Posted on 11/06/2006 10:11:27 PM PST by neverdem
In recent years, scientists have made sizable gains in what was once considered an impossible art reconstructing the history of Earths atmosphere back into the dim past. They can now peer across more than a half billion years.
The scientists have learned about the changing makeup of the vanished gases by teasing subtle clues from fossilized soils, plants and sea creatures. They have also gained insights from computer models that predict how phenomena like eroding rocks and erupting volcanoes have altered the planets evolving air. Its getting a lot more attention, Michael C. MacCracken, chief scientist of the Climate Institute, a research group in Washington, said of the growing field.
For the first time, the Intergovernmental Panel on Climate Change, a United Nations group that analyzes global warming, plans to include a chapter on the reconstructions in its latest report, due early next year.
The discoveries have stirred a little-known dispute that, if resolved, could have major implications. At issue is whether the findings back or undermine the prevailing view on global warming. One side foresees a looming crisis of planetary heating; the other, temperature increases that would be more nuisance than catastrophe.
Perhaps surprisingly, both hail from the same camp: scientists who study the big picture of Earths past, including geologists and paleoclimatologists.
Most public discussions of global warming concentrate on evidence from the last few hundred or, at most, few thousand years. And some climate scientists remain unconvinced that data from the deep past are solid enough to be relevant to the debates.
But the experts who peer back millions of years, though they may debate what their work means, do agree on the relevance of their findings. They also agree that the eon known as the Phanerozoic, a lengthy span from the present to 550 million...
(Excerpt) Read more at nytimes.com ...
This kind of irresponsible science is not helpful towards advancing the fight against global warming. /sarcasm/
I'm not sure if I pinged you.
The reason this is going to be in the upcoming IPCC ...
... is so they can rewrite the climate history of the planet again.
Just like Michael Mann's Hockey Stick attempted to do away with the Medieval Warm Period and the Little Ice Age, the IPCC will attempt to rewrite the CO2 content of the historical atmosphere.
The 7,000 ppm will be replaced with a nice 450 ppm.
Just watch.
ping
Evidence for decoupling of atmospheric CO2 and global climate during the Phanerozoic eon
Atmospheric carbon dioxide concentrations are believed to drive climate changes from glacial to interglacial modes, although geological and astronomical mechanisms have been invoked as ultimate causes. Additionally, it is unclear whether the changes between cold and warm modes should be regarded as a global phenomenon, affecting tropical and high-latitude temperatures alike, or if they are better described as an expansion and contraction of the latitudinal climate zones, keeping equatorial temperatures approximately constant. Here we present a reconstruction of tropical sea surface temperatures throughout the Phanerozoic eon (the past 550 Myr) from our database of oxygen isotopes in calcite and aragonite shells. The data indicate large oscillations of tropical sea surface temperatures in phase with the coldwarm cycles, thus favouring the idea of climate variability as a global phenomenon. But our data conflict with a temperature reconstruction using an energy balance model that is forced by reconstructed atmospheric carbon dioxide concentrations. The results can be reconciled if atmospheric carbon dioxide concentrations were not the principal driver of climate variability on geological timescales for at least one-third of the Phanerozoic eon, or if the reconstructed carbon dioxide concentrations are not reliable.
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