Articles Tagged "Papers Challenging AGW"

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New paper finds Arctic temperatures were up to 3.8°C warmer ~3000 years ago
Monday, March 11th 2013, 1:31 PM EDT
Co2sceptic (Site Admin)
Image Attachment

Graph on left side shows reconstructed July temperatures were 1-2°C higher than modern from 2500-1100 years ago [during the Roman and Medieval warming periods], and up to 3.8°C higher than modern from 3700-2800 years ago [during Egyptian and Minoan warming periods]. Second graph from left shows similar changes in Greenland ice core data.

A paper published today in Quaternary Science Reviews reconstructs Arctic temperatures in Kamchatka, USSR over the past 4,500 years and finds the highest reconstructed temperatures were about 3.8°C warmer than modern temperatures. The authors find "the highest reconstructed temperature reaching 16.8 °C between 3700 and 2800 years before the present," about 3.8°C above "modern temperatures (∼13 °C)." In addition, the data shows temperatures between 2500 - 1100 [during the Medieval and Roman warming periods] were about 1-2°C above modern temperatures of ~13°C. The paper adds to many other peer-reviewed papers demonstrating that there is nothing unusual, unnatural, or unprecedented regarding modern Arctic temperatures.
Source Link: hockeyschtick.blogspot.co.uk
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New paper shows 99% of IPCC models exaggerate warming in central & southeastern US
Monday, March 4th 2013, 5:50 PM EST
Co2sceptic (Site Admin)
A paper published today in the Journal of Climate finds that the latest IPCC climate models are unable to reproduce the cooling observed in the southeastern and central portions of the US during the 20th century. According to the authors, "Some parts of the U.S., especially the southeastern and central portion, cooled by up to 2°C during the 20th century, " but that "only 19 out of 100 all-forcing historical [climate models] simulated negative temperature trends (cooling) over the southeast U.S. with 99 members under-predicting the cooling rate in the region."

The authors also find, "the simulations with greenhouse gases (GHG) forcing only produced strong warming in the central U.S." in comparison to the observed cooling. The paper adds to many other peer-reviewed papers demonstrating that climate models greatly exaggerate warming, and the alleged effects of increased greenhouse gases. It is also remarkable that the "adjusted" temperature record still shows the central & southeastern US cooled up to 2°C during the 20th century, despite massive data tampering to produce an artificial warming trend in US temperatures of > 1°C.

Abstract

Some parts of the U.S., especially the southeastern and central portion, cooled by up to 2°C during the 20th century, while the global mean temperature rose by 0.6 °C (0.76 °C from 1901-2006). Studies have suggested that the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) may be responsible for this cooling, termed “warming hole (WH)”, while other works reported that regional scale processes like the low-level jet and evapotranspiration contribute to the abnormality.
Source Link: hockeyschtick.blogspot.co.uk
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New paper finds natural variability controls CO2 levels, not man
Wednesday, February 6th 2013, 9:23 AM EST
Co2sceptic (Site Admin)
An important new paper published today in Global Biogeochemical Cycles finds that "In contrast to recent claims, trends in the airborne fraction of anthropogenic carbon [dioxide] cannot be detected when accounting for the decadal-scale influence of explosive volcanism and related uncertainties." In other words, after accounting for the large effect of volcanic eruptions, ENSO, and other uncertainties upon natural CO2 sinks, trends in the man-made fraction of atmospheric CO2 "cannot be detected." Thus, despite an exponential increase in man-made CO2 emissions, there is no statistically significant trend in the man-made fraction of CO2 in the atmosphere.

This further suggests that man is not the primary cause of the increase of CO2 in the atmosphere, that temperature is responsible for the increase in CO2 levels due to out-gassing. According to the authors, "Our results highlight the importance of considering the role of natural variability in the carbon cycle for interpretation of observations and for data-model intercomparison."

Note man-made emissions are only about 4% of the total CO2 emissions in the atmosphere, and CO2 only represents about 0.04% of the entire atmosphere


Click source to read more and link
Source Link: hockeyschtick.blogspot.co.uk
New Research Blows Climate Science Wide Open by Graham Lloyd
Saturday, February 2nd 2013, 2:30 PM EST
Co2sceptic (Site Admin)
THE world’s great forests have long been recognised as the lungs of the earth, but the science establishment has been rocked by claims that trees may also be the heart of its climate. Not only do trees fix carbon and produce oxygen; a new and controversial paper says they collectively unleash forces powerful enough to drive global wind patterns and are a core feature in the circulation of the climate system.

If the theory proves correct, the peer-reviewed international paper co-authored by Australian scientist Douglas Sheil will overturn two centuries of conventional wisdom about what makes wind. And it will undermine key principles of every model on which climate predictions are based.

The paper, Where do winds come from? A new theory on how water vapour condensation influences atmospheric pressure and dynamics, is not designed to challenge the orthodox view on climate science. But Sheil, a professor of forest ecology and conservation at Southern Cross University’s School of Environment, Science and Engineering, says he is not surprised that is how the paper has been received internationally.

Boiled down, he says, bad science is protecting shoddy climate models.

The paper, lead authored by Anastasia Makarieva, sparked a long-running and furious debate about whether it should be published at all. At the end of a bruising assessment process the editorial panel of the prestigious journal Atmospheric Chemistry and Physics chose to publish and be damned.

In an accompanying statement the journal editorial board said: “The paper is highly controversial, proposing a fundamentally new view that seems to be in contradiction to common textbook knowledge. The majority of reviewers and experts in the field seem to disagree, whereas some colleagues provide support, and the handling editor (and the executive committee) are not convinced that the new view presented in the controversial paper is wrong.
Source Link: theaustralian.com.au/national-affairs/climate
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Solar Activity At End Of 20th Century Was At Highest Levels Of Past 9,000 Years
Wednesday, January 23rd 2013, 8:04 AM EST
Co2sceptic (Site Admin)
Image Attachment

A 2012 paper published in the Proceedings of the National Academy of Sciences reconstructs solar activity from isotopes in ice cores and tree rings, and finds solar activity at the end of the 20th century was at the highest levels of the past 9,000 years.

The paper confirms other peer-reviewed publications indicating that the Sun was particularly active during the 20th century in comparison to the past several millenia In addition, the authors find good agreement between solar activity and the Asian climate as determined from stalagmites in the Dongge cave, China.

Blowup and flipped 1st graph (above) from Fig. 4 below shows the year 2000 at the right side of the graph, 9000 years ago at the left side. Added red line shows solar activity in blue at the end of the record was at the highest levels of the past 9000 years. Note graph has been reversed vertically since the graph below in Fig. 4 is on a reverse scale.
Source Link: hockeyschtick.blogspot.co.uk
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New paper finds solar cycle changes Earth temperature
Saturday, January 19th 2013, 11:53 AM EST
Co2sceptic (Site Admin)
Image AttachmentFig. 2. Variations of external factors: (top panel) solar activity (SSN) and the C9-index of geomagnetic activity (dimensionless index); (bottom panel) variations of DVIGlobal (dimensionless index) and the aerosol backscattering coefficients () at wavelength 694.3 nm. The solid vertical lines indicate the dates of intensive volcanic eruptions (Volcanic Explosive Index (VEI) ≥ 5.0) for 1880–1991.

A paper published today in the Journal of Atmospheric and Solar-Terrestrial Physics finds a significant influence of solar activity upon Earth temperature during the second half of the 20th century.

The authors find surface temperature linked to the 11-year solar cycle, and also influenced by the timing of volcanic eruptions. Once again, the claim by climate alarmists that small variations in solar activity cannot control temperature or climate has been debunked by observations.

Abstract

In this paper we analyze the geographical distribution of the climate response to external forcing (solar, volcanic and geomagnetic) on the periods of 11 and 22 years. As a climate characteristic we use the data of the air-surface temperature (regional data sets).
Source Link: hockeyschtick.blogspot.co.uk
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New paper confirms findings of Lindzen & Spencer of very low climate sensitivity to CO2
Tuesday, January 15th 2013, 12:46 PM EST
Co2sceptic (Site Admin)
A paper under review for Earth System Dynamics uses a novel technique based on satellite data and surface air temperatures to find that global warming due to increased CO2 is is much less than claimed by the IPCC. According to the author, the findings confirm those of Spencer & Braswell and Lindzen & Choi that a doubling of CO2 levels would only lead to an increase in top of the atmosphere temperature of 0.67°C, or global surface temperature of about 0.18°C, instead of the alleged 3°C claimed by IPCC computer models.

The observations indicate a climate feedback parameter of 5.5 Wm−2 K−1, which is in very close agreement to that found by Spencer and Braswell (2010) of 6 Wm−2 K−1, as well as that found by Lindzen and Choi (2011). A climate feedback parameter of 5.5 Wm−2 K−1 corresponds to global warming at the surface of only [1 Wm-2]/[5.5 Wm−2 K−1] = 0.18 °C per doubling of CO2 levels [or 3.7/5.5 = 0.67°C at the top of the atmosphere], far less than the 3°C global warming claimed by the IPCC.

From the paper:

"An unusually high value of the climate feedback parameter of 6 Wm−2 K−1 is suggested by the phase plane plots in Spencer and Braswell (2010). This corresponds to a very low climate sensitivity that disagrees with the majority of the other estimations of the climate sensitivity (Knutti and Hegerl, 2008; Randall et al., 2007; Huber et al., 2011). A discussion of the various methods for estimation of the climate sensitivity is beyond the scope of this work. Here we discuss a method for estimating the value of the climate feedback parameter from satellite radiative flux data and leave the question how to relate the result from this method to the equilibrium climate sensitivity to future work."
Source Link: hockeyschtick.blogspot.co.uk
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Solar Climate Change: New paper finds Pacific tropical cyclones coincided with solar activity
Monday, January 7th 2013, 4:47 PM EST
Co2sceptic (Site Admin)
A new paper published in the Journal of Climate examines landfalling tropical cyclones along the eastern Pacific coast between the 16th and 20th centuries and finds the most persistent cycle lasted ~ 12 years and coincided with the ~11-12 year solar cycle.

Image Attachment

Abstract

Numerous studies have been conducted to document long term trends in tropical cyclone (TC) activity. However, the eastern Pacific has not received as much attention as other basins. Here we attempt the identification of TC formation in the Mexican eastern Pacific ocean before 1950. Using bibliographical and historical file consultation, we constructed a catalog of events related to intense storms and possible TCs that made landfall in the Mexican Pacific coasts. Between 1536 and 1948 we found a total of 119 events related to TCs. Then, using the Saffir-Simpson scale and the climatology of the region as the criteria to evaluate each event, we found 85 TCs. Furthermore, we constructed a historical time series of TCs between 1701 and 2010. The spectral analysis showed periodicities of ~2.6, 4, 5, 12, 16, 39 and 105 years, that coincide with some large-scale climatic phenomena and also with solar activity. In particular, the ~12-year cycle is the most persistent periodicity in our study.


H/T hockeyschtick.blogspot.co.uk

Click source for FULL paper

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Source Link: journals.ametsoc.org
New paper shows no "hot spot" as predicted by climate models, invalidates AGW
Thursday, November 22nd 2012, 10:57 AM EST
Co2sceptic (Site Admin)
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A paper published today in Geophysical Research Letters shows the mythical "hot spot" in the upper troposphere predicted by climate models is indeed still missing. The paper shows little change in the upper tropospheric temperature measured by radiosondes and satellites from 1979-2011, while climate models instead predicted a significant increase over the same period.

The paper confirms others showing that the so-called "fingerprint" of man-made global does not exist and therefore the computer models are based upon incorrect assumptions.


Click source to read FULL report
Source Link: hockeyschtick.blogspot.co.uk
New paper finds the highest storm activity is associated with cold periods
Wednesday, November 14th 2012, 6:36 AM EST
Co2sceptic (Site Admin)
A new paper published in Nature Geoscience examines climate change over the past 11,500 years and finds, contrary to the claims of climate alarmists, that the highest storm activity is associated with cold periods.

According to the authors, "We find that high storm activity occurred periodically with a frequency of about 1,500 years, closely related to cold and windy periods." The paper adds to several others showing that global warming decreases storm activity and extreme weather.

Persistent non-solar forcing of Holocene storm dynamics in coastal sedimentary archives - by Philippe Sorrel, Maxime Debret, Isabelle Billeaud, Samuel L. Jaccard, Jerry F. McManus & Bernadette Tessier

Considerable climatic variability on decadal to millennial timescales has been documented for the past 11,500 years of interglacial climate1, 2, 3.

This variability has been particularly pronounced at a frequency of about 1,500 years, with repeated cold intervals in the North Atlantic1, 3. However, there is growing evidence that these oscillations originate from a cluster of different spectral signatures4, ranging from a 2,500-year cycle throughout the period to a 1,000-year cycle during the earliest millennia.
Source Link: hockeyschtick.blogspot.co.uk
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