Guest Blog by David Evans, Science Speak

Our scientific understanding of global warming has gone through three stages:
1. 1985 – 2003. Old ice core data led us strongly suspect that CO2 causes global warming.
2. 2003 – 2007. New ice core data eliminated previous reason for suspecting CO2. No evidence to suspect or exonerate CO2.
3. From Aug 2007: Know for sure that greenhouse is not causing global warming. CO2 no longer a suspect.

The paper discusses how the ice core changes, missing greenhouse signature in the real data and the recent waning of the warming all suggest that carbon emissions are not behind the changes we have experienced in recent decades.

See larger image here.

The IPCC 2007 report (the latest and greatest from the IPCC) is based on all scientific literature up to mid 2006. The Bali Conference is the bureaucratic response to that report. Too bad that the data has changed since then! See the full paper here.

David Evans, a mathematician, and a computer and electrical engineer, is head of Science Speak. David is also a former believer in man-made warming who converted to skeptic.