2006-02-28

Greenhouse Gas Release

University of California Santa Cruz
Author: James Zachos
Human activities are releasing greenhouse gases more than 30 times faster than the rate of emissions that triggered a period of extreme global warming in the Earth's past.
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Compounding this concern is the possibility that higher temperatures could retard ocean mixing, further reducing the ocean's capacity to absorb carbon dioxide. This could have the kind of "positive feedback" effect that climate researchers worry about: reduced absorption, leaving more carbon dioxide in the air, causing more warming.
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2006-02-17

Models Underestimate Future Warming

Woods Hole Oceanographic Institution
Lead author: Karen Bice
Where published: Paleoceanography, American Geophysical Union
Scientists have found evidence that tropical Atlantic Ocean temperatures may have once reached 107°F (42°C)—about 25°F (14°C) higher than ocean temperatures today and warmer than a hot tub. The surprisingly high ocean temperatures, the warmest estimates to date for any place on Earth, occurred millions of year ago when carbon dioxide levels in Earth’s atmosphere were also high, but researchers say they may be an indication that greenhouse gases could heat the oceans in the future much more than currently anticipated. The study suggests that climate models underestimate future warming.
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2006-02-10

Significance of 20th Century Warming

University of East Anglia
Lead author: Timothy Osborn, Keith Briffa
Where published: Science

The most significant and longest duration feature during the last 1200 years is the geographical extent of warmth in the middle to late 20th century. Positive anomalies during 890 to 1170 and negative anomalies during 1580 to 1850 are consistent with the concepts of a Medieval Warm Period and a Little Ice Age, but comparison with instrumental temperatures shows the spatial extent of recent warmth to be of greater significance than that during the medieval period.

abstract