Study of Old Climate Records Shows That Baghdad Was Quite Chilly a Millennium Ago

Re-blogged from Popular Science    Article written by Rebecca Boyle

An unexpected cold wave in July 920 sent the people of Baghdad back under their blankets, forcing them to leave their summertime roof beds and go back inside, according to a new study by Spanish researchers. The temperature dropped about 16 degrees F compared to average July temperatures, the study found. That was in 920; there’s no “1” in there.

Arabic historians’ records chronicle life in Baghdad in the Middle Ages, and some of the reports mention the area’s climate. Now scientists have interpreted them for the first time, and found some surprising meteorological events in the areas now known as Iraq and Syria. It used to snow more often, with at least six snowfalls between 902 and 944. (There has been only one snowfall in Baghdad in modern times, on Jan. 11, 2008.) The Arabic historians also recounted droughts, floods, heavy rains and frost, not a common occurrence in the fertile crescent.

The researchers, led by Fernando Domínguez-Castro in the physics department at the University of Extremadura, believe a couple volcanic eruptions in central America could have been to blame for the July 920 cold snap. During some of those nights, temperatures never rose above 64 degrees F — pretty cool for a Baghdad July.

The Guagua Pichincha volcano in Ecuador erupted around 910, and the Ceboruco volcano in Mexico erupted around 930. Eruptions like that have been shown to affect global temperatures. But more evidence is needed to confirm this hypothesis, Domínguez-Castro said.

This is interesting in part because this is a time and a place about which very little is known, the researchers say. But along with their historical significance, these records could help scientists’ understanding of future climates. Knowledge of past trends and abnormalities improves climate models, for instance. Time and again we have seen how old records can paint a fuller picture of our modern lives — in this case, by looking at in the Middle East in the years before the first crusades. The research appears in the journal Weather.

Note,  this record took place at the end of a known cold period before the beginning of the Medieval Warming Period. It should have been cooler over a longer period, before this reported incident of a cold July. 


On the Cusp of the Next Grand Minimum?

Russ Steele

Last week at a fund raising dinner I sat next to the owner of a local vineyard who explained why a shortage exists in one of his signature wines. It was due to two cold springs in a row, then followed up by a cool summer in 2011. Spring freezes in April and May killed some of his vines. The cool summer slowed the growth of sugar in the surviving grapes.

Now we learn up to 100% of this years apple crop in New York state have been destroyed by a late spring hard freeze.


APR 29 2012




TV Interviews this morning with New York apple orchard owner indicated they have lost 100% of their crop.

These are stand alone events, but maybe early indicators of what is ahead.  The first indicators we are on the cusp of the next grand minimum will be shortening of the growing season, late spring frosts and early fall freezes.  We will be on the lookout for June killing frosts in America’s bread basket. Stay Tuned.

Did exploding stars help life on Earth to thrive?

Russ Steele

Today the Royal Astronomical Society in London publishes Henrik Svensmark’s latest paper entitled “Evidence of nearby supernovae affecting life on Earth”. After years of effort Svensmark shows how the variable frequency of stellar explosions not far from our planet has ruled over the changing fortunes of living things throughout the past half billion years.

Below is Royal Astronomical Society Press Release

Research by a Danish physicist suggests that the explosion of massive stars – supernovae – near the Solar System has strongly influenced the development of life. Prof. Henrik Svensmark of the Technical University of Denmark (DTU) sets out his novel work in a paper in the journal Monthly Notices of the Royal Astronomical Society.

When the most massive stars exhaust their available fuel and reach the end of their lives, they explode as supernovae, tremendously powerful explosions that are briefly brighter than an entire galaxy of normal stars. The remnants of these dramatic events also release vast numbers of high-energy charged particles known as galactic cosmic rays (GCR). If a supernova is close enough to the Solar System, the enhanced GCR levels can have a direct impact on the atmosphere of the Earth.

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Sun may soon have four poles, say researchers

Russ Steele

This is very interesting and I will be looking for other scientist to report their analysis of this findings. First time I ever hear of a four pole sun, though it could have happend before, but scientists lacked the tools and were not watching during the 17th Century. My emphasis added.

By SEIJI TANAKA/ Staff Writer

The sun may be entering a period of reduced activity that could result in lower temperatures on Earth, according to Japanese researchers.

Officials of the National Astronomical Observatory of Japan and the Riken research foundation said on April 19 that the activity of sunspots appeared to resemble a 70-year period in the 17th century in which London’s Thames froze over and cherry blossoms bloomed later than usual in Kyoto.

In that era, known as the Maunder Minimum, temperatures are estimated to have been about 2.5 degrees lower than in the second half of the 20th century.

The Japanese study found that the trend of current sunspot activity is similar to records from that period.

The researchers also found signs of unusual magnetic changes in the sun. Normally, the sun’s magnetic field flips about once every 11 years. In 2001, the sun’s magnetic north pole, which was in the northern hemisphere, flipped to the south.

While scientists had predicted that the next flip would begin from May 2013, the solar observation satellite Hinode found that the north pole of the sun had started flipping about a year earlier than expected. There was no noticeable change in the south pole.

If that trend continues, the north pole could complete its flip in May 2012 but create a four-pole magnetic structure in the sun, with two new poles created in the vicinity of the equator of our closest star.

via Sun may soon have four poles, say researchers – AJW by The Asahi Shimbun.

Robust Agriculture Sector Will Be Key to Survival During Next Grand Minimum

Russ Steele

As a conservative I have taken a very negative view of subsides for green energy, renewable energy, especially ethanol which consumes food for fuel.  I recently participated in a discussion of agriculture subsides and came to the realization that some agricultural subsides may have future survival benefits and may even have an impact on our national security.

As many readers of  this blog know, I have been examining the possibility of another Grand Minimum for some time, presenting studies and scientific evidence to support my position and for reader evaluation and comment.  There is growing evidence that a Grand Minimum similar to the Maunder is in our future, see references herehere, here, here and here.

One of the agricultural impacts of a Maunder scale minimum is long term drought. See my post on the Maunder Minimum and Fall of Ming Dynasty . Anther impact is shortening the length of the growing season, shifting regions of production farther south.

In 1980 Newman (see references) published a paper showing that the Corn Belt shifted 144 km per 1.0°C change in temperature. If the temperature were to all fall 5.2°C, the Corn Belt would shift 750 km south to the Sun Belt, as shown following graphic provided by David Archibald:

The outlook for Canadian agriculture is somewhat more dire, as wheat growing regions shift south into the the United States. (David Archibald)

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New Physics Today Article “The Triggering And Persistence Of The Little Ice Age” (Update)

This is a re-post from Climate Science: Roger Pielke Sr. Blog

Dr Pielke writes: Every once in a while a nugget of new research insight appears that adds to our understanding of the climate system, and its complexity. One article of this type has appeared.

Miller, G. H., et al. (2012), Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks, Geophys. Res. Lett.,39,L02708,doi:10.1029/2011GL050168


Northern Hemisphere summer temperatures over the past 8000 years have been paced by the slow decrease in summer insolation resulting from the precession of the equinoxes. However, the causes of superposed century-scale cold summer anomalies, of which the Little Ice Age (LIA) is the most extreme, remain debated, largely because the natural forcings are either weak or,in the case of volcanism, short lived. Here we present precisely dated records of ice-cap growth from Arctic Canada and Iceland showing that LIA summer cold and ice growth began abruptly between 1275 and 1300 AD, followed by a substantial intensification 1430–1455 AD. Intervals of sudden ice growth coincide with two of the most volcanically perturbed half centuries of the past millennium. A transient climate model simulation shows that explosive volcanism produces abrupt summer cooling at these times, and that cold summers can be maintained by sea-ice/ocean feedbacks long after volcanic aerosols are removed. Our results suggest that the onset of the LIA can be linked to an unusual 50-year-long episode with four large sulfur-rich explosive eruptions,each with global sulfate loading >60 Tg. The persistence of cold summers is best explained by consequent sea-ice/ocean feedbacks during a hemispheric summer insolation minimum; large changes in solar irradiance are not required.

The Key Points listed in the Miller et al 2012 paper are:

  • Little Ice Age began abruptly in two steps
  • Decadally paced explosive volcanism can explain the onset
  • A sea-ice/ocean feedback can sustain the abrupt cooling

The Miller et al article is summarized HERE.

I have added the following graphic for a visual reference to the cooling and the eruptions:

Update (04-13-12: 11:00) I was look at the above graphic and I could see cold happening before the volcano eruptions, leading me to wonder if the above article has all the facts right. So did Willis Eschenbach in Guest Post at Watts Up With ThatDronning Maud Meets the Little Ice Age.  Willis concludes: 

I’m sorry, but I just don’t see the evidence that volcanoes had anything to do with the changes in the Baffin Island ice cap. And their whole sea/ice feedback claim? I note that the claim is supported by … well … I fear all it is supported by is models all the way down.

I recommend that you read the full post by Willis. As you can see on the graphic, there were volcano eruptions while warming was taking place, leading one to believe the volcano connection to starting the LIA are suspect. Now one could make the case they deepened the cold and misery for a few years, but not for long periods as proposed in the article. Stay Tuned, there will be more analysis to come.

Little Ice Age Was The Coldest Period For 10000 Years

Russ Steele

Paul Homewood, had an interesting post at: Little Ice Age Was The Coldest Period For 10000 Years

We regularly hear claims of “record breaking” and “unprecedented” temperatures in Arctic regions. However, as the records usually only go back to the 19th C, these statements are pretty meaningless.

There are in fact many scientific studies that show the Little Ice Age, which came to end in the late 19th C, was the coldest period in these regions for maybe 10000 years.

We have already seen studies by Jorgen Peder Steffensen (based on ice cores) and Ribeiro et al (dinoflagellates), which both come to the same conclusion. Let’s take a look at four more.

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Are We On the Cusp of Global Cooling and Growing Ice

Russ Steele

Sea Ice melting has been delayed by Mother Nature in 2012.

As you can see from the graphic sea ice melting has been delayed by at least a month in both 2010, to a lesser degree in 2011 and certainly in 2012.

According to the National Snow and Ice Data Center (NSICD), “ice cover remained extensive in the Bering Sea, where it has been above average all winter. “

“Ice extent was also higher than average in Baffin Bay, between Greenland and Canada, and the Sea of Okhotsk, north of Russia.”

“Air temperatures were 6 to 8 degrees Celsius (11 to 14 degrees Fahrenheit) below average over the Bering Sea, Baffin Bay, and parts of the Sea of Okhotsk.”

“Overall, the Arctic gained 140,000 square kilometers (54,000 square miles) of ice during March. Typically, March has been a month of net ice loss (an average of 260,000 square kilometers [100,000 square miles] for 1979 to 2000), but the last three Marches have had net ice growth.”

Annual ice growing is how ice ages get started.  We need to see how much ice melts this summer and the ice growth in the winter of 2013. Stay Tuned!

H/T to Ice Age Now.

THE HOCKEY SCHTICK: New paper finds significant, natural decrease in cloudiness over past 50 years

Re-blogged from The Hockey Schtick

New paper finds significant, natural decrease in cloudiness over past 50 years

A paper published last week finds that cloud cover over China significantly decreased during the period 1954-2005. This finding is in direct contradiction to the theory of man-made global warming which presumes that warming allegedly from CO2 should cause an increase in water vapor and cloudiness. The authors also find the decrease in cloud cover was not related to man-made aerosols, and thus was likely a natural phenomenon, potentially a result of increased solar activity via the Svensmark theory or other mechanisms. As climatologist Dr. Roy Spencer has pointed out his book,

 “The most obvious way for warming to be caused naturally is for small, natural fluctuations in the circulation patterns of the atmosphere and ocean to result in a 1% or 2% decrease in global cloud cover. Clouds are the Earth’s sunshade, and if cloud cover changes for any reason, you have global warming — or global cooling.”

Significant decreasing cloud cover during 1954–2005 due to more clear-sky days and less overcast days in China and its relation to aerosol

X. XiaLAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China

Abstract. An updated analysis of cloud cover during 1954–2005 in China was performed using homogeneous cloud cover data from 314 stations. Long-term changes in frequencies of different cloud cover categories and their contributions to long-term changes in cloud cover were assessed. Furthermore, aerosol effects on cloud cover trends were discussed based on comparison of cloud cover trends in polluted and mildly polluted regions. Frequencies of clear sky cloud cover80% were observed to increase by ~2.2 days and decrease by ~3.3 days per decade, respectively, which accounts for ~80% of cloud cover reduction. Larger decreasing trends in cloud cover due to larger increase in clear sky frequency and larger decreases in overcast frequency were observed at stations with lower aerosol optical depth. There is no significant difference in trends regarding cloud cover, clear sky frequency, and overcast frequency between mountain and plain stations. These results are inconsistent with our expectation that larger decreasing trends in cloud cover should have been observed in regions with higher aerosol loading where more aerosols could lead to stronger obscuring effect on ground observation of cloud cover and stronger radiative effect as compared with the mildly polluted regions. Aerosol effect on decreasing cloud cover in China appear not to be supported by this analysis and therefore, further study on this issue is required.

via THE HOCKEY SCHTICK: New paper finds significant, natural decrease in cloudiness over past 50 years.