Tuesday 22 February 2011

Natural Causes of Global Warming


Global warming is a major environmental issue today. All over the world there is a projected continuation of deterioration, with respect to surface temperature and subsequent, drastic climatic variations. The increase of global surface temperature is alarming and not totally the result of the greenhouse gases that are anthropogenic in nature. The temperature increase has been screaming attention since the middle of the last century. Natural phenomena like solar variation and the 'Feedback' effect are also responsible for the occurrence. The gigantic steps taken in the field of industrialization and greenhouse gas emissions have added to the CO2 (carbon dioxide) in the atmosphere.

Solar Variation:

Climate changes in orbital forcing and solar luminosity are also responsible for variation in surface temperatures. Variations in solar activity is being held responsible for most of the global warming, since the 1950s. According to recent research, solar output variations are possibly amplified by galactic cosmic rays. The magnetic activity in and around the sun plays a major role in deflecting cosmic rays. These in turn are responsible for cloud condensation and climatic changes. Increased solar activity could be the result of excessive warming of the stratosphere. Solar cycles lead to an increase in brightness and heat generation. The light and heat get trapped in the stratosphere. The relation between solar radiation and global warming however, is yet to be proven and is one of the most speculated topics deliberated upon in recent times. The link between changes in cosmic rays and temperature is being studied alongside human induced reasons for the phenomenon.

'Feedback' Effect:

It has been observed that warming only results in further warming and the resultant 'positive feedback' culminates in global warming. The opposite reaction is referred to as 'negative feedback'. Water vapor is the outcome of positive feedback. An increase in saturation of vapor pressure results in a subsequent increase in the quantity of atmospheric water vapor. This makes the atmosphere warmer and a stagnancy in the relative humidity. Feedback results in the emission of infrared radiation from clouds back to the earth's surface. This facilitates further warming, depending on the type of cloud and the altitude. Longwave radiation that is emitted or released from the upper atmosphere is much less than the lower layers. The radiation that is emitted from the lower atmosphere thus gets reabsorbed by the surface. Subsequently, when global temperatures increase, the ice caps near the poles melt and add to the sea water level. Land and open water absorb solar radiation extensively and this has led to the arctic shrinkage.

Implications of Global Warming:

Scientists work on fluid dynamics and transfer of radioactivity to study climate sensitivity. Human-caused emissions add to positive feedback and this results in long and short-term changes in the natural climate cycles. The causes of climate change in recent times is largely due to natural and human induced phenomena. It is now clearly observed that specific global weather events are related to global warming. Increase in global temperature has surfaced in the form of melting glaciers and a rise in sea level, variations in precipitation patterns and flooding and numerous other extreme weather events.

Neglect on our part to address reduced streamflows and disease vectors, related to global warming, will have a profound effect on our natural environment. It is essential to study the natural causes for this phenomenon and since little or nothing can be done about them, reduce the human-generated causes for environmental pollution that add to the problem. Geo-engineering is a very essential part of environmental science, for quick remediation of the effects of global warming. Ocean acidification, extinction concerns and disrupted food webs need to be sorted and treated amidst this awareness.