The latest paper being touted by the global warming skeptic crew is by a couple of petroleum engineers named Khilyuk and Chilingar and concludes
The current global warming is most likely a combined effect of increased solar and tectonic activities and cannot be attributed to the increased anthropogenic impact on the atmosphere. Humans may be responsible for less than 0.01Â°C (of approximately 0.56Â°C (1Â°F) total average atmospheric heating during the last century)
But what is the basis for this conclusion? Well, they work out total man-made CO2 emissions and …
Recalculating this amount into the total anthropogenic carbon dioxide emission in grams of CO2, one obtains the estimate 1.003Ã—1018 g, which constitutes less than 0.00022% of the total CO2 amount naturally degassed from the mantle during geologic history. Comparing these figures, one can conclude that anthropogenic carbon dioxide emission is negligible (indistinguishable) in any energy-matter transformation processes changing the Earth’s climate.
If those anthropogenic carbon dioxide emissions had been spread over several billion years then, yes, the effect would be negligible, but they’ve all happened over the last two centuries and have increased atmospheric CO2 by 30%. This is a real embarrassment for the journal that published this.
Nexus 6 has more details.
Update: Aeschbach-Hertig has published a devastating rebuttal in the same journal, which concludes:
It is astonishing that the paper of Khilyuk and Chilingar (2006) (as well as Khilyuk and Chilingar 2004, for that matter) could pass the review process of a seemingly serious journal such as Environmental Geology. Such failures of this process, which is supposed to guarantee the quality of published literature, are likely to damage the reputation of this journal.