Thursday, May 1, 2014

Global Climate Change and its Impact on the East Mountains


                 As the Earth cycles through its natural patterns, the sun’s rays reach the planet in different ways.  No matter where in the cycle the Earth is, radiation from the sun enters the Earth’s atmosphere in short waves and exits as long wave radiation.  Radiation is either reflected or absorbed by the surface of the Earth depending on the materials it encounters (i.e: air, land, or water).  Albedo is the reflectivity of materials to the sun’s rays.  High albedo means high reflectivity which means little heat absorption.  For example, the albedo of clouds is very high because clouds are light in color and made of water generally resistant to short wave absorption.  Clouds reflect radiation from both sides.  They reflect radiation from the sun back into space but also reflect radiation from the Earth back to the surface.  Albedo impacts temperatures on Earth by affecting the amount of radiation within the system.  New Mexico often doesn’t have the protection of clouds so temperatures vary greatly from day to night.



                Each of the life zones of the East Mountains differ in temperature partly because of elevation and latitude but also because of albedo.  In the life zones higher up on the mountainside, the concentration of dark green trees would lead one to expect higher temperatures, however very little sunlight reaches the forest floor and so it is not being absorbed by the Earth.  In the winter, this life zone is often covered in snow which has a high albedo and leads to overall cooling in the area.  The life zone just below that often has cloud cover in the morning preventing heat radiation from reaching the Earth but then loses its cloud cover at night allowing the Earth to cool off which leads to higher temperatures than the first zone but lower temperatures than the life zones below.  The transitional life zone has trees that are less dense, allowing more sunlight to penetrate and reach the Earth.  This life zone rarely has high winds cooling off the area making it warmer than the top of the mountain.  The lowest life zone has sparse tree cover but also has an abundance of grasses with low albedo.  Heat is usually absorbed during the day resulting in high temperatures in the afternoon but heat is also lost while the sun is set because there are not usually clouds in the atmosphere to hold the heat in. 



 

                The long wave radiation that the Earth emits is generally stopped by gases in the atmosphere.  Greenhouse gases are the gases in the atmosphere whose material compound keep heat in and create the greenhouse effect.  The greenhouse effect is when radiation is absorbed by compounds in the atmosphere and reiterated all over the Earth, resulting in an overall increase in temperature.  Contrary to popular belief, the greenhouse effect is necessary and natural.  Without it, the Earth would cool uncontrollably at night and make most environments inhospitable.  However, the greenhouse effect is often coupled with global warming as a root cause of temperature increases today that are outside cyclical circumstances.  CO2 or Carbon Dioxide is the most disputed greenhouse gas.  CO2 is a compound in the atmosphere that “loves” long wave radiation.  Air pollution from humans contributes greatly to a rise in CO2 concentration in the atmosphere and therefore an increase in the greenhouse effect.  For example, burning coal for energy releases carbon into the air and contributes to higher temperatures. 

                Many people argue that CO2 concentration has nothing to do with the greenhouse effect. But others argue that the composition of the atmosphere is important. Evidence on Earth suggests that CO2 concentration is linked directly to temperature.  When CO2 levels rise so does temperature.  Rising temperatures on a global scale is called global warming.

                Global warming is a concept of increasing temperatures and is impacted by cyclical events such as Milakovitch Cycles as well as the compounds in the Earth’s atmosphere and the effect of albedo.  Sometimes circumstances synchronize to create constant warming or cooling conditions over thousands of years.  However, human activities contribute to the out of control global temperature increase that is happening today.  In today’s circumstances, carbon levels are in fact rising naturally.  However, carbon levels that sustain human life in the past have never risen above 280 parts per million.  Today carbon levels are at about 390.1 parts per million.  This shows that the carbon concentration in the atmosphere is not entirely natural.  Temperatures are also rising resulting in overall global warming.     



                Global warming can have serious repercussions on the global environment such as melting ice caps, global sea rising, and plant and animal species going extinct because of changing conditions.  Species loss all over the world indicate very fast climate change.  Species today are going extinct at nearly one thousand times the natural rate.  This is evidence to further the claim that humans are responsible for the rise in global temperatures.  As countries go through industrial revolutions, they increase their carbon emissions quickly.  Not only are humans emitting carbon into the air, they’re also inhibiting the ability of the Earth to filter out that carbon.  A carbon sink is a location or material that contains carbon dioxide and effectively keeps it from being in the atmosphere.  For example, plants take in CO2 and release O2 into the air, incorporating the carbon into their tissue.  Rain forests are enormous carbon sinks.  Human activity and the deforestation of many rain forests, destroys natural solutions to carbon pollution and exacerbates the problem. 

                Overall, a combination of human activity and Milankovitch cycles have caused carbon levels to rise which has led to a rise in global temperatures.  This all affects the life zones in the East Mountains.  An example of this is the bark beetle problem.  Constant warm winters have allowed the bark beetle population to grow unchecked by freezing temperatures.  As a result, the trees in the area can no longer compensate for the large population of beetles.  This weakens the trees and increases the likelihood of forest fires which destroys natural habitats for animals.  Natural global warming is "ok" but when it is out of control, as we can see with local examples, it is up to people to intervene.  If humans change their habits, the problem can still be solved.

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