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There have been suggestions that Jo Nova might be trying to hide or ignore the most recent boreholes graph from Huang et al. So here it is. This is the last 2,000 years according to 6000 boreholes, with the last 100 years also using the “instrumental record” which gives us that hockey-stick uptick at the end. Below I explain the pros and cons of this study and update my thoughts.
Huang and Pollack 2008: Their latest boreholes published study
A borehole sounds like a bit-of-a-stretch as a proxy. How could we tell if the world was warmer in 1066 by drilling a hole in the ground? Yes, fair point. But what makes boreholes useful is that they are global and there is a lot of data: specifically 6,000 holes all over the world.
I’ve been looking at boreholes in more detail, analyzing them in the light of newer proxies. When all the evidence is considered, boreholes turn out be not-much-use at giving us meaningful numbers in degrees C, and in my opinion, not-too-hot at telling us the “when” of an event either. Too much depends on assumptions.
But what are they good for is that, when combined with […]
Two major proxy studies, larger than ever, were released in April and June 2012. They show that the Medieval Warm Period (MWP) existed, and was similar to current temperatures. These comprehensive studies suggest current temperatures are not unusual, and that itself is not all that surprising — I’ve mentioned before how there are hundreds of proxy studies showing it was as warm or warmer back then. (CO2science has been documenting them.) But these studies are worth a mention because they are so large.
Climate models cannot explain what caused the warming 1000 years ago, nor the cooling 300 years ago, so they can’t rule out the same factors aren’t changing the climate today (though they claim they can). If climate models can’t explain the past, they can’t predict the future.
The last 12 Centuries
Ljungqvist used 120 proxy records — nearly 3 times as many proxies as previous studies and conclude: “during the 9th to 11th centuries there was widespread NH warmth comparable in both geographic extent and level to that of the 20th century”. Their proxies included ice-cores, pollen, marine sediments, lake sediments, tree-rings, speleothems and historical documentary data.
Ljungqvistet al 2012 Fig. 4. Mean time-series of centennial […]
A blockbuster Chinese study of Tibetan tree rings by Liu et al 2011 shows, with detail, that the modern era is a dog-standard normal climate when compared to the last 2,500 years. The temperature, the rate of change — it’s all been seen before. Nothing about the current period is “abnormal”, indeed the current warming period in Tibet can be produced through calculation of cycles. Liu et al do a Fourier analysis on the underlying cycles and do brave predictions as well.
In Tibet, it was about the same temperature on at least four occasions — back in late Roman times (those chariots!), then again in the dark ages (blame the collapse of industry), then in the middle ages (the Vikings?), then in modern times (blame the rise of industry).
Clearly, these climate cycles have nothing to with human civilization. Their team finds natural cycles of many different lengths are at work: 2-3 years, 100 years, 199 years, 800 years, and 1,324 years. The cold periods are associated with sunspot cycles. What we are not used to seeing are brave scientists willing to publish exact predictions of future temperatures for 100 years that include rises and falls. Apparently, it will […]
Fans of man-made global warming frequently tell us seas are rising, but somehow forget to mention the rise started 200 years ago, long before our coal-fired electricity plants cranked up, and long before anyone had an electric shaver, or a 6 cylinder fossil-fuel-spewing engine. Something else was driving that warming trend.
Here is the data from tide gauges going back 300 years from a paper by Jevrejeva et al 2008.
[Graphed by Joanne Nova based on data from Jevrejura et al located at this site PMSML]
This graph was calculated from 1023 tide gauge records [Jevrejeva et al., 2006] going back to 1850.The 2008 study extended the record further using three of the longest (though discontinuous) tide gauge records available: Amsterdam, since 1700 [Van Veen, 1945], Liverpool, since 1768 [Woodworth, 1999] and Stockholm, since 1774 [Ekman, 1988]. Obviously since there are only three old records, the error bars are a riot.
The Jevrejeva paper is also useful for portraying the 60 year rolling cycle. The regular ups and downs are obvious when the rate of change is plotted (see below).
7.5 out of 10 based on 20 ratings […]
Qassiarsuk: This is the site of the Viking settlement of 972 and unlike much of Greenland, offers relatively sheltered grazing land for sheep. Photo: John McLean. (Click to see more images of Greenland).
For the first time temperatures over the last 5,600 years have been reassembled from the inhabited area of Greenland. (Other estimates were from ice-cores that are far inland.)
William D’Andrea, the paper’s first author says: “.. we can say there is a definite cooling trend in the region right before the Norse disappear.”
8.2 out of 10 based on 5 ratings […]
A Scene on the Ice by Hendrick Avercamp, circa 1600
Dennis Avery reminds us of just how painfully cold the Little Ice Age was (see below) and also pointed me to this excellent historical description:
The Great Irish Frost of 1740, Longest Period of Extreme Cold in Modern European History
Biot Report #442:July 13, 2007
An extraordinary climatic shock—the Great Frost—struck Ireland and the rest of Europe between December 1739 and September 1741, after a decade of relatively mild winters. Its cause remains unknown. Charting its course sharply illuminates the connectivity between climate change and famine, epidemic disease, economies, energy sources, and politics. David Dickson, author of Arctic Ireland (1997) provides keen insights into each of these areas, which may have application to human behaviors during similar future climatic shocks. The crisis of 1740-1741 should not be confused with the equally devastating Great Potato Famine in Ireland of the 1840s.
Though no barometric or temperature readings for Ireland (population in 1740 of 2.4 million people) survive from the Great Frost, Englishmen were using the mercury thermometer invented 25 years earlier by the Dutch pioneer Fahrenheit. (1) Indoor values during January 1740 were as […]
The public might not understand the science, but they do understand cheating
Dr. David Evans
6 October 2010
[A series of articles reviewing the western climate establishment and the media. The first and second discussed air temperatures, the third discussed ocean temperatures, and the fourth discussed past temperatures.]
Click to download a pdf file containing the whole series
Notice How They Never Directly Compare Temperature With Human Emissions of CO2?
According to the man-made theory of global warming promoted by the western climate establishment, the recent global warming is due to human emissions of greenhouse gases, which are dominated by carbon dioxide (CO2).
So let’s compare the alleged cause (human emissions of CO2) with the alleged effect (temperature).
Human emissions of CO2 have been estimated from historical data for the period 1751 (before the industrial revolution) to 2007 for the major sources—coal, gas, and petroleum use, cement production, and gas flaring—by the Carbon Dioxide Information Analysis Center within the US Department of Energy. (The cumulative figures below extrapolate to 2010 using average annual emissions for the previous 14 years.)
8.2 out of 10 based on 16 ratings […]
The public might not understand the science, but they do understand cheating
Dr. David Evans
6 October 2010
[A series of articles reviewing the western climate establishment and the media. The first and second discussed air temperatures, the third discussed ocean temperatures.]
Click to download a pdf file containing the whole series
They Don’t Tell You: The Current Global Warming Trend is Over 300 Years Old
A Scene on the Ice by Hendrick Avercamp, circa 1600
Satellite data only goes back to 1979, and global land-thermometer records only go back to 1850. Before that we have to resort to “proxies”, which are various natural phenomena from which temperature can be deduced. As we go further back in time, the errors and uncertainties increase.
7.3 out of 10 based on 9 ratings […]
These maps and graphs make it clear just how brazenly unscientific the Hockey Stick is.
It’s clear that the world was warmer during medieval times. Marked on the map are study after study (all peer-reviewed) from all around the world with results of temperatures from the medieval time compared to today. These use ice cores, stalagmites, sediments, and isotopes. They agree with 6,144 boreholes around the world which found that temperatures were about 0.5°C warmer world wide.
8.3 out of 10 based on 38 ratings […]
Guest post by Dr David Evans PDF at sciencespeak.com
Now that ClimateGate has buried the fraudulent hockey stick for good, it is easy to prove that global warming is not man-made: just compare the timing of our carbon dioxide emissions with the timing of global warming.
Human Emissions of Carbon Dioxide
Emissions of carbon dioxide by humans are easy to estimate from our consumption of coal, oil, and natural gas, and production of cement:
Figure 1: Carbon emissions by humans. Source: Carbon Dioxide Information Analysis Center.
The vast bulk of human emissions occurred after 1945, during post-WWII industrialization. Half of all human consumption of fossil fuels and cement production has occurred since the mid 1970s.
7.8 out of 10 based on 38 ratings […]
A big news day. It appears Steve McIntyre (volunteer unpaid auditor of Big-Government-Science) has killed the Hockey Stick a second time…
The details are on the last three days of Steve McIntyre’s site Climate Audit, and summed up beautifully on Watts Up.
The sheer effrontery and gall appears to be breathtaking.
The Briffa temperature graphs have been widely cited as evidence by the IPCC, yet it appears they were based on a very carefully selected set of data, so select, that the shape of the graph would have been totally transformed if the rest of the data had been included.
Kieth Briffa used 12 samples to arrive at his version of the hockey stick and refused to provide his data for years. When McIntyre finally got hold of it, and looked at the 34 samples that Briffa left out of his graphs, a stark message was displayed. McIntyre describes it today as one of the most disquieting images he’s ever presented.
10 out of 10 based on 10 ratings […]
Click for a larger (powerpoint size) image
The world has not warmed since 2001.
10 out of 10 based on 2 ratings […]
Just as the great bull run that could have no end, ended, another unthinkably big bubble quivers. Technical indicators are quietly being tripped that suggest the bull run in global temperatures may be toying with a reversal. Could another large human institution dependent on complex models be headed for it’s ‘Lehman Bros’ moment? […]
This is a Guest Post by Dr David Evans
The big temperature picture. Graph and insight from Dr Syun Akasofu (2009 International Conference on Climate Change, New York, March 2009).
The global temperature has been rising at a steady trend rate of 0.5°C per century since the depths of the little ice age in the 1700s (when the Thames River would freeze over every winter; the last time it froze over was 1804). On top of the trend are oscillations that last about thirty years in each direction:
1882 – 1910 Cooling 1910 – 1944 Warming 1944 – 1975 Cooling 1975 – 2001 Warming
In 2009 we are where the green arrow points, with temperature leveling off. The pattern suggests that the world has entered a period of slight cooling until about 2030.
8.7 out of 10 based on 19 ratings […]
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JoNova A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).
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