The Human Factor of Global Warming
The Human Factor of Global Warming
Global warming has been a growing concern for many over the last several decades. The effects of global warming are evident and broad, with historical research dating the first global warming crisis back 56 million years ago, better known as the Paleocene-Eocene Thermal Maximum, or PETM (Jardine, 2011). Research from the composition of sediments of fossils shells of marine organisms conclude that carbon dioxide trapped within our atmosphere, increased global temperatures by more than 5 degrees in just a few thousand years (Jardine, 2011). While global warming may not be in question, many scientists have questioned the actual global warming effect theory due to many uncertainties. Whether or not humans are inherently responsible is debatable and subject to skepticism along with whether or not the human race can influence the outcome of such. *
The first theory on global warming dates back to 1886. A Swedish chemist by the name of Svante Arrhenius had a theory that a rise in atmospheric carbon dioxide emissions as a result from combusting fossil fuels could enhance the average surface temperature of the earth (Maslin, 2004). While close to half the solar radiation reaching the earth’s surface is reflected back into space, the remainder is absorbed by land masses and oceans, warming the earth’s surface and atmosphere. This warming process radiates energy, most of which passes through the atmosphere and back into space. However, small concentrations of greenhouse gases like water vapor and carbon dioxide convert some of this energy to heat and either absorb it or reflect it back to the earth’s surface (Christianson, 1999). It is this foundation that fuels ours cognitive notion of global warming and the concatenation of events that result in a global rise in temperature.
Global warming is a well known fact; however, there are many different speculations as to the causes. While there are those that like to believe that humans control the course of the global climate system, the truth is that there is also natural climate variability on a year to year basis (Kump, 2011). This variability results through natural cloud changes, which alter the amount of sunlight being absorbed by the planet (Spencer, 2010). There is more complexity to climate variability than sunlight and clouds. Our planet’s climate is dynamic and naturally varies on seasonal, decadal, centennial, and longer timescales. Each "up and down" fluctuation can lead to conditions which are warmer or colder, wetter or drier, more stormy or quiescent (Millar & Woolfenden, 1999). *
Perhaps the most well understood occurrence of climate variability is the naturally occurring phenomenon known as the El Niño-Southern Oscillation (ENSO), El Nino is a term coined by Peruvian fisherman to identify meteorological instability and ecological effects on fish and coastal life (Caviedes, 1984). This is an interaction between the ocean and the atmosphere over the tropical Pacific Ocean that has important consequences for weather around the globe. The ENSO cycle is characterized by coherent and strong variations in sea-surface temperatures, rainfall, air pressure, and atmospheric circulation across the equatorial Pacific. El Niño refers to the warm phase of the cycle, in which above-average sea-surface temperatures develop across the east-central tropical Pacific (Caviedes, 1984). These variables in our climate are due to the change in the amount of energy entering and escaping from the Earth.
The largest contributor in climatic forces comes in the form of short wave radiation from the Sun. Solar variability is major player in the distribution of energy throughout the Earth’s atmosphere. The changes in solar energy can be directly related to the Earth's orbital path, changes in the tilt angle of the Earth, or variations in the energy coming from the Sun. Also additional...
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