The Cause of Global Warming
Global warming is a term used in reference to the gradual rise in planet-wide temperatures, a fact that is now both documented and accepted by the scientific community. In June 2006, the U.S. National Research Council convened a panel whose deliberations revealed that the Earth was at its hottest in over 400 years. Studies further show that in the past century, there has been a global surface temperature 0.3-0.6°C increase in global temperatures in the past century (Seager, Naik and Vogel 3357). Again, this is by far the largest increase in average global temperatures in more than 1,000 years. Predictions by the scientific community show that in this century, there shall be an even higher increase in the average surface temperatures.
This form of global warming is mainly associated with the rise in greenhouse gases (chiefly methane and carbon dioxide) in the upper atmosphere of the earth’s surface, because of human activities that include industrial, farming, burning of fossil fuels, and deforestation activities (Maslin 58). At the same time, another school of thought of scientists on climate change and global warming maintain that natural causes art to blame for global warming. Accordingly, the premise of the current paper is to explore this controversy surrounding the issue of global warming, especially the role-played by humans in climate change and global warming general. On the other hand, the paper will argue that human activities have helped to accelerate the current global warming. On the other hand, the paper shall maintain that natural forces are to blame for the current global warming. These arguments will further form a basis for a conclusion of the paper.
It is hard for climate scientists to prove for a fact that the current global warming has not been caused by natural process. As such, it would be erroneous to affirm that human activities have been largely responsible for global warming. While human activities are largely linked to the current global warming, there is also evidence in existing literature to support the claim that natural causes could be the cause of the current global warming phenomenon.
To start with, glacier shrinkage began to rise around 1825, way before fossil fuels had any real effect on climate change (Ring et al. 406). This glacier shrinkage has maintained a steady slope increase, and not even the increase used of fossil fuels has had an effect on it. Addition ally, arctic air temperatures and solar activity have been shown to be correlated, as opposed to fossil fuels. In the same way, surface temperatures are correlated with solar activity. This is further evidence of the important role played by natural causes of global warming.
Secondly, global warming has also been attributed to solar variation. Solar variation is the changes in the level and amounts of radiant energy from the sun. The theory suggests that in the last sixty years the sun has gained so much strength than ever before (Haldar 10). The sun being the main source of energy and heat to the earth has increased temperatures on the earth’s atmosphere, oceans and lands. Scientist predict that a small change in the sun’s solar output has significant effects on the earth and as such, any changes in solar energy output leads to climatic changes specifically global warming.
The earth tilts on its axis around the sun in a year. The earth is said to be tilted at an angle of 23.5 degrees to the plane of the orbit. The four seasons are caused by the earth’s tilt. During summer, the northern hemisphere of the earth tilts towards the sun whereas in winter it tilts away from the sun (Shrivastava 7). The distance between the sun and the earth is said to vary since the orbit is elliptical, this changes the earth’s axis direction causing climatic changes such as global warming when the earth’s axis direction causes the earth to tilt nearer to the sun than usual therefore the summer season becomes extremely hot.
In addition to glacier shrinkage and solar variations and the earth’s tilt scientist suggest that natural occurrences such as volcanic eruptions also cause global warming. Volcanic eruptions release huge amounts of sulphur dioxide, dust, water vapor, and ash in the atmosphere causing atmosphere turbidity (Drake 120). Atmosphere turbidity is the measure of the levels of attenuation of the solar radiation by the atmosphere. The injection of ash and huge amounts of dust into the atmosphere increases the amount of particles in the atmosphere, its effect is not felt immediately, but the amount of gases released affects the climatic patterns for years to come (Shrivastava 6).
In the United States, there has been a decrease in the number of severe tornados over the past five decades, while the number of hurricanes has not risen in more than 10 years. A large number of climate scientists and/or meteorologists are opposed to the view that most of the current global warming is due to human action. They are of the view that for the most part, much of the current climate changes are as a result of natural causes. They contend that most of the observable changes are as a result of multi-century and multi-decadal changes taking place in the deep global ocean currents. Nonetheless, these changes have not been properly documented into the climate modelers’ thinking or global models. It is not in doubt that such natural causes as natural cycles, changes in the sun’s energy, and volcanoes, still have an impact on temperature today. In fact, natural cycle in cloud cover could be responsible for most of the earth’s warming, as evidenced by the PDO (Pacific Decadal Oscillation). Even as PDO is predominantly a geographic rearrangement in oceanic as well as atmospheric circulation patterns as reported in the North Pacific, nonetheless, these regional changes have also been shown to impact on weather patterns in far removed areas. While recent satellite measurements only span 7.5 years, they nonetheless, support the PDO as a key player in climate change and global warming.
While it is not in doubt that natural causes like changes in natural cycles and volcanoes continue to impact global temperatures, there is no doubt that human activities have had a huge impact on present-day global warming. Since the late 1800s, the earth’s surface temperature has been seen to incease. Scientists estimate that since then, it has risen by 0.74degrees Clecius, on average. Scientists further expect that by 2100, this average temperature shall have increased by an additional 1.8 to 4° C, in case the necessary steps are not taken.
The rise in greenhouse gases as a result of human activity is usually identified as a leading cause of global warming. Greenhouses gases are involved in the reabsorption of the heat reflected from the surface of the Earth, thereby heat in the earth’s atmosphere. This natural process is vital for life on the surface of the Earth. Nonetheless, increased human activities in the past few centuries have led to a rise, albeit temporarily, greenhouse gases concentration. Specifically, levels of methane and carbon dioxide have increased. The buildup of these gases hinders extra thermal radiation from leaving the surface of the earth, in effect trapping extra heat.
The main cause of this increase in the global average temperatures during this period has been the rapid increase in the rate of industrialization, as evidenced by the increased quantities of gasoline, coal, and oil burnt, as well as deforestation. These activities, among many more, have led to a rise in the levels of atmospheric greenhouse gases, especially methane, nitrous oxide, and carbon dioxide. These gases tend to occur naturally, and are vital for life on earth. However, in increasing and augmented quantities, they alter the climate, in addition to increasing the levels of global temperature.
The current global warming trend is anticipated to lead to extinctions. Numerous animal species and plants, already threatened by loss of habitat and pollution, are expected to have become extinct within the next century. While human beings may not be threatened with extinction, they are nonetheless, expected to face mounting challenges (Hardy 109). Recent severe floods, droughts, storms, for instance, seem to indicate that computer models forecasting increased ‘extreme weather events’ are spot on. Such increases are as a result of such human activities as land use and the burning of fossil fuels.
By trapping heat from the sun, man-made global warming leads to an increase in global atmospheric temperatures. The levels of such pollutants, and more so carbon dioxide, have been shown to rise significantly with the growth in the burning of forests, coal, natural gas, and oil (Haldar 138). During the same periods, there has also been a resultant increase in earth temperatures. Nearly all the regions of the Earth covered by ice are melting, even as sea levels rise. It is predicted that hurricanes will grow to become more destructive and stronger, even as their number is anticipated to reduce. Severity of floods in majority of the mid-continent regions has increased, even as droughts are getting deeper and longer. There has also been a disruption in the seasonal predictability of temperatures and rainfall.
The effects of global warming are very much alive today, as evidenced by rising sea levels as a result of melting of ice sheets and glaciers, and thermal expansion. In addition, the warming of the ocean surface has resulted in increased temperature stratification, while the number of tornadoes and hurricanes has become unpredictable and erratic. However, there appears to be a lack of consensus among scientists on the exact cause of global warming.
On the one hand, a group of scientists contends that human activities such as farming and burning of fossil fuels are the major causes of global warming, as global surface temperatures have increased significantly since the inception of the industrial revolution. On the other hand, another school of thought maintains that global warming is because of natural causes. In support of their claim, these scientists contend that glacier shrinkage started way before the burning of fossil fuels had any real impact on climate change. However, I am of the opinion that human activities have accelerated the rise in global temperatures more than natural causes have, but both processes are to blame.
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Maslin, Mark. Global Warming: Causes, Effects, and the Future (2nd edition). New
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Ring, Michael, Daniela, Linder, Emily, F. Cross and Michael E. Schlesinger. “Causes of
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