But this research does argue for a different path to global warming in the past, which means that estimates of the planet's sensitivity to various levels of CO2 based on measurements from the Ice Age may be flawed, Stott argues. "We are a long way from refining the climate sensitivity to a doubling of CO2 [that] is going to take place in the next 100 years," he notes.
Stott plans to investigate how ocean warming led to a CO2 rise in the past, research that could also have implications for present climate change. But one impact of the new finding is already clear, Stott says: "a regional change in climate can propagate into a global response."
With Arctic ice retreating more and more as local summers heat up, exposing ever more cold northern waters to warming sunshine—along with a host of other regional changes—it remains to be seen exactly how sensitive global climate really is. "We just don't know very well," Stott acknowledges, "how the climate itself, which is much more than temperature, is going to behave."
*Article updated on 9/28/07.
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Add CommentNow the question should be asked,"Why is the Artic Ocean warming?" You almost touched on it by describing Milankovitch cycles. The warble is caused by an increase in magma in the northern or southern latitudes. As proof of this has not the magnetic north deviated 33 feet towards Canada in recent years? A recent expedition to the Arctic discovered thousands of volcanic vents along the Kobienski and Gakkel ridges. In the case of the Gakkel Ridge they expected to see nothing because of the way the plates converged. But they found thousands of vents. Could this be the true reason for oceanic warming? The extreme increase of underwater volcanic activity is well documented.
Reply | Report Abuse | Link to this1999. "Ice Core records of Atmospheric CO2 Around the
Reply | Report Abuse | Link to thisLast Three Glacial Terminations"
(Fischer & al., Science 283, 12. marts 1999, p.1712ff)
also told us (9 years ago and desperately challenged by IPCC) that temperature lagged CO2 by about 800 years.
The resultats are based on deltaD in the Vostok ice core
(delta Deuterium = variations in the proportion of 2/1H (heavy hydrogen) to the common 1/1H isotope in the water before it froze) - a standard indicator of water temperature.
Correction: In English "12. marts" is "March 12" - sorry about that :-)
Reply | Report Abuse | Link to thisThose volcanic vents probably have as little heating effect as do car exhausts, or central heating flues, compared to the effects of CO2.
Reply | Report Abuse | Link to thisDeep Magma is solid due to the intense pressure at depth and migrates laterally at but a few millimeters per year. All over the world the earth's core is evacuating heat constantly. What causes deep 'Hot Spots' is not yet clear. Mauna Loa is a hot-spot, having little effect on ocean temperatures....
Mr. Schmidt seems a bit jumpy, as if every new scientific report is a challenge on global warming: "says climatologist Gavin Schmidt of NASA's Goddard Institute of Space Studies. 'But it has no direct impact on attribution of 20th century warming.' "
Reply | Report Abuse | Link to thisNo doubt. It is about the end of the last ice age and it probably bears upon anticipation of the next one. Schmidt's opinion ought not to have been invited or published here as if it were some sort of public peer review.
However, he is right to think that a great many people are going to admit the possibility that this mysterious heat source still exists and is still driving, in part, climate variability. He ought to have said, "That's fascinating; let's discover the heat source." We may need it to stave off the next ice age.