Posted on 02/12/2006 8:49:59 PM PST by presidio9
The warming of the world during the last century is greater – and more widespread – than any other shift in the global climate in the last 1,200 years, researchers reported Thursday.
The analysis of data from tree rings, fossil shells, ice cores and actual temperature measurements from 14 locations on three continents shows that the current warming trend is the most extensive change — warm or cold — since the time of the Vikings.
In their report in the current issue of the journal Science, climatologists Timothy Osborn and Keith Briffa of the University of East Anglia, home to the leading British climate research center, stop short of blaming the 20th-century warming on industrial emissions or other human factors.
But Osborn and Briffa say the geographic extent of the current warming, whatever the reason, is more widespread and more pronounced than the one that turned Greenland green 1,000 years ago.
Their analyses for tree ring and other climate "proxies" from Europe, Asia and North America do show two other pronounced climate shifts during the same period: the Medieval Warm Period from 890 to 1170 and the Little Ice Age, which gripped the Northern Hemisphere from 1580 to 1850.
The Medieval warming, which encouraged the Vikings to settle previously inhospitable regions of Greenland and Iceland, is sometimes cited by critics of modern global warming theories as evidence that the Earth can experience widespread warming independent of human activity.
"It's good that they acknowledge that the last thousand years contained two warm periods with a cold one in between," says S. Fred Singer, president of the Virginia-based Science Policy Project, which frequently disputes claims of global warming.
"But it still doesn't prove that the 20th century was unique," Singer said.
The Bush administration has acknowledged the widespread warming of recent decades, but has sought further research on the causes.
The administration also has declined to join 140 other nations in signing the Kyoto climate accord, which calls on industrial nations to reduce their industrial emissions.
While the study's emperature measurements only go back to the 1800s, researchers were able to reconstruct the Northern Hemisphere's climate back as far as the ninth century.
Researchers correlated temperature records with 14 long-term climate proxies, ranging from fossil shells in the Chesapeake Bay to tree rings in Mongolia.
"Both individually and taken as a whole, these reconstructions support the conclusion that it is likely that the late 20th century was the warmest period in the past millennium or longer," Osborn says.
Averaged across the globe, the increase in temperatures is numerically small — about one degree above normal and about two degrees warmer than during the late 1800s.
The increase, however, has been especially sharp in recent years, with all 10 of the warmest years on record occurring since the mid-1990s.
The warming has been linked to accelerated melting of mountain glaciers and polar ice sheets throughout the world, warmer sea surface temperatures, the earlier arrival of spring in the Northern Hemisphere and other changes.
Many scientists predict the warming will increase if man-made releases of carbon dioxide and other greenhouse gases are not curbed.
"Our research doesn't prove that increased CO2 is currently causing global warming, but oxygen isotopic measurements of ancient Earth temperatures suggest that this has caused global warming in Earth's past."
http://www.sciencedaily.com/releases/2002/12/021211084123.htm
You have described the dope growers of Humboldt County perfectly...
The Vikings caused global warming then caused the earth to cool down again. How? Plundering and looting. Setting towns on fire cause global warming. settleing down to count their loot with the pretty maidens they captured caused the earth to cool. We are not doing enough looting. Need to start now. Being the worlds nice guy is going to destroy the earth!
Nice rant, eh?
It wasn't the Vikings so much as their pets. That's right, the kitties. See, cats like to be warm. And cats, as any cat owner knows, control their humans. Even today. And so, though it was long ago in a faraway land, it was done.
Methane?
And anyone who has been in almost any country outside of the USA knows that what you say is the truth.
Maybe it was their diet?
Awesome, but you forgot volcanoes and the generations they kill, lol!
Those damn Minnesota Vikings...I knew it was their fault all along...GO RAIDERS...SAVE US ART SHELL!
All those Viking longboats caused atmospheric changes.
so there you are......it was this warm or warmer 1200 years ago....so what type of SUV's were they driving or did their Viking boats with the dragon heads have big Hemi's in them.
Bullsh_t... they didn't record weather in NYC til 1869.
Well, I agree that spring was early in January, but it was the shortest spring and summer in recorded history.
"consider that the Chinese fleet of the 1420's sailed around Greenland during" Could you please souce this?
The book is called "1421" by Gavin Menzies...the argument is fascinating -- draws upon multiple oddities in the historical record. Perhaps over-reaching in some ways, but certainly interesting reading.
Al Gore discovered Greenland.
The Viking era was about 1000 years ago. The earth is some 4 billion years old. So they are saying this warming trend is the biggest of the last 0.000025% of the earth's history. Wow, that tells us a lot.
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