re:look – Aufriß – paper analysis
Dr. Philipp Lengsfeld
Primary source: A. Lauberau and H. Iglev, TU Munich, Germany, ‘On the direct impact of the CO2 concentration rise to the global warming’ EPL 104 29001, 2013
The climate research literature seems to overflow with manuscripts. However, contrary to intuition this does not seem to strengthen the understanding of the underlying science.
For instance, on the key question of the relevance and importance of greenhouse-gas driven anthropogenic global warming (GHG-AGW) there are surprisingly few works actually tackling this scientific challenge.
re:look climate thus aims to at least highlighting recent key works which either strongly support or significantly weaken the GHG-AGW hypotheses.
The above referenced paper is a peer-reviewed publication from late 2017, originating from physicists from a well-respected climate research institution in Germany, falls according to our assessment and the authors own conclusions into the category ‘significantly weakens current GHG-AGW-hypothesis’.
Here is a short re:look climate summary of the paper and its key findings:
The work by Lauberau and Iglev, 2013 sets out to investigate direct impact of CO2 on global warming using spectroscopy and modelling.
The paper combines the precise measuring of optical properties of CO2 gas with established greenhouse effect models, which were extended to include temperature variations in the atmosphere. 4 and 5 layer models were developed and computed. For details of the optical measurements and the greenhouse effect modelling please refer to the original manuscript.
The results of the optical measurement input and the modelling calculations were compared to observed global temperatures in the recent time period (1880-2010), which saw a temperature increase of 1.2K.
According to Lauberau and Iglev approximately 0.26 K of the observed 1.2K increase can be attributed to the far-infrared properties of CO2, even already considering a H2O feedback mechanism. Thus, using the 5-layer model of the atmosphere and a thermal equilibrium of approx 288 Kelvin, the contribution to warming directly to be linked to CO2 is less then 33% of the total temperature change within the observed time period.
Authors conclusions and considerations:
The authors state the summary of their work plainly: “Our results suggest that CO2 is not predominant for the terrestrial temperature increase. Only a moderate effect of less than 33% is found.”
The authors speculate that more realistically, BC (black carbon) adsorption in the far infrared should be considered as a driving factor as their calculation model suggests that a decrease of this transmission window would indeed be sufficient to lead to a temperature raise of up to 1 Kelvin. Black carbon component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter). Black carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot.
re:look climate considerations:
This work is clearly challenging the current assumptions around conventional GHG-AGW hypothesis. Further investigations and modelling is likely needed to resolve the underlying controversy.
Follow-up research of the authors:
The researchers Laubereau and Iglev follow-up on their initial investigation by evaluating the impact of polar and antarctic sea ice retreat and consequently changed/reduced albedo employing a simple model. Finally, the authors postulate that a significant contribution to polar ice reduction may be from the effect of surface pollutants (black carbon/BC). All follow-up work has been published on non-peer reviewed open source to date (see references).
It is noteworthy that the authors in essence have created a consistent hypothesis for the recently observed rise in global temperature pointing at a significant role of reduced polar sea ice, maybe to a significant portion fueled by anthropogenic surface pollution (black carbon). The authors ascribe to the conventional GHG-AGW effect a percentage of 25-30%.
Laubereau, A. and H. Iglev 2013. On the direct impact of the CO2 concentration rise to the global warming. EPL 104 29001.
Laubereau, A. and H. Iglev 2017. Arctic Sea Ice and the Mean Temperature of the Northern Hemisphere. arXiv: Geophysics.
Laubereau, A. and H. Iglev 2018. Estimate of the Globing Warming Caused by the Retreat of Polar Sea Ice. arXiv: Geophysics.
Laubereau, A. and H. Iglev 2018. On the Warming of the Southern Hemisphere since 1955 and Recent Slowing-Down: Role of Sea Ice, Sun Spot and El Nino Variability. arXiv: Geophysics.
Laubereau, A. and H. Iglev 2019. An Estimate of the Surface Pollution of the Arctic Sea Ice. arXiv: Geophysics.