New research keeps being added to the global warming science facts as we know them - a new Siberian study finds that climate has had frequent severe changes in the past and that extreme warm periods can't be explained by greenhouse gases (CO2)
(click on image to enlarge - source)
Read here. The image on the left is Lake El'gygytgyn in Siberia. Scientists have been able to extract high resolution sediment cores from the lake that have recorded climate changes over the last 2+ million years.
From their analysis, a team of scientists (Melles et al.) have documented at least 8 significant warming periods in the past, with some exceeding modern temperatures by 5 degrees. The research indicates these warming periods can last for thousands of years without the aid (ie, cause) of increased levels of atmospheric CO2.
"Furthermore, the paper states, "Climate [model] simulations show these extreme warm conditions are difficult to explain with greenhouse gas [CO2] and astronomical forcing [solar insolation] alone." The paper also finds the Arctic warming occurred simultaneously with Antarctic warming, indicating an interconnected, global phenomenon. Implications of the paper include: 1) The globe has been much warmer without human influence during multiple periods over the past 2.8 million years, 2) IPCC climate models are incapable of reproducing past temps and therefore unable to project future temps, and 3) global warming far exceeding alarmist IPCC projections has occurred several times in the past without triggering any "tipping points."" [Martin Melles, Julie Brigham-Grette, Pavel S. Minyuk, Norbert R. Nowaczyk, Volker Wennrich, Robert M. DeConto, Patricia M. Anderson, Anthony Coletti,Timothy L. Cook, Eeva Haltia-Hovi, Maaret Kukkonen, Anatoli V. Lozhkin, Peter Rosén, Pavel Tarasov, Hendrik Vogel, Bernd Wagner 2012: Science]