New AWI Research Confirms: Climate Models Cannot Reproduce Temperatures Of The Last 6000 Years

By Dr. Sebastian Lüning, Prof. Fritz Vahrenholt and Pierre Gosselin

One of the main points of criticism of the CO₂-dominated climate models is that they fail to reproduce the temperature fluctuations over the last 10,000 years. This surprises no one as these models assign scant climate impact to major factors, i.e. the sun. As numerous IPCC-ignored studies show, the post-Ice Age temperature curve for the most part ran synchronously with solar activity fluctuations. The obvious discrepancy between modeled theory and measured reality has been brought up time and again.

The journal Climate of the Past Discussions has published a new paper written by a team led by Gerrit Lohmann of the Alfred Wegener Institute (AWI) in Bremerhaven, Germany. The group compared geologically reconstructed ocean-temperature data over the last 6000 years to results from modeling. If the models were indeed reliable, as is often claimed, then there would be good agreement. Unfortunately in Lohmann’s case, agreement was non-existent.

Lohmann et al plotted the geologically reconstructed temperatures and compared them to modeled temperature curves from the ECHO-G Model. What did they find? The modeled trends underestimated the geologically reconstructed temperature trend by a factor of two to five. Other scientists have come up with similar results (e.g. Lorenz et al. 2006, Brewer et al. 2007, Schneider et al. 2010).

The comprehensive temperature data collection of the Lohmann team distinctly shows the characteristic millennial scale temperature cycle for many regions investigated, see Figure 1 below. Temperatures fluctuated rhythmically over a range of one to three degrees Celsius. In many cases these are suspected to be solar-synchronous cycles, like the ones American Gerard Bond successfully showed using sediment cores from the North Atlantic more than 10 years ago. And here’s an even more astonishing observation: In more than half of the regions investigated, temperatures have actually fallen over the last 6000 years.

Figure 1: Temperature reconstructions based on Mg/Ca method and trends with error bars. From Lohmann et al. (2012).

What can we conclude from all this? Obviously the models do not even come close to properly reproducing the reconstructed temperatures of the past. This brings us to a fork in the road, with each path leading to a completely different destination: 1) geologists would likely trust their temperatures and have doubts concerning the reliability of the climate model. Or 2) mathematicians and physicists think the reconstructions are wrong and their models correct. The latter is the view that the Lohmann troop is initially leaning to. We have to point out that Gerrit Lohmann studied mathematics and physics, and is not a geo-scientist. Lohmann et al prefer to conjure thoughts on whether the dynamics between ocean conditions and the organisms could have falsified the temperature reconstructions, and so they conclude:

“These findings challenge the quantitative comparability of climate model sensitivity and reconstructed temperature trends from proxy data.“

Now comes the unexpected. The scientists then contemplate out loud if perhaps the long-term climate sensitivity has been set too low. In this case additional positive feedback mechanisms would have to be assumed. A higher climate sensitivity would then amplify the Milankovitch cyclic to the extent that the observed discrepancy would disappear, this according to Lohmann and colleagues. If this were the case, then one would have to calculate an even higher climate sensitivity for CO2 as well, which on a century-scale would produce an even higher future warming than what has been assumed by the IPCC up to now. An amazing interpretation.

The thought that the climate model might be fundamentally faulty regarding the weighting of individual climate factors does not even occur to Lohmann. There’s a lot that indicates that some important factors have been completely under-estimated (e.g. sun) and other climate factors have been grossly over-estimated (e.g. CO2). Indeed the word “solar” is not mentioned once in the entire paper.

So where does their thought-blockage come from? For one it is a fact that physicist Lohmann comes from the modeling side, and stands firmly behind the CO2-centred IPCC climate models. In their introduction Lohmann & colleagues write:

“Numerical climate models are clearly unequalled in their ability to simulate a broad suite of phenomena in the climate system […]“

Lohmann’s priorities are made clear already in the very first sentence of their paper:

“A serious problem of future environmental conditions is how increasing human industrialisation with growing emissions of greenhouse gases will induce a significant impact on the Earth’s climate.”

Here Lohmann makes it clear that alternative interpretations are excluded. This is hardly the scientific approach. A look at Lohmann’s resume sheds more light on how he thinks. From 1996 to 2000 Lohmann worked at the Max Planck Institute for Meteorology in Hamburg with warmists Klaus Hasselmann and Mojib Latif, both of whom feel very much at home at the IPCC. So in the end what we have here is a paper whose science proposes using modeled theory to dismiss real, observed data. Science turned on its head.

[Added: “SL wants to apologize to the authors of the discussed article for the lack of scientific preciseness in the retracted sentences.”  ]

From 1996 to 2000 Lohmann worked at the Max Planck Institute for Meteorology in Hamburg with warmists Klaus Hasselmann and Mojib Latif, both of whom feel very much at home at the IPCC.

[Note the above text was changed on 4/16/12 at 130PM PST as the request of Dr. Sebastian Lüning – Anthony]