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(updated 13th January 2004)
SANTA CRUZ,
CA – Scientists have filled in key piece of global climate picture for a
period of 55 millions years ago that is considered one of the most abrupt
and extreme episodes of global warming in Earth’s history, according to a
University of California, Santa Cruz, professor.
The new results from an analysis of sediment cores
from the ocean floor are consistent with theoretical predictions of how
Earth’s climate would respond to rising concentrations of greenhouse gases
in the atmosphere, says James Zachos, professor of Earth’s sciences at the
university.
The researchers analyzed sediments
deposited on the ocean floor during a period known as the Paleocene-Eocene
Thermal Maximum, when a massive release of heat-trapping greenhouse gases is
thought to have triggered a runaway process of global warming. Climate
theory predicts that the increase in green house gases would have caused
temperatures to rise all over the planet, with greater increases in sea
surface temperatures at high latitudes than at low latitudes.
The
research provides important backing for the climate models that scientists
are using to predict the effects of the current rise in atmospheric carbon
dioxide due to industrial emissions, Zachos said. “The predictions from the
models seem to be consistent with the geologic record, so I’d say greenhouse
climate theory is alive and well,” he said. “People have raised questions
about how accurate these models are in terms of handling heat transport in
response to rising greenhouse gases, but this study indicates that climate
people have got it rights or close to that.”
Armstrong EcoNews
Editorial |
