Skip to comments.Global warming biggest since Viking era
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.
So surely the Vikings must have done something that caused a warming cycle.... (or not.)
Yenga Henga Shmormy. De vurld is lots more vormy.
What did the Vikings do to make it warmer back then?
Sounds like the Vikings had a green house gas problem too. :)
I think it was that boat cruise they took at the end of last season's training camp that heated up things
I thought it might be due to training camp...
It isn't selling.
Especially when an "Al Gore" moment occurs and the news release hits the public during a major blizzard.
Was Bush around back then?
"What did the Vikings do to make it warmer back then?"
Must have been all the villages they burned after they raped and pillaged.
Yup. Complete with baggie-like outfield fences too (ha)
I'm glad I kept reading. I thought they were referring to Eller, Page, and Marshall.
***What did the Vikings do to make it warmer back then?****
All those Viking funerals - the deceased pushed out to sea on a burning ship...