20th Century Warmest In 1200 Years

gcranston writes "Research from the University of East Anglia in Norwich, U.K. shows that the 20th century was the warmest for the northern hemisphere since approximately 800AD. Historical climate data were calculated from weather 'proxies' such as tree rings, ice cores, and seashells from Europe, Asia, and North America, and attempted to address the shortcomings of earlier studies. The findings support the argument for global warming as a result of human interference rather than natural climate change."

Comments

Food for thought

[MyNymWasTaken]

There has been a 19.4% increase in the mean annual concentration of CO2 in the atmosphere from 1959 to 2004.

During the 1959-2002 period, the total CO2 emissions equaled ~220 gigatons; ~14% of the atmospheric CO2 in 1959.

In 2002, Humanity pumped 7 gigatons (6975 megatons) of CO2 into the atmosphere. That is almost 4 times the emissions from 50 years ago (1952: 1795 megatons), and is more than was released from 1751-1886 (136 years: 6732 megatons).

There is a close correlation between Antarctic temperature and atmospheric concentrations of CO2. The extension of the Vostok [antarctic ice core] CO2 record shows the present-day levels of CO2 are unprecedented during the past 420 thousand years.

Cites:
Atmospheric carbon dioxide record from Mauna Loa [ornl.gov]
Global CO2 Emissions [ornl.gov]
Historical carbon dioxide record from the Vostok ice core [ornl.gov]
Earth's atmosphere [wikipedia.org]

Re:Food for thought

[OverlordQ]

"From 1986 to 2000 central Antartic valleys cooled .7 C per decade with serious ecosystem damage from cold"

'Antartic climate cooling and terrestrial ecosystem response' Nature 415: 517-20

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"Both satellite data and ground stations show slight cooling over the last 20 years."

'Variability and trends in ANtartic surface temperates from in situ and satellite infared measurements' Journal of CLimate, 13: 1674-96

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"Side-looking radar measurements show West Antartic ice is increasing at 26.8 gigatons/yr. Reversing the melting trend of the last 6000 years"

'Positive mass balance of the Ross Ice Streams, West Antarticia' Science 295: 476-80

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"During the last four interglacials, going back 420,000 years, the Earth was warmer than it is today."

'CLimate and atmospheric history of hte past 420,000 years from the Vostok Ice Core, Antartica' Nature 399: 429-36

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"Less Antartic ice has melted today than occured furing the last interglacial"

'Radiocarbon constrains on ice sheet advance and retreat in the Weddell Sea, Antartica' Geology 27: 179-82

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The Sahara has shrunk since 1980

'Africans go back to the land as plants reclaim the desert' New Scientist 175, 21 September 2002.

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On the other hand sea level *is* rising, as it has been for the last 6000 years since the satart of the Holocene, about 10-20 cm every 100 years.

http://www.csr.utexas.edu/gmsl/main.html

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Hell I could throw in stats and references about the decreases in tropical storm activity, but I think I've made my point enough.

Re:Interesting...

[slumberer]

They're saying that it was every bit as warm in 800 A.D. then? That kinda discounts their theory that modern man is causing global warming then doesn't it?

From TFA Reliable records from trees and other sources go back only about 1,200 years. So no, they're NOT saying that it was as warm in 800 AD. They are saying that this is the warmest year since 800 AD and that they don't have have any reliable records before that! This is a big difference.

I know that this is Slashdot but you really should try reading the article before making inflamatory statements like "Another crackpot theory bites the dust."