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09-10-2019, 10:53 AM #1276Banned
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I'm still not sure to what you are referencing my use of GISS data from, but it's funny you accuse me of cherry picking from a fraudulent source when you posted a clearly fake GISS graph that only showed .3'C warming in the first half of the 20th century.
I have been using this paper as evidence against your statement that "a warming period is now affecting the whole planet at the same time for the first time." The graph in this paper clearly shows that warming is NOT affecting the WHOLE planet at the same time. It is affecting most of the planet, but that was never a point of contention.
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09-10-2019, 10:58 AM #1277Banned
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09-10-2019, 11:11 AM #1278
- You falsely claimed warming was greater from 1920-1945 than it was from 1980-today
-- You posted a similar graph after accusing me of posting a fake graph. Your graph was essentially the same as the graph you accused of being fake. Then you posted another graph after saying "I didn't post the right graph" with a different timescale but was once again essentially the same over equivalent time periods.
--- You posted the paper to show "global warming hasn't been uniform across the globe." If you want to argue 98% of the planet is warming or the entire planet except the northern tip of Greenland & areas of Andes then that's fine because my statement was always intended in the context of 98% of the planet.
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09-10-2019, 11:18 AM #1279
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09-10-2019, 11:42 AM #1280
NATURE 24 JULY 2019
"The aberrant global synchrony of present-day warming"
Were extended warm or cold periods in the past worldwide, or only regional? Efforts to reconstruct Earth’s climate history suggest that the near-global extent of ongoing warming is unparalleled over the past 2,000 years.
Abstract
Earth’s climate history is often understood by breaking it down into constituent climatic epochs1. Over the Common Era (the past 2,000 years) these epochs, such as the Little Ice Age2,3,4, have been characterized as having occurred at the same time across extensive spatial scales5. Although the rapid global warming seen in observations over the past 150 years does show nearly global coherence6, the spatiotemporal coherence of climate epochs earlier in the Common Era has yet to be robustly tested. Here we use global palaeoclimate reconstructions for the past 2,000 years, and find no evidence for preindustrial globally coherent cold and warm epochs. In particular, we find that the coldest epoch of the last millennium—the putative Little Ice Age—is most likely to have experienced the coldest temperatures during the fifteenth century in the central and eastern Pacific Ocean, during the seventeenth century in northwestern Europe and southeastern North America, and during the mid-nineteenth century over most of the remaining regions. Furthermore, the spatial coherence that does exist over the preindustrial Common Era is consistent with the spatial coherence of stochastic climatic variability. This lack of spatiotemporal coherence indicates that preindustrial forcing was not sufficient to produce globally synchronous extreme temperatures at multidecadal and centennial timescales. By contrast, we find that the warmest period of the past two millennia occurred during the twentieth century for more than 98 per cent of the globe. This provides strong evidence that anthropogenic global warming is not only unparalleled in terms of absolute temperatures(5), but also unprecedented in spatial consistency within the context of the past 2,000 years.
Because thermometer measurements of air near Earth’s surface before AD 1850 are not widely available, we rely on archives of proxy data to extend our perspective on climate further back in time. Trees in cold Arctic or alpine forests have annual rings with widths and wood densities that reflect year-to-year variations in summer temperature5. And because the chemical make-up of seawater depends on its temperature, massive corals build endoskeletons that contain a permanent geochemical record of past warming and cooling6. Other geological and biological archives that encode temperature information into their physical structure, substance or geochemical composition include lake sediments, glacier ice and bivalve molluscs (such as clams, oysters and mussels). Such archives likewise serve as ‘palaeothermometers’ that record temperatures stretching hundreds or thousands of years into the past.
Neukom et al. weave all of this evidence into a detailed global portrait of surface temperatures that spans the past two millennia. The foundation for their work is provided by the PAGES 2k proxy temperature database7. This community-sourced compilation includes nearly 700 records from trees, ice, sediment, corals, cave deposits, documentary evidence and other archives. Partly because the database incorporates so much information, the authors can chart the geographical extent of unusually warm or cold conditions across the entire planet by year.
The team reports in Nature that, although the Little Ice Age was the coldest epoch of the past millennium, the timing of the lowest temperatures varied from place to place. Two-fifths of the planet were subjected to the coldest weather during the mid-nineteenth century, but the deepest chill occurred several centuries earlier in other regions. And even at the height of the Medieval Climate Anomaly, only 40% of Earth’s surface reached peak temperatures at the same time. Using the same metrics, global warming today is unparalleled: for 98% of the planet’s surface, the warmest period of the Common Era occurred in the late twentieth century — the authors’ analysis does not encompass the continued warming in the early twenty-first century, because many of their proxy records were collected more than two decades ago.
In 2005, palaeoclimatologists John Matthews and Keith Briffa1 cautioned against deeming the Little Ice Age an “uninterrupted, globally synchronous, cold period”. These new results certainly bolster their point of view. And we can be confident in that conclusion because Neukom et al. carried out an exhaustive set of experiments to confirm that their findings were unaffected by their choice of statistical tools to relate the proxy network to thermometer measurements.
Unfortunately, limitations inherent in the proxies themselves probably still hamper our ability to compare warm or cool intervals with each other throughout the entire Common Era. Tree-ring records, the most frequently used proxy archive in the PAGES 2k database, are sometimes unreliable in registering slow climate changes over several centuries or longer8. Moreover, some other proxies — particularly records from marine and lake sediments — exaggerate variations at multidecadal or centennial timescales9,10. It is still an open question how well we can compare global temperatures across this entire 2,000-year span.
We can be more certain of how and why Earth warms or cools over decadal and multidecadal timescales. In their companion paper in Nature Geoscience, Neukom et al. show that, in the pre-industrial period (AD 1300–1800), major volcanic eruptions (or the lack of such eruptions) were the main factor behind cold (or warm) swings that persisted for several decades. Shifts in greenhouse-gas concentrations had a smaller, but still detectable, imprint. The team found no indication that variations in the Sun’s radiation output affected mean global temperature over the same time frames.
In general, physics-based climate models accurately reproduce proxy estimates of our climate’s history over the past millennium. However, these models exaggerate the degree of cooling caused by the two largest volcanic eruptions of the Common Era: the AD 1257 Samalas and the AD 1815 Tambora eruptions in Indonesia11. This discrepancy implies that we cannot be sure how bitter a chill would follow a similar eruption in the future.
The familiar maxim that the climate is always changing is certainly true. But even when we push our perspective back to the earliest days of the Roman Empire, we cannot discern any event that is remotely equivalent — either in degree or extent — to the warming over the past few decades. Today’s climate stands apart in its torrid global synchrony.
Nature 571, 483-484 (2019)
doi: 10.1038/d41586-019-02179-2Move upside and let the man go through...
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09-10-2019, 12:27 PM #1281
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09-10-2019, 12:41 PM #1282
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09-10-2019, 01:26 PM #1283Been there, skied that.
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"Quote Originally Posted by iceman View Post
Ron's gettin' a bit frantic. A change of heart is in the offing. So Ron, what planet do your kids plan on inhabiting? If it's this one, you might want to start thinking harder."
please no, this is one of my favorite threads on tgr. it's mostly ticks arguing on a dogs behind; but still funny.TGR forums cannot handle SkiCougar !
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09-10-2019, 01:32 PM #1284Registered User
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Here you go Ron, I found a source that would be easily digestible for you. It's not the magnitude of warming, it's how fast it's happening.
https://xkcd.com/1732/
Also, tits, ski shots, or GTFO.
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09-10-2019, 02:27 PM #1285
So you're saying Ron has a chance. . .
"Only one-in-a-million chance global warming is not manmade, scientists say"
Evidence for man-made global warming has reached a “gold standard” level of certainty, adding pressure for cuts in greenhouse gases to limit rising temperatures, scientists said.
“Humanity cannot afford to ignore such clear signals,” the US-led team wrote in the journal Nature Climate Change of satellite measurements of rising temperatures over the past 40 years.
They said that confidence human activities were raising the heat at the Earth's surface had reached a “five-sigma” level.
This statistical measure meaning there is only a one-in-a-million chance that the signal would appear if there was no warming.
Such a “gold standard” was applied in 2012, for instance, to confirm the discovery of the Higgs boson subatomic particle, a basic building block of the universe.
Benjamin Santer, lead author of the study at the Lawrence Livermore National Laboratory in California, said he hoped the findings would win over sceptics and spur action.
“The narrative out there that scientists don't know the cause of climate change is wrong,” he said. “We do.”
Mainstream scientists say the burning of fossil fuels is causing more floods, droughts, heat waves and rising sea levels.
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09-10-2019, 02:29 PM #1286
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09-10-2019, 02:46 PM #1287Banned
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-I did not mean to claim the warming was greater from 1920-1945 than 1980-today. My point was to show that the earlier warming is comparable to the recent warming. I'm not sure where in the thread you got this quote from me from:
"In any case, take a look at the GISS data yourself. It doesn't even show what they are saying. It has steady temps 1880-1920, ~.6' warming 1920-1945, steady temps 1945-1980, then ~.5' warming 1980-today," but I'm guessing it must have been based off a GISS graph that must not have been totally recent (up to 2010?).
In any case, if we use the most recent GISS data, you can still see that the earlier warming is still comparable to the recent warming: https://data.giss.nasa.gov/gistemp/graphs_v4/
The warming from 1909 to 1944 is +.69'C. No warming until 1977 to high point in 2016 of +.84. 1909 to 1944 has an average warming rate per year of .0197'C. 1977 to 2016 has an average warming rate of .0215'C. Very comparable.
--I first posted an accurate GISS graph, which included other similar temperature records, that did not have the smoothing of your graph. It didn't make for a good comparison so I replaced it with the same GISS data graph, but included smoothing to make it easily comparable to your fake graph.
---The graphs from the paper do not show 98% of the planet is warming. I'm willing to concede to you that 98% of the planet may as well be the entire planet. The data from that paper shows ~10% of the planet is not warming.
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09-10-2019, 02:52 PM #1288Banned
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This is the paper MultiVerse and I have been arguing about for days now.
Multi, notice the section I bolded. This has been a major point of contention of mine. There are major data barriers preventing such definitive statements from you on how unprecedented this warming is compared to the past.
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09-10-2019, 02:54 PM #1289Banned
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09-10-2019, 03:01 PM #1290Banned
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09-10-2019, 03:03 PM #1291
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09-10-2019, 03:26 PM #1292Registered User
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"[with?] " is not needed there. "Confidence" is a reference to the statistical confidence level. In other words, the confidence level that human activities are raising the heat at the Earth's surface has reached 99.99994%.
Not sure what we're arguing about, TBH, because you said that you and 99% of skeptics agree with that statement. Sounds like we're all on the same page!
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09-10-2019, 03:27 PM #1293Registered User
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09-10-2019, 04:29 PM #1294Banned
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It's cherry picked to capture the two distinct warming phases starting with the lowest average temperature of the 20th century. If you want to choose 1950 as your starting point for the second warming period you get 1.2' of warming, but the yearly average rate of warming is less at .0181'C/year.
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09-10-2019, 04:49 PM #1295Banned
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This has been your position that I take issue with:
Anyway, this is what a broad cross section of data and models indicate:
1. Average global temperatures in the 20th century are higher than ever before in at least 2,000 years
2. A warming period is now affecting the whole planet at the same time for the first time
3. And the speed of global warming has never been as high as it is today.
You do not have a preponderance of evidence to make these claims. Your preponderance of evidence is largely one single paper, which has clear data reliability issues.
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09-10-2019, 04:51 PM #1296Banned
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09-10-2019, 04:53 PM #1297Banned
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09-10-2019, 04:54 PM #1298
- You argued earlier in this thread that warming prior to 1950 did occur in a globally uniform (spatially-temporally) way but that's not what the charts in your paper show and that's not what the contents of your paper say.
-- If your argument is a warming period is now affecting 90% of the planet that's progress, even though it's not in agreement with the paper's written content: "except for the weak cooling in the northern tip of Greenland and in the vicinity of the Andes, almost all the global land had been warming."
--- The reason why it matters is the slow-varying nature of the warming in the second half of the twentieth century is "consistent with the slowly increasing carbon dioxide in the atmosphere."
---- Your paper essentially supports the second point that a warming period is now affecting, for the sake of argument 90%-to-98%, of the planet at the same time for the first time.
----- Making it four papers referenced in this thread, not one. And a key point you ignore is several of the papers make use of an expanding open access database. It's the best evidence currently available of the planet's warming and spatiotemporal variability.Last edited by MultiVerse; 09-10-2019 at 07:57 PM.
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09-10-2019, 05:12 PM #1299Registered User
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The sources are included, it's XKCD, not a Fox infographic - look at the top right. Links below for your reading pleasure.
https://www.nature.com/articles/nature10915
https://science.sciencemag.org/conte.../1198.abstract
Annan and Hargreaves (2013)
IPCC
Looking forward to your carefully considered conclusions , though I imagine you can give your conclusions without reading the sources
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09-10-2019, 05:14 PM #1300Banned
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