Critically assess the importance of solar variability, volcanic Essay

Critically assess the importance of solar variability, volcanic eruptions and greenhouse gas concentrations as climate forcing f - Essay Example Climate change is brought about by many factors. These include circulation of the oceanic processes, solar variations, volcanic eruptions, plate tectonic activities and human factors. Studies to determine the level of climate change is done using observation and theorems. Factors that affect climate are called climate forcings (Yang et al,2000) .They are internal and external climate forcings; these forcings affect some parts of the environment faster or slower depending on the position of the given atmospheric location. The ocean is known to respond slowly to climate forcings. Forcings are either internal or external depending on the genesis of the process (Valet, 2003). Internal forcings include natural processes within the atmosphere like volcanic eruptions, tectonic plate movements, variations in solar radiations and concentration of greenhouse gas effects (Geel et al., 1999). External forcings are human activities that lead to the emission of dangerous gases into the atmosphere. There also are climate change feedbacks which are elements that act in three ways to climatic forcings (Orr, 1999). It can be sudden, where there occurs a sudden cooling effect occasioned by a high presence of volcanic ash in the atmosphere which will reflect sunlight and heat. It can be gradual, in this case, the water bodies become warm slowly; and then overflow. The third possibility is a combination of both fast and slow reactions, in such a situation a sudden cooling of ice is experienced in the Arctic Ocean followed by a sudden meltdown of the ocean ice (Grootes and Stuiver, 1997). Currently, we are in a period between two ice ages, and if there are no other influences, another ice age will occur in a time scale of thousands of years. The rate of global temperature change linked to astronomical forcing is approximated to be in the order of a few tenths of a degree Celsius per thousand years (Washington et al., 2001). Solar Variations Information on solar changes is obtained f rom cosmogenic radionuclide records. The variables used in this study illustrate how changes over periods of time have influenced the climatic conditions of given geographical regulates and the production of carbon dioxide. (Svensmark and Friis-Christensen, 1997). High powered galactic cosmic rays induce a reactivity series of nuclear reactions that produce cosmogenic radionuclide in the atmosphere. When elements carrying high energy hit oxygen and nitrogen in the atmosphere, Be (beryllium) is formed. Further reactions of this element with nitrogen form slow neutrons. The sun regulates the intensity of the galactic cosmic rays (GCR) that reaches the earth’s surface and in this way, affects the production of radionuclides in the atmosphere. After Be is formed, it combines with aerosols and hangs in the atmosphere for one to two years (Mc Hargue and Damon, 1997). Disparities in 10Be records between Antarctica and Greenland during 1950 AD have led to differing conclusions regard ing solar activity in this period (Lean, 1991). According to Greenland records, there was low 10 Be production after 1950 AD but in the Antarctic records, the trend is opposite. These 11-year averages of sunspot data and the neutron monitor show