Global Warming: CO2 vs Sun [chapter]

Georgios Florides, Paul Christodoulides, Vassilios Messaritis
2010 Global Warming  
Global Warming: CO2 vs Sun 53 structure. The climate is so sensitive to clouds that present models of global climate can vary in their global warming predictions by more than a factor of 3, depending on how clouds are modeled (Goddard Space Flight Center, 1999) . Cosmic rays During the 1990s Svensmark H. and Friis-Christensen E., presented a new astronomical cause for climate change, that of the cosmic ray hypothesis. Cosmic radiation originates from all luminous objects in the universe and it
more » ... omprises primary particles with very high energy (mainly protons, 92%, and alpha particles, 6%). When the ray particles reach the Earth they cause ionization in the upper layers of the atmosphere. The particles loose energy colliding with other particles in the atmosphere and many of the lower energy particles are absorbed by the atmosphere on their way down to the surface. Magnetic fields deflect these rays and since the solar wind expands the magnetic field of the Sun, the Earth is shielded more from the incoming cosmic rays. Solar wind increases in strength with sunspot activity. According to the cosmic ray hypothesis, periods with low solar activity would allow more cosmic radiation to reach the earth, more clouds (low clouds) would be formed and finally a lower global mean temperature would result, and vice versa. In examining the above-mentioned hypothesis the Danish National Space Center (DNSC, 2007), identified five external forcing parameters that are modulated by solar variability and have the potential to influence the Earth's lower atmosphere below 50 km. These are (a) the Total Solar Irradiance (TSI), (b) the Ultra-Violet (UV) component of solar radiation, (c) the direct input from the Solar Wind (SW), (d) the total Hemispheric Power Input (HPI) reflecting properties of precipitating particles within the magnetosphere, and (e) the Galactic Cosmic Rays (GCR). Their conclusion is that UV and GCR present a striking correlation with the global coverage of low clouds, over nearly two and a half solar cycles as shown in Fig. 29 . Currently, the National Space Institute of Denmark (DNSI, 2007) has been investigating the hypothesis that solar variability is linked to climate variability by a chain that involves the solar wind, cosmic rays and clouds. The reported variation of cloud cover was approximately 2% over the course of a sunspot cycle but simple estimates indicate that the resultant global warming could be comparable to that presently attributed to GHGs from the burning of fossil fuels. Recent work has directed attention to a mechanism involving aerosol production and the effects on low clouds. This idea suggests that ions and radicals produced in the atmosphere by cosmic rays could influence aerosol production and thereby cloud properties. Cosmic rays ionize the atmosphere, and an experiment performed at DNSI has found that the production of aerosols in a sample atmosphere with condensable gases (such as sulphuric acid and water vapor) depends on the amount of ionization. Since aerosols work as precursors for the formation of cloud droplets, this is an indication that cosmic rays influence cloud formation. As the National Space Institute of Denmark (2009) informs us, the European Organization for Nuclear Research, CERN, has currently been creating an atmospheric research facility at its Particle Physics laboratory. Called CLOUD, it will consist of a special cloud chamber exposed to pulses of high-energy particles from one of CERN's particle accelerators. Conditions prevailing the Earth's atmosphere will be recreated in CLOUD, and the incoming particles will simulate the action of cosmic rays. The main cloud chamber for the CLOUD facility is expected to begin operating in 2010.
doi:10.5772/10283 fatcat:2spcbjhxyrd65mnbl7csouzzzq