Posted on 02/27/2006 10:53:31 AM PST by blam
Europe's chill linked to disease
By Kate Ravilious
Bubonic plague may have wiped out over a third of Europe's population
Europe's "Little Ice Age" may have been triggered by the 14th Century Black Death plague, according to a new study.
Pollen and leaf data support the idea that millions of trees sprang up on abandoned farmland, soaking up carbon dioxide from the atmosphere.
This would have had the effect of cooling the climate, a team from Utrecht University, Netherlands, says.
The Little Ice Age was a period of some 300 years when Europe experienced a dip in average temperatures.
Dr Thomas van Hoof and his colleagues studied pollen grains and leaf remains collected from lake-bed sediments in the southeast Netherlands.
Monitoring the ups and downs in abundance of cereal pollen (like buckwheat) and tree pollen (like birch and oak) enabled them to estimate changes in land-use between AD 1000 and 1500.
Pore clues
The team found an increase in cereal pollen from 1200 onwards (reflecting agricultural expansion), followed by a sudden dive around 1347, linked to the agricultural crisis caused by the arrival of the Black Death, most probably a bacterial disease spread by rat fleas.
This bubonic plague is said to have wiped out over a third of Europe's population.
Counting stomata (pores) on ancient oak leaves provided van Hoof's team with a measure of the fluctuations in atmospheric carbon dioxide for the same period.
This is because leaves absorb carbon dioxide through their stomata, and their density varies as carbon dioxide goes up and down.
"Between AD 1200 to 1300, we see a decrease in stomata and a sharp rise in atmospheric carbon dioxide, due to deforestation we think," says Dr van Hoof, whose findings are published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.
But after AD 1350, the team found the pattern reversed, suggesting that atmospheric carbon dioxide fell, perhaps due to reforestation following the plague.
The researchers think that this drop in carbon dioxide levels could help to explain a cooling in the climate over the following centuries.
Ocean damper
From around 1500, Europe appears to have been gripped by a chill lasting some 300 years.
There are many theories as to what caused these bitter years, but popular ideas include a decrease in solar activity, an increase in volcanic activity or a change in ocean circulation.
The new data adds weight to the theory that the Black Death could have played a pivotal role.
Not everyone is convinced, however. Dr Tim Lenton, an environmental scientist from the University of East Anglia, UK, said: "It is a nice study and the carbon dioxide changes could certainly be a contributory factor, but I think they are too modest to explain all the climate change seen."
And Professor Richard Houghton, a climate expert from Woods Hole Research Center in Massachusetts, US, believes that the oceans would have compensated for the change.
"The atmosphere is in equilibrium with the ocean and this tends to dampen or offset small changes in terrestrial carbon uptake," he explained.
Nonetheless, the new findings are likely to cause a stir.
"It appears that the human impact on the environment started much earlier than the industrial revolution," said Dr van Hoof.
He was here at least 3,000 years before the Indians.
You also have to figure this: There are still sharks swimming the slave trade routes across the atlantic because they were fed on the bodies of the noble african-americans that were thrown over after dying from the horrific conditions imposed by the MAN. These sharks would have reproduced at much higher rates, causing an overpopulation of sharks, which would have reduced the number of fish, which woould have made the oceans cooler.
I don't know... I think science is getting to scientific for me. I think I'll do a study that links poor bad mitton players with global warming and have it published. I could use the bucks.
I thought the thing about the great fire was that people built with brick instead of wood after that, and for some reason that helped with the rodent population.
I'd like to know the name of the book too.
I've read recently that some are beginning to think there were two different diseases involved in the Black Death.
I am sure they adjusted for this:
"The new method of paleoelevation involves counting the stomata on leaves of plants going back as far as 65 million years ago. Stomata are minute openings on the surface of leaves through which plants absorb gases, including carbon dioxide, which plants need for photosynthesis. Anyone who has climbed a mountain knows that the air gets "thinner" as you climb higher. As with oxygen, carbon dioxide is less concentrated at higher elevations. Therefore, the higher the elevation, the more stomata per square inch of leaf surface a plant would need to survive. By simply counting the number of fossil stomata, Dr. McElwain can estimate how much carbon dioxide was in the air when the fossil leaf developed. From that, she can estimate the elevation at which the fossil plant once lived.
Dr. McElwain used historical and modern collections of California Black Oak (Quercus kelloggii) leaves for her study because the California Black Oak grows at an unusually wide range of elevations from 200 to 8,000 feet (60 to 2,440 meters). The historical leaves were collected by botanists in the 1930s and stored within herbarium collections of the Field Museum and the University of California, Berkeley."
"Wouldn't most Europeans be descendents of survivors of the Plague? My family goes back to England."
If you're referencing the genetic mutation that confers some resistance or even immunity to the AIDS virus, this mutation is present in approximately 10% of individuals having northern European ancestry. Both of your parents would need to have the mutation, and pass it on to you, in order to have immunity. The mutation itself is believed to have arisen as a result of ancestral exposure to bubonic plague.
I think that burning down all the old pestholes between the Tower and the Fleet . . . basically the entire old medieval city within walls . . . including all the old thatch-and-pitch buildings, was what did the trick. The rats burned right along with the buildings, which was also a good thing.
But King Charles's decree that everything would be rebuilt in brick and stone didn't hurt.
It started here.
It ended here.
"There are still sharks swimming the slave trade routes across the atlantic because they were fed on the bodies of the noble african-americans that were thrown over after dying from the horrific conditions imposed by the MAN."
You're being satirical, but I've known a few people who actually believed this to be true.
Well, there had to be some overlap, so that he could teach the Ind...er, Native Americans...to smoke.
Not analytical enough.
The reduced number of fish would have reduced the amount of fish poop in the water. Algae feeds on fish poop, so there was less algae. Algae also warms up the water, so the reduced number of fish reduced the algae, which cooled down the water, and thereby potentially caused the climate to cool.
This was partially offset, of course, by all the smoking going on in Europe, and so the world was in equilibrium.
However, with the end of the slave trade, the sharks decreased, and fish increased, which meant more fish poop and great algal blooms.
Therefore, to stop global warming, we need to reinstate the slave trade. QED.
Revising hypotheses in the light of new information is a solid part of the scientific method.
As opposed to science, we have the {poof} theory. There are hundreds of claims as to who does the {poof}, so obviously they can not all be correct.
Faith has never removed any mountain, but good engineering makes tunnels.
Good call. I wonder how many know what lies behind that rhyme.
A gross understatement to say the least. The global warming wackos insist that CO2 is the main driving force to the climate, but the 4.5 billion year history of the earth does not bear that out. CO2 is a minor player.
You might want to look here for some lighting solutions:
http://www.lehmans.com
That loud noise you heard was my brain exploding.
It's a Sci-fi book titled Doomsday by Connie Willis. A woman researcher is sent back to the 1300s but something goes wrong and she ends up in the middle of the Black Plague. Very good reading - even if your not a sci-fi person.
see post #79 for the name of the book.
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