure they've tried to "spin" it. But they've also tried to understand it. That, I think, is more admirable than just cherry-picking the two years that give you the biggest cooling trend and saying "warming has stopped", "cooling has started" and "the models cannot explain it" which are all arguably true statements, but are made to mislead rather than to explain.
|
|
|
Post by raveninghorde on Jan 5, 2010 10:52:29 GMT
Well indeed! The only data we have about the Holocene is imperfect proxy data which doesn't say what you would like it to say. The fact that the temperature may be variable without CO2 change doesn't help your claim that there must be an inbuilt mechanism preventing variability, or prove that CO2 cannot have any effect. The fact that some of our ancestors survived climate change in the past does not mean that some of them didn't - though ancient humans were probably more adaptable. Since a lot of our current infrastructure (cities, buildings, transport and power infrastructure) will need to be protected and upgraded to deal with any CO2-induced changing climate, comparisons are not that meaningful. There is good data with real temperatures, not anomalies, from Central Greenland published by Richard Alley in 2000. I have plotted it here: www.zen88234.zen.co.uk/climate/gland.htmData from: www.ncdc.noaa.gov/paleo/pubs/alley2000/
|
|
|
Post by steve on Jan 5, 2010 12:04:28 GMT
Nautonnier You now have access to the raw data. It appears to give similar trends. For every station that gives a lower trend there would seem to be another station that gives a higher trend. The homogonisation process has clearly been even-handed. I do not understand this point at all. Many of the criticisms of the hockey stick et al relate to the difficulty of making assertions about the relationship with absolute temperature (as opposed to short term variability) when you go further and further back in time. You appear to want to deny the various tree-ring and non-tree-ring proxy reconstructions that show no global MWP, yet accept even more uncertain older proxy data. Here is an example graph of some of the data. Note that the black line is *not* a true "global average temperature - it is just an average of the proxies shown: en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.pngYou are assuming that the apparent warmth observed in parts of Greenland was global. And the evidence is just not there. Given that you cite evidence of non-flooding of cities I would challenge you to research the development of a number of cities and ask yourself whether evidence of flooding would have survived in the historical record. Our ancestors maybe weren't dumb enough to build on flood plains.
|
|
|
Post by sigurdur on Jan 5, 2010 12:25:38 GMT
It seems that the MWP only happened in North American and Europe. Ok, China too. OK....just read that Argentina also experienced it.
So we can see that it was selective and only occured in the Northern Hemisphere and the Southern Hemisphere.
|
|
|
Post by boxman on Jan 5, 2010 14:49:41 GMT
If you could point me to a post where I claimed that the Hockey Stick was an accurate representation of the last millennium temperatures, then I'll give you an answer. My argument has always been that there has never been any good evidence that says that there was a period during the MWP era (900-1350) that was globally warmer than now. I am utterly unqualified to judge whether the Hockey Stick analysis was done correctly or appropriately (given what was known in 1998). I've checked this by digging out some posts I made on climateaudit in 2007. IIRC, Mann and Briffa seem to have argued strongly about the issue in the stolen emails, but Briffa's view (a long time ago) was only that it may have been that Northern Hemisphere summers may have been warmer (which may not be a surprise given that the northern latitudes received more summer sunlight then). Steve McIntyre said 2 and a half years ago "At this point, I’m not arguing that a MWP is established world wide, but that the arguments against it are flawed." Which seems to concur with what I said, though it does put the cart before the horse by half-implying that an MWP is an accepted fact that is there to be disproved. climateaudit.org/2007/05/15/swindle-and-the-ipcc-tar-spaghetti-graph/#comment-88194They have also found evidence of MWP in Antarctica as well as other regions in the southern hemisphere.
|
|
|
Post by Graeme on Jan 6, 2010 0:00:02 GMT
So he's flown by without a comment on how he manufactured his graph. Graeme, I take your point that the other graph is supposed to be Jan-Nov data. I didn't expect addition or subtraction of December data would affect variability much so it didn't really affect the point I was making that the source could not possibly be what was being implied (ie. global data from the NCDC). I think I can state with a high degree of certainty that the graph is not the global data from the NCDC. It doesn't even appear to be the global land, or northern hemisphere land data, either. It's quite possible that the data being graphed is from the NCDC, but without knowing what set of data was selected, we can't comment on the relevance. It may be, taking a very silly example, a graph of the data from a weather station in Upper Mongolia.... Accurate NCDC data, but not particularly relevant from a worldwide perspective.
|
|
|
Post by brian0707 on Jan 6, 2010 1:08:55 GMT
If one throws out the climate reconstructions of the Mann, Briffa faction, the older - and newer - scientific body clearly supports a worldwide MWP.
I realize this is a very broad statement but suggest those skeptical of it simply start reading. Start for example with latitudinal and altitudinal tree-line studies (note tree lines not tree rings).
These invariably show that on all continents, tree lines extended higher- latitudinally and altitudinally - during the MWP than today. The highest recorded tree line elevations occured during the holocene thermal maximum a few thousand years ago. So, historically speaking, today's climate is well within recent and slightly older historical ranges.
Climactically speaking, tree lines seem to me to be much more honest climate proxies than tree rings - being influenced primarily by temperatures rather than temperatures, precipitation, soil conditions and surrounding flora. Their limitation is that they don't offer proxies on annual time scales.
Its also worthy of note that many of the high latitude tree ring proxies used by Mann and Briffa came from preserved dead trees extracted from the permafrost. An interesting irony.
|
|
|
Post by icefisher on Jan 6, 2010 9:04:46 GMT
That said, scientists do not know what explicit factors have caused this "lull" in warming and can only speculate on solar cycle effects, ocean currents and the like. I'm sure they've tried to "spin" it. But they've also tried to understand it. That, I think, is more admirable than just cherry-picking the two years that give you the biggest cooling trend and saying "warming has stopped", "cooling has started" and "the models cannot explain it" which are all arguably true statements, but are made to mislead rather than to explain. You have a short memory Steve. What happened to "This warming is unprecedented", "CO2 forcing has overridden natural variation"; and the models provide a realistic view of 1.5degC to 4.5degC warming over the next century" ? Not to speak of words coined like "denialists", "flat-earthers", "in the pay of oil companies". . . .etc. Were those to mislead or explain?
|
|