Empirical evidence = changing Attitudes

Greenland cold snap linked to Viking disappearance

Posted 2011/05/30 at 4:37 pm EDT
OSLO, May 30, 2011 (Reuters) — A cold snap in Greenland in the 12th century may help explain why Viking settlers vanished from the island, scientists said on Monday
The report, reconstructing temperatures by examining lake sediment cores in west Greenland dating back 5,600 years, also indicated that earlier, pre-historic settlers also had to contend with vicious swings in climate on icy Greenland.
"Climate played (a) big role in Vikings' disappearance from Greenland," Brown University in the United States said in a statement of a finding that average temperatures plunged 4 degrees Celsius (7F) in 80 years from about 1100.
Such a shift is roughly the equivalent of the current average temperatures in Edinburgh, Scotland, tumbling to match those in Reykjavik, Iceland. It would be a huge setback to crop and livestock production.
"There is a definite cooling trend in the region right before the Norse disappear," said William D'Andrea of Brown University, the lead author of the study in the U.S. journal Proceedings of the National Academy of Sciences.
Researchers have scant written or archaeological records to figure out why Viking settlers abandoned colonies on the western side of the island in the mid-1300s and the eastern side in the early 1400s.
Conflicts with indigenous Inuit, a search for better hunting grounds, economic stresses and natural swings in climate, perhaps caused by shifts in the sun's output or volcanic eruptions, could all be factors.
LITTLE ICE AGE
Scientists have previously suspected that a cooling toward a "Little Ice Age" from the 1400s gradually shortened growing seasons and added to sea ice that hampered sailing links with Iceland or the Nordic nations.
The study, by scientists in the United States and Britain, added the previously unknown 12th century temperature plunge as a possible trigger for the colonies' demise. Vikings arrived in Greenland in the 980s, during a warm period like the present.
"You have an interval when the summers are long and balmy and you build up the size of your farm, and then suddenly year after year, you go into this cooling trend, and the summers are getting shorter and colder and you can't make as much hay," D'Andrea said.
The study also traced even earlier swings in the climate to the rise and fall of pre-historic peoples on Greenland starting with the Saqqaq culture, which thrived from about 4,500 years ago to 2,800 years ago.
Scientists fear that the 21st century warming is caused by climate change, stoked by a build-up of greenhouse gases from human activities. An acceleration of warming could cause a meltdown of the Greenland ice sheet, raising world sea levels
http://www.newsdaily.com/stories/tre74t529-us-cli mate-greenland/

Now read the press release from Brown University

Climate helped drive Vikings from Greenland
May 30, 2011 | Contact: Richard Lewis | 401-863-3766


Greenland's early Viking settlers were subjected to rapidly changing climate. Temperatures plunged several degrees in a span of decades, according to research from Brown University. A reconstruction of 5,600 years of climate history from lakes near the Norse settlement in western Greenland also shows how climate affected the Dorset and Saqqaq cultures. Results appear in Proceedings of the National Academy of Sciences.

PROVIDENCE, R.I. [Brown University] — The end of the Norse settlements on Greenland likely will remain shrouded in mystery. While there is scant written evidence of the colony’s demise in the 14th and early 15th centuries, archaeological remains can fill some of the blanks, but not all.

What climate scientists have been able to ascertain is that an extended cold snap, called the Little Ice Age, gripped Greenland beginning in the 1400s. This has been cited as a major cause of the Norse’s disappearance. Now researchers led by Brown University show the climate turned colder in an earlier span of several decades, setting in motion the end of the Greenland Norse. Their findings appear in Proceedings of the National Academy of Sciences.

The Brown scientists’ finding comes from the first reconstruction of 5,600 years of climate history from two lakes in Kangerlussuaq, near the Norse “Western Settlement.” Unlike ice cores taken from the Greenland ice sheet hundreds of miles inland, the new lake core measurements reflect air temperatures where the Vikings lived, as well as those experienced by the Saqqaq and the Dorset, Stone Age cultures that preceded them.

“This is the first quantitative temperature record from the area they were living in,” said William D’Andrea, the paper’s first author, who earned his doctorate in geological sciences at Brown and is now a postdoctoral researcher at the University of Massachusetts–Amherst. “So we can say there is a definite cooling trend in the region right before the Norse disappear.”

“The record shows how quickly temperature changed in the region and by how much,” said co-author Yongsong Huang, professor of geological sciences at Brown, principal investigator of the NSF-funded project, and D’Andrea’s Ph.D. adviser. “It is interesting to consider how rapid climate change may have impacted past societies, particularly in light of the rapid changes taking place today.”

D’Andrea points out that climate is not the only factor in the demise of the Norse Western Settlement. The Vikings’ sedentary lifestyle, reliance on agriculture and livestock for food, dependence on trade with Scandinavia and combative relations with the neighboring Inuit, are believed to be contributing factors.

Still, it appears that climate played a significant role. The Vikings arrived in Greenland in the 980s, establishing a string of small communities along Greenland’s west coast. (Another grouping of communities, called the “Eastern Settlement” also was located on the west coast but farther south on the island.) The arrival coincided with a time of relatively mild weather, similar to that in Greenland today. However, beginning around 1100, the climate began an 80-year period in which temperatures dropped 4 degrees Celsius (7 degrees Fahrenheit), the Brown scientists concluded from the lake readings. While that may not be considered precipitous, especially in the summer, the change could have ushered in a number of hazards, including shorter crop-growing seasons, less available food for livestock and more sea ice that may have blocked trade.

“You have an interval when the summers are long and balmy and you build up the size of your farm, and then suddenly year after year, you go into this cooling trend, and the summers are getting shorter and colder and you can’t make as much hay. You can imagine how that particular lifestyle may not be able to make it,” D’Andrea said.

Archaeological and written records show the Western Settlement persisted until sometime around the mid-1300s. The Eastern Settlement is believed to have vanished in the first two decades of the 1400s.

The researchers also examined how climate affected the Saqqaq and Dorset peoples. The Saqqaq arrived in Greenland around 2500 B.C. While there were warm and cold swings in temperature for centuries after their arrival, the climate took a turn for the bitter beginning roughly 850 B.C., the scientists found. “There is a major climate shift at this time,” D’Andrea said. “It seems that it’s not as much the speed of the cooling as the amplitude of the cooling. It gets much colder.”

The Saqqaq exit coincides with the arrival of the Dorset people, who were more accustomed to hunting from the sea ice that would have accumulated with the colder climate at the time. Yet by around 50 B.C., the Dorset culture was waning in western Greenland, despite its affinity for cold weather. “It is possible that it got so cold they left, but there has to be more to it than that,” D’Andrea said.

Contributing authors include Sherilyn Fritz from the University of Nebraska–Lincoln and N. John Anderson from Loughborough University in the United Kingdom. The National Science Foundation funded the work.

http://news.brown.edu/pressreleases/2011/05/vikin gs

No where is to be found:

Scientists fear that the 21st century warming is caused by climate change, stoked by a build-up of greenhouse gases from human activities.

So who added the the last statement from the first article from Reuters? The news agency? The reporter? It certainly was not from the official press release!!!!
No credible scientist would assert such when pre - AGW data indicates repeated 4 degrees Celsius shifts in short time frames.
Here in lies the problem.
Who would not be sceptical provided with such misinformation?

The announcement made on 14 June (18:00 UK time) comes from scientists at the US National Solar Observatory (NSO) and US Air Force Research Laboratory. Three different analyses of the Sun's recent behaviour all indicate that a period of unusually low solar activity may be about to begin.

The Sun normally follows an 11-year cycle of activity. The current cycle, Cycle 24, is now supposed to be ramping up towards maximum strength. Increased numbers of sunspots and other indications ought to be happening: but in fact results so far are most disappointing. Scientists at the NSO now suspect, based on data showing decades-long trends leading to this point, that Cycle 25 may not happen at all.

This could have major implications for the Earth's climate. According to a statement issued by the NSO, announcing the research:

An immediate question is whether this slowdown presages a second Maunder Minimum, a 70-year period with virtually no sunspots [which occurred] during 1645-1715.


Link

http://solarscience.msfc.nasa.gov/predict.shtml


The current prediction for Sunspot Cycle 24 gives a smoothed sunspot number maximum of about 69 in June of 2013. We are currently over two and a half years into Cycle 24. Three consecutive months with average daily sunspot numbers above 40 has raised the predicted maximum above the 64.2 for the Cycle 14 maximum in 1907. The predicted size would make this the smallest sunspot cycle in over 100 years.
Predicting the behavior of a sunspot cycle is fairly reliable once the cycle is well underway (about 3 years after the minimum in sunspot number occurs [see Hathaway, Wilson, and Reichmann Solar Physics; 151, 177 (1994)]). Prior to that time the predictions are less reliable but nonetheless equally as important. Planning for satellite orbits and space missions often require knowledge of solar activity levels years in advance.


http://solarscience.msfc.nasa.gov/images/ssn_pred ict.gif


Many things can change temperatures on Earth: a volcano erupts, swathing the Earth with bright haze that blocks sunlight, and temperatures drop; greenhouse gases trap heat in the atmosphere, and temperatures climb. From 1650 to 1710, temperatures across much of the Northern Hemisphere plunged when the Sun entered a quiet phase now called the Maunder Minimum. During this period, very few sunspots appeared on the surface of the Sun, and the overall brightness of the Sun decreased slightly. Already in the midst of a colder-than-average period called the Little Ice Age, Europe and North America went into a deep freeze: alpine glaciers extended over valley farmland; sea ice crept south from the Arctic; and the famous canals in the Netherlands froze regularly—an event that is rare today.
The impact of the solar minimum is clear in this image, which shows the temperature difference between 1680, a year at the center of the Maunder Minimum, and 1780, a year of normal solar activity, as calculated by a general circulation model. Deep blue across eastern and central North America and northern Eurasia illustrates where the drop in temperature was the greatest. Nearly all other land areas were also cooler in 1680, as indicated by the varying shades of blue. The few regions that appear to have been warmer in 1680 are Alaska and the eastern Pacific Ocean (left), the North Atlantic Ocean south of Greenland (left of center), and north of Iceland (top center).
If energy from the Sun decreased only slightly, why did temperatures drop so severely in the Northern Hemisphere? Climate scientist Drew Shindell and colleagues at the NASA Goddard Institute for Space Studies tackled that question by combining temperature records gleaned from tree rings, ice cores, corals, and the few measurements recorded in the historical record, with an advanced computer model of the Earth’s climate. The group first calculated the amount of energy coming from the Sun during the Maunder Minimum and entered the information into a general circulation model. The model is a mathematical representation of the way various Earth systems—ocean surface temperatures, different layers of the atmosphere, energy reflected and absorbed from land, and so forth—interact to produce the climate.
When the model started with the decreased solar energy and returned temperatures that matched the paleoclimate record, Shindell and his colleagues knew that the model was showing how the Maunder Minimum could have caused the extreme drop in temperatures. The model showed that the drop in temperature was related to ozone in the stratosphere, the layer of the atmosphere that is between 10 and 50 kilometers from the Earth’s surface. Ozone is created when high-energy ultraviolet light from the Sun interacts with oxygen. During the Maunder Minimum, the Sun emitted less strong ultraviolet light, and so less ozone formed. The decrease in ozone affected planetary waves, the giant wiggles in the jet stream that we are used to seeing on television weather reports.
http://earthobservatory.nasa.gov/IOTD/view.php?id =7122

38.
At 17:13 18th Jun 2011, QuaesoVeritas wrote:

For anyone interested, the Newsnight programme on the sun is still available on iPlayer, although only until the 23rd., from this location:
http://www.bbc.co.uk/iplayer/episode/b0120y31/New snight_16_06_2011/
Firstly I thought it was interesting that the BBC Science Editor, Susan Watts stated as fact that the more sunspots you have, the warmer the planet is, and the fewer you have, the cooler it is, and I don't think it is as clear cut as that.
Also, Dr Lucie Green, stated that the sun was unusually quiet and that it would continue to get quieter, which again I don't think is the case. As far as I am concerned, the Sun, based on sunspot numbers, is just at the beginning of cycle 24, i.e. at month 21 of a possible 132 months, and will not reach it's maximum until around 2013, so I don't know how anyone can currently say that it's going to get quieter from now on.
She actually said that from now on, "the sunspot number will drop and drop", but I can only see it rising for the next 2 years.
Watts went on to say that any effects of a "quiet sun" woudn't be sufficient to offset the effects of CO2 emissions, obviously blissfully unaware that temperatures have actually been falling by some measures over the last 10 years and that most of the model projections in the various IPCC models were excessive, even most of those in the "commitment" scenario, which assumes zero growth in greenhouse gasses.
I was also surprised that Ken Caldeira said that if the emissions from the volcanic eruption in 1991 had stayed in the stratosphere, that would have been enough to offset all of the expected warming over the next century, since the global HadCRUT3 anomaly only fell by 0.14c between 1991 and 1992. Clearly he was using one of the lower estimates of future warming.
But most of the programme seemed to be a discussion of the merits of geoengineering solutions, not about the likely effects of a "quiet sun".
God help us if some of those suggestions ever get off the drawing board, since they will probably make matters worse.


Some can see the bias for what it is.

Attack Of The Snowflakes Haiku




There is nothing like

being pelted by Heaven's

dizzy frozen tears


I wish Heaven would

quit crying so that Spring would

finally get here


White spirals downpour

Winter's avenging ninjas

disappear from sight


Wrong season snowfall

shouldn't happen at this time

Nature's ten foot mess


How can such tiny

feather light flakes reach such high

accumulation?


Was Heaven angry

when our planet rocked and rolled

wrapped like a snowball


Glacial planet

shaking to the music of

the sphere's legacy


What a cold promise

when the weather teases me

longing a Spring sign


I've come to realise

Winter, the mini-ice age

is Earth's sleepy time


I'm stuck shoveling

a ton of snowy cold ice

caused by climate change


I could really use

that global warming just send

it posthaste my way.


Create Date : Monday, March 09, 2009
Update Date : Wednesday, March 11, 2009

Lorraine Margueritte Gasrel Black




Nice poem.