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The Intergovernmental Panel on Climate Change assumes that the inclining atmospheric CO2 concentration over recent years was almost exclusively determined by anthropogenic emissions, and this increase is made responsible for the rising temperature over the Industrial Era. Due to the far reaching consequences of this assertion, in this contribution we critically scrutinize different carbon cycle models and compare them with observations. We further contrast them with an alternative concept, which also includes temperature dependent natural emission and absorption with an uptake rate scaling proportional with the CO2 concentration. We show that this approach is in agreement with all observations, and under this premise not really human activities are responsible for the observed CO2 increase and the expected temperature rise in the atmosphere, but just opposite the temperature itself dominantly controls the CO2 increase. Therefore, not CO2 but primarily native impacts are responsible for any observed climate changes.
Energie, die Basis unseres Lebens, war zusammen mit den dafür eingesetzten Ressourcen und dem Klima das Thema eines Symposiums am 8. November 2012 in Erlangen. In Deutschland werden die von der Politik gestellten Fragen zur langfristigen Energieversorgung und zum Klimawandel mit großem Eifer in der Öffentlichkeit diskutiert, zu denen, entgegen der verbreiteten Meinung, kein wissenschaftlicher Konsens besteht. Folgerichtig durfte sich das Symposium auch nicht anmaßen, festzustellen, was richtig und was falsch sei. Namhafte Fachleute waren gebeten, die wichtigsten, immer wieder vorgebrachten Argumente und politischen Vorgaben auf ihre Verträglichkeit mit den Erkenntnissen der Wissenschaft und dem Stand der Technik zu prüfen. Die Technische Fakultät an der Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) und der VDI/VDE-Arbeitskreis Gesellschaft und Technik (GuT) haben die Initiative ergriffen, die komplexen Zusammenhänge dieser Thematik in einem Symposium der Öffentlichkeit vorzustellen und zu erklären. Im vorliegenden Band sind fünf Vorträge des Symposiums veröffentlicht.
We present detailed line-by-line radiation transfer calculations, which were performed under different atmospheric conditions for the most important greenhouse gases water vapor, carbon dioxide, methane, and ozone. Particularly cloud effects, surface temperature variations, and humidity changes as well as molecular lineshape effects are investigated to examine their specific influence on some basic climatologic parameters like the radiative forcing, the long wave absorptivity, and back-radiation as a function of an increasing CO2 concentration in the atmosphere. These calculations are used to assess the CO2 global warming by means of an advanced two-layer climate model and to disclose some larger discrepancies in calculating the climate sensitivity. Including solar and cloud effects as well as all relevant feedback processes our simulations give an equilibrium climate sensitivity of Cs = 0.7°C (temperature increase at doubled CO2) and a solar sensitivity of Ss = 0.17°C (at 0.1% increase of the total solar irradiance). Then CO2 contributes 40% and the Sun 60% to global warming over the last century.
We investigate the interaction of infrared active molecules in the atmosphere with their own thermal background radiation as well as with radiation from an external blackbody radiator. We show that the background radiation can be well understood only in terms of the spontaneous emission of the molecules. The radiation and heat transfer processes in the atmosphere are described by rate equations which are solved numerically for typical conditions as found in the troposphere and stratosphere, showing the conversion of heat to radiation and vice versa. Consideration of the interaction processes on a molecular scale allows to develop a comprehensive theoretical concept for the description of the radiation transfer in the atmosphere. A generalized form of the radiation transfer equation is presented, which covers both limiting cases of thin and dense atmospheres and allows a continuous transition from low to high densities, controlled by a density dependent parameter. Simulations of the up- and down-welling radiation and its interaction with the most prominent greenhouse gases water vapour, carbon dioxide, methane, and ozone in the atmosphere are presented. The radiative forcing at doubled CO2 concentration is found to be 30% smaller than the IPCC-value.
We present an advanced two-layer climate model, especially appropriate to calculate the influence of an increasing CO2-concentration and a varying solar activity on global warming. The model describes the atmosphere and the ground as two layers acting simultaneously as absorbers and Planck radiators, and it includes additional heat transfer between these layers due to convection and evaporation. The model considers all relevant feedback processes caused by changes of water vapour, lapse-rate, surface albedo or convection and evaporation. In particular, the influence of clouds with a thermally or solar induced feedback is investigated in some detail. The short- and long-wave absorptivities of the most important greenhouse gases water vapour, carbon dioxide, methane and ozone are derived from line-by-line calculations based on the HITRAN08-databasis and are integrated in the model. Simulations including an increased solar activity over the last century give a CO2 initiated warming of 0.2 °C and a solar influence of 0.54 °C over this period, corresponding to a CO2 climate sensitivity of 0.6 °C (doubling of CO2) and a solar sensitivity of 0.5 °C (0.1 % increase of the solar constant).
Climate scientists presume that the carbon cycle has come out of balance due to the increasing anthropogenic emissions from fossil fuel combustion and land use change. This is made responsible for the rapidly increasing atmospheric CO2 concentrations over recent years, and it is estimated that the removal of the additional emissions from the atmosphere will take a few hundred thousand years. Since this goes along with an increasing greenhouse effect and a further global warming, a better understanding of the carbon cycle is of great importance for all future climate change predictions. We have critically scrutinized this cycle and present an alternative concept, for which the uptake of CO2 by natural sinks scales proportional with the CO2 concentration. In addition, we consider temperature dependent natural emission and absorption rates, by which the paleoclimatic CO2 variations and the actual CO2 growth rate can well be explained. The anthropogenic contribution to the actual CO2 concentration is found to be 4.3%, its fraction to the CO2 increase over the Industrial Era is 15% and the average residence time 4 years.