CO₂ and global climate: Is history bunk?

The consensus that atmospheric carbon dioxide has been the driving force in global climate change is brought into question by a new reconstruction of tropical sea surface temperatures throughout the past 540 million years. Is it that currently accepted historic reconstructions of past carbon dioxide concentrations are unreliable, or are current climate simulations calibrated such that they give unreliable 'predictions' for what happened to past climate? The new results come from a database of oxygen isotope concentrations in calcite and aragonite shells which indicate that large oscillations in tropical sea surface temperature were in phase with the coming and going of ice ages, but at odds with predictions based on carbon dioxide as the cause.

Evidence for decoupling of atmospheric CO₂ and global climate during the Phanerozoic eon
JÁN VEIZER, YVES GODDERIS, LOUIS M. FRANÇOIS
Nature 408, 698-701 (7 December 2000)
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What drives climate?
LEE R. KUMP
Variation in the amount of CO₂ in the atmosphere is usually taken to be the main cause of climate change on geological timescales. The apparent exceptions to the link threaten to undermine that view.
Nature 408, 651-652 (7 December 2000)
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climate : Force of change not necessarily CO₂
A glimpse at the deep past hints that carbon dioxide might not always have caused global warming, reports Heike Langenberg.

7 December 2000 table of contents