Introduction
According to Burroughs (2), Climate change is defined the alteration of the weather patterns of a particular place over a long period of time. This alteration can be traced by measuring the weather phenomenon under parameters such as temperature, precipitation and wind patterns.
This climate change can only be proven by comparing the climatic conditions of a particular place in two or more different times. These changes are as a result of the changes in the factors which determine the amount of sunlight that gets to the earth surface. Additionally, they also result from changes in factors which determine the amount of sun energy which is given up by the earth surface.
Another aspect which is considered as climatic change is the wide variability in the weather conditions of a particular place, notwithstanding the fact that the average weather conditions remains constant. To qualify as an aspect of climatic change, the variations in weather condition must be studied over a period of time. This is because climatic change is understood as a pattern of weather change over a long period of time.
The main facts of how the climate is changing
The climate change has been a continuous trend on earth for many years. According to Beniston (128), it has been documented that the global sea level has risen by about 170mm over a period of 100 years. It is estimated that this rate is likely to double with time if the current trend remains.
Additionally, the temperature on earth has risen in recent times by higher rates than was previously experienced. This increase has been witnessed since 1970s and this trend projected to continue for the next 20 years. Research has established that, the global temperature is expected to increase with time and this might have serious catastrophic effects.
In addition, this increase in temperature has been responsible for the warming of the oceans. It has been said that, the oceans have absorbed the sun energy causing an increase in temperature of the oceans waters for up to 700 meters. The sunrays, when they come across a surface, produce heat as they reflect back. This is why the sun is believed to heat the atmosphere from the ground. That is why the ocean water temperatures tend to raise when struck by sun energy.
Another evidence of climatic change is the decline in the mass of ice sheets in Greenland and Antarctic. Between 2002 and 2006, Greenland lost about 150 cubic kilometers of ice sheet every year. During the same period, Antarctic lost about the same amount of ice sheet. Research has also established that there has been a decline in the amount of sea ice in the arctic over time due to the increase in the temperature over the earth.
The glaciers are also declining in such places as the Alps, the Himalayas, Rockies and Andes. Another compelling evidence of climatic change is the wide variation in temperature in the United States over the last few decades. This has been coupled with unexpected intensity in the amount of rainfall over the same period. It has been documented that, the carbon dioxide which is emitted in the atmosphere ends up contaminating the oceans since it cause an increase in the acidity of the ocean waters.
The history of climate changes over various timescales
It is estimated that, 4 billion years ago, the sun emitted less amount of sun energy implying that the earth’s temperature at that time was very low. The implication for this is that water could not have existed in the liquid state in most parts of the world as it is today.
However, water existed in liquid state partly due to the presence of green house gases which could have increased the temperatures of the earth to level similar to what we have today. Another possible contributor of the high temperatures is the lower reflectivity of the earth due to smaller continents which existed at that time.
About 3 to 5 million years ago, during the Pliocene age, the temperature of the world was as warm as it is now. The concentration of carbon dioxide as at that time was about 30% higher compared to today’s level. It is also estimated that the sea levels were about 15 meters higher than today’s level and the temperatures were way hotter than they are today.
It is believed that during this age, the earth must have been a perpetual state of El Niño. This El Niño state, usually result to very high temperatures or very high precipitation levels across the surface of the earth. In this permanent El Nino state, the temperature across the pacific remained constant.
However, a subject that generates a lot of speculation is the emergence of glaciations during the end of the Pliocene age. This phenomenon is attributable to the reduction in the amount of carbon dioxide in the atmosphere, which lowered the temperature on the earth’s surface. Additionally, glaciations are attributed to the closing of the Panama Isthmus, which caused a much freer circulation of ocean waters. This circulation is believed to have led to the formation of ice sheet.
Causes of climate change
Natural causes
According to Ahrens (388), some of the natural causes of climatic changes include ocean currents, volcanic eruptions, earth orbital changes and solar variations. Volcanic eruptions are believed to release gases such as sulphur dioxide, ash, dust and water vapor. These emissions have the potential to cause alteration in climatic conditions of the earth by increasing the reflectivity of the sun energy in the atmosphere. This causes the cooling of the earth’s surface due to the reflected sun energy.
Additionally, the ocean currents contribute to climatic change by transferring a large amount of sun energy over long distances. The winds contribute to this transfer of energy by blowing across ocean currents and thereby causing variation in the climatic conditions in a place. The ocean current also determines the concentration of carbon dioxide in the atmosphere.
It is also known that the earth is tilted at an angle of 23.5o to the perpendicular plane of its orbit. This movement has the effect of accentuating the tilt or even of reducing it considerably. A more pronounced tilt is responsible for warmer summers and colder winters. In contrast, less tilting is responsible for cooler summers and warmer winters.
In as much as the sun is perceived to give out a constant amount of sun energy, the amount of sun energy output increases over time though gradually. These changes in the output of sun energy may cause climatic changes on the earth. It worth noting that, the reason why the temperatures across the surface of the earth has been rising is due to these changes in the output of the sun energy.
However, it cannot be concluded that the variation in sun energy has played a major role in the global climatic changes. Mostly, these climatic changes have been caused, to a great extent, by the global warming.
Human causes
During the industrial revolution, most industries resorted to using fossils fuels for their energy requirements. These fossil fuels release carbon dioxide during combustion which is one of the green house gases. Those industries are also major contributors of methane and nitrous oxide in the atmosphere.
Other activities which have contributed to the increase in the amount of carbon dioxide in the atmosphere include deforestation, clearing of land and agriculture due to the usage of machines which consume fossil fuels.
The rearing of animals is a major contributor of methane gas in the atmosphere. Methane is also released during the process of coal mining, leakages of gas pipes and the process of landfills.
Green house effects
The emission of green house gases, mainly due to human activities, destroys the ozone layer which acts as a shield against the harmful rays of the sun. This ozone layer regulates the amount of sun energy which gets to the surface of the earth. This unregulated sun energy increases the general temperature of the earth thus causing climatic changes.
How the global climate will change in the future
The trend of change in the global climate has been observed as a continuous process. The global climate change, especially with the current human activities, is expected to change to worse if the current trend goes uninterrupted. There has been increased emission of harmful gases into the atmosphere from the human activities. The amount of green house gases is projected to increase in future due to the increase in industries as well as vehicles which consumes fossil fuels.
This increase might have adverse effects in the atmosphere. For instance, it might lead to increase in the temperature of the earth in the long run. The other possible effect is the variation in the amount and patterns of precipitation which is experienced on earth.
Additionally, there will be a reduction in the amount of ice and snow cover, as well as a reduction in the amount of permafrost. Another possibility of global warming will be the rise in the sea levels with time. The green house gases are likely to increase the acidity of ocean water that affecting the life of organisms living in the oceans.
However, the changes in climatic conditions will depend on a number of factors like, the rate at which the green house gases will continue to be emitted, the magnitude of the natural causes which are likely to have a profound effect on the climatic conditions and the responsiveness of weather patterns to the effects of the green house gases (Eileen Claussen, Vicki Cochran,Debra Davis 1).
The implication of the preceding arguments is that, there is need to look into those activities which emit green house gases with a view of curbing them. This is informed by the fact that the contribution of the human activities in causing climatic changes is higher than the contribution of the natural causes.
Works Cited
Ahrens, Donald. Essentials of Meteorology: An Invitation to the Atmosphere. Belmont: Cengage Learning , 2012. Print.
Beniston, Martin. Climatic Change and Its Impacts: An Overview Focusing on Switzerland. Dordrecht: Kluwer Academic Publishers, 2004. Print.
Burroughs, William. Climate Change: A Multidisciplinary Approach. New York: Cambridge University Press, 2007. Print.
Eileen Claussen, Vicki Cochran,Debra Davis. Climate change: science, strategies, & solutions. Arlington: BRILL, 2001. Print.