Introduction
Human activities have been gaining significant attention in climate studies for they contribute to climate change, particularly global warming.
The prime cause of anthropogenic climate change is the release, into the atmosphere, of greenhouse gases such as carbon dioxide and chlorofluorocarbons by varied human activities. According to Rahmstorf (2008), exponential anthropogenic emission of greenhouse gases poses a severe threat to stability of earth’s climate. Subsequently, this threat affects humanity, flora, and fauna negatively (p. 35).
The major challenge that climatologists are grappling with is global warming, which is the main cause of climate change across the world. Since anthropogenic climate change occurs due to the cumulative effect of greenhouse gases, it requires both immediate and long term attention because its consequences are particularly grave and irreversible. Thus, various stakeholders need to consider having both short and long-term intervention measures aimed at reducing levels of greenhouse gases and mitigating their impacts on climate.
Scientific Debate
Since anthropogenic climate change occurs due to the cumulative effect of greenhouse gases, it is imperative that climatologists focus on both immediate and long term interventions to avert future crises of global warming that seem to threaten the existence of humanity and other forms of life on earth.
Scientific debate has been raging as to whether global warming is a natural occurrence or an anthropogenic consequence, but there is indisputable evidence that temperature of the earth has been continually rising for centuries. Rahmstorf (2008) argues that climatologists expect that by the 22nd century, temperature of the earth will rise by 5 oC or more globally, while regionally, it will be more than 10 oC (p.36).
Given the current trends of human activities, the rise of temperature will continue for more centuries to come if immediate and long term interventions are not put in place to regulate the anthropogenic emissions of greenhouse gases. The fact that temperature of the earth has been increasing for centuries clearly indicates that anthropogenic emissions of greenhouse gases are responsible for climatic change, which seems to threaten the existence of life on earth.
Immediate and long-term interventions are essential in reducing anthropogenic emission of greenhouse gases, because climatic crises due to global warming have grave impacts on the existence of life.
The increase in levels of greenhouse gases in the atmosphere indicates that, global warming is real and is gradually becoming worse each day if necessary interventions are not put in place to reverse the trends. Although greenhouse gases are many in the atmosphere, carbon dioxide contributes considerably to climate change because of its abundance in the atmosphere and sources of emissions.
Rahmstorf (2008) argues that, preindustrial levels of carbon dioxide were about 280 parts per million (ppm), but the current level of carbon dioxide is over 380 ppm (p.36). It, therefore, means that increasing the levels of carbon dioxide in the atmosphere is the cause of global warming. Hence, both immediate and long term interventions are critical in reducing emission of carbon dioxide into the atmosphere by human activities.
Climatologists hold that, with the current trends of anthropogenic emission of carbon dioxide, it is predictable that by the 22nd century, the levels will be about 1000 ppm. The Intergovernmental Panel on Climate Change (IPCC) considers carbon dioxide levels of between 400 to 600 ppm to be particularly dangerous.
Surprisingly, currents levels of carbon dioxide stand at about 380 ppm, while levels of total greenhouse gases are about 450 ppm. Furthermore, there has been increased emission of greenhouse gases recently because virtually all countries across the world rely on fossil fuel as the source of their energy. Such trends are quite alarming because it depict that anthropogenic greenhouse gases are responsible for global warming and subsequent climate change.
According to Erin (2011), most countries have ratified the United Nation’s recommendation of steadying greenhouse gases in the atmosphere and reducing anthropogenic interference (Para.9). Thus, to avert climate change, immediate and long term measures such as developing and relying on renewable sources of energy is imperative.
Although greenhouse gases come from various sources, carbon dioxide emissions are mainly due to anthropogenic sources. It is currently evident that the main cause of drastic increase in carbon dioxide levels is due to increased utilization of fossil fuel.
Given that the amount of fossil fuel used correlates with the amount of carbon dioxide emitted into the atmosphere, Rahmstorf (2008) reasons that, the apparent increase in carbon dioxide levels form about 57% of total emissions because ocean and biosphere, which acts as carbon sinks, have absorbed approximately 43% (p.36).
This means that, had it not been for the carbon sinks, which absorb a significant percentage of carbon dioxide, there would be a high percentage of carbon dioxide in the atmosphere, which consequently could have caused severe climate changes due to global warming. It is estimated that oceans alone have absorbed approximately 30% of anthropogenic emissions making marine environment become acidic.
Therefore, anthropogenic emission of carbon dioxide does not only cause global warming but also acidify marine environment, thus threatens the existence of marine life. Hence, both immediate and long term interventions are essential in reducing anthropogenic emission of carbon dioxide.
The Opposing Views
Opponents of anthropologic climate change argue that global warming is a natural process that does not need any immediate or long term intervention. Despite the fact that greenhouse gases are the main cause of climate change and global warming, Patterson argues that global warming is a myth because some scientists refute the claim that human activities are responsible (Para.2).
The scientists view that natural processes mainly contribute to accumulation of greenhouse gases in the atmosphere. Among greenhouse gases, carbon dioxide is one of the gases that form significantly larger percentage of volume in the atmosphere and thus is the main cause of global warming that has been occurring for centuries.
However, a recent study indicates that temperature increase has stagnated in spite of increase in the use of fossil fuel across the world. Kaufmann, Kauppi, Mann, and Stock (2011) argue that, between 1998 and 2008, there was negligible increase in temperature and decline in surface temperature by 0.2 oC in years between 2005 and 2008, yet their anthropogenic emission of carbon dioxide increased tremendously (p.1).
Inconsistency in the amount of carbon dioxide emitted and increase in temperature beg a question as what is the real cause of global warming. Disconnect between emission of carbon dioxide and global warming implies that there may be other factors apart from carbon dioxide that contribute to global warming.
Increasing concentration of carbon dioxide in the atmosphere and fluctuating temperature increase indicates that there are other confounding factors that significantly influence global warming. More study carried by Kaufmann, Kauppi, Mann, and Stock (2011) shows that, in the year 2000, water vapor decreased by 10% in the stratosphere and slowed temperature increase by 25%, contrary to expectations of what would have occurred because of high concentration of greenhouse gases (p.2).
Expectations were that global temperature would have risen due to decrease in water vapor because they absorb latent heat of vaporization and bring about cooling effect on the surface of the earth. However, abnormal decrease in temperature in spite of exponential increase in anthropogenic emission of greenhouse gases tends to disapprove that human activities are the leading causes of global warming.
Critics of anthropogenic climate change argue that, parameters that scientists use to measure the number of greenhouse gases in the atmosphere and increase in temperature are not reliable since they are subject to many confounding factors.
Rahmstorf (2008) asserts that, temperature measurement originated from proxy data such as tree rings, corals and ice cores that have a link with local temperatures and other parameters that influence real temperature variation (p.45). Local and regional temperatures can be significantly higher than global temperatures because of variation in causes that may not necessarily reflect global warming.
Moreover, critics argue that the use of satellites in measuring temperature of the earth through radiations is unreliable since it is subject to atmospheric radiations of the sun. Short life span of satellites also affects the accuracy of data collected due to variation daily temperature and calibration of satellites. Thus, temperature of the earth is fairly constant and subject to other environmental factors other than anthropogenic emission of greenhouse gases.
Supporting Views
Climate change mainly results from human activities that emit greenhouse gases into the atmosphere. Greenhouse gases accumulate in the atmosphere and create the greenhouse effect that shields radiations from the earth surface from escaping into the atmosphere, thus increases the temperature of the earth.
Therefore, the argument that global warming is a natural process of the earth does not give sufficient evidence since it only presumes that temperature is a variable factor that varies from one place to another and from one year to another.
Moreover, critics of anthropogenic argues that despite an increase in the use of fossil fuel and the temperature of the earth remained relatively constant and dispute that human activities are the cause of global warming. According to Kaufmann, Kauppi, Mann, and Stock (2011), apparent increase in global temperature for the last 50 years is due to a measurable increase in anthropogenic emission of greenhouse gases (p.3).
There was insignificant rise in global temperature between 1998 and 2008 because sulfur emissions brought about cooling effect, which cancelled out warming effect of greenhouse gases. Therefore, although anthropogenic emission of greenhouse gases causes global warming, there are other factors that mediate occurrence of global warming in the universe.
Increasing concentration of carbon dioxide and other greenhouse gases are the cause of global warming. Given that human activities emit a lot of carbon dioxide into the atmosphere, they contribute significantly to the occurrence of global warming.
Therefore, anthropogenic emission of carbon dioxide is easily quantifiable because the amount of fossil fuels used correlates directly with the amount of carbon dioxide in the atmosphere. During the preindustrial period, carbon dioxide concentration in the atmosphere was about 280 ppm, but currently, the concentration is about 380 ppm.
Plausible explanation for the huge increase in concentration of carbon dioxide in the atmosphere is an anthropogenic emission, which occurred due to industrialization. Industrialization led to increased consumption of fossil fuel and concomitant emission of carbon dioxide.
Rahmstorf (2008) contends that the total amount of carbon dioxide emission that is in the atmosphere forms about 57% of the emissions because oceans and biosphere absorbs about 43% (p.37). Hence, if it were not for oceans and biosphere to absorb about 43% of carbon dioxide, global warming would have caused drastic climatic changes that threaten the existence of life on earth.
Although critics of anthropogenic climate change argue that parameters of measuring global warming are unreliable, climatologists have used numerous parameters and models to enhance consistency of data collected.
Since there is significant disparity in temperature at local and global levels, consistency of variability is quite evident to suggest that anthropogenic activities in certain places relates with temperature of specific locations. Thus, proxy data collected from tree rings, corals and ice cores give an overall picture of occurrence of global warming.
Critics further assert that satellites are not reliable in measuring due to prevalence of confounding variables and short life span of satellites. However, Rahmstorf (2008) argues that, satellite has effectively shown that since 1979 to present, about 20% of Arctic sea ice cover has shrunk due global warming, which makes it melt (p.44). Hence, melting of ice and rising sea levels are indisputable effects of global warming that occur due to anthropogenic emission of greenhouse gases.
Conclusion
For centuries, there has been a raging debate as to whether global warming results from natural or anthropogenic processes. Numerous studies support that anthropogenic emission of greenhouse gases like carbon dioxide, chlorofluorocarbon, water vapor, methane and others causes global warming and subsequent climate change, thus threatening the existence of life on earth.
Increasing concentration of these gases in the atmosphere correlates with global warming, meaning that human activities are responsible for climate change that is threatening humanity and other forms of life on earth. Therefore, since anthropogenic climate change occurs due to the cumulative effect of greenhouse gases, it requires both immediate and long term attention to avert grave consequences of global warming.
References
Erin, S. (2011). Canberra Times: The future is Lean and Green. Financial Times Limited. Web.
Kaufmann, R., Kauppi, H., Mann, H., & Stock, J. (2011). Reconciling Anthropogenic Climate Change with Observed Temperature 1998-2008. Proceedings of the National Academy of Sciences, 1-4.
Patterson, R. (2011). Human Caused Warming. Deseret News Publishing Company. Web.
Rahmstorf, S. (2008). Anthropogenic Climate Change: Revisiting the Facts. Potsdam Institute for Climate Impact Research, 34-53.