How Do Scientists Know That Humans Are Responsible for Climate Change - Literature review Example

Why is саrbоn diохidе соnsidеrеd роllutiоn and how do scientists know that humans are rеsроnsiblе for сlimаtе сhаngе? Discuss NAME PROFFESOR DATE Introduction Air pollution, is mainly caused by the emission of harmful gases to the environment as well as the mixture of gases in the atmosphere. Some of the gases which have been highlighted to be the main causes of air pollution are Volatile Organic Compounds (VOCs), Nitrous Oxide and Carbon Dioxide, among other gases produced during the combustion of metals. Despite getting a massive support as a leading cause of pollution, the question of whether carbon dioxide is a pollutant or not continues to spark debate amongst the environmentalists and scholars. This stems from the fact that it is a product of every living creature and it is essential for the plant survival. Some scholars take both sides of the argument. They agree that carbon dioxide is both a necessity and a pollutant. Epstein (2010) for instance argues that ‘some proportion of carbon dioxide is too much, some amount in safe and some amount is too little’. In this discussion, Carbon dioxide will be discussed as the main air pollutant that has adversely contributed to climate change. The discussion will revolve around why carbon dioxide is considered as a pollutant. In addition to this, human factors that have led to air pollution will also be discussed at length in order to have a better understanding of how human beings have contributed to climate change. As argued by Epstein (2010) it is true that carbon dioxide is safe when it is present in the environment in lower amounts. As a matter of fact, it is also a necessity for survival. The fact that carbon dioxide does not have direct impacts on respiration is the reason for its failure to be ranked a pollutant. CO2 has a direct effect on the environmental temperature (Jacobson, 2008). Recent studies have shown that CO2 emitted into the environment form slowly accumulates in the atmosphere further releasing some warming effects in weather sensitive areas such as the Arctic regions (EPA, 2015). The release of excessive CO2 into the environment has contributed to the rise of the greenhouse effect. As a result CO2 causes climate change in two ways; one way is through the absorption of energy in the atmosphere and the second way is decreasing the pressure in the air thus lowering the Earth’s albedo (EPA, 2015). Additionally, CO2 reacts with water forming carbonic rain or acid rain (Casiday & Frey, 1998). The compound dissociates giving hydrogen ions and hydrogen carbonate. Hydrogen ions lowers the PH of water in turn. Excess amounts of carbon dioxide in the atmosphere results to significant reduction of PH of water. For instance, some regions in the United States have decreased levels of PH which can be lower than 3.0 compared to the normal 7.0 level (Casiday & Frey, 1998). When water becomes acidic, it brings a lot of danger to the aquatic life (Casiday & Frey, 1998). In this case, excess amounts of carbon dioxide is a pollution. Human contribution towards global warming is a widely contested debate. Nonetheless, scientists have devised new strategies of proving the fact that humans are responsible for global warming. One basic way in which scientists is by tracking the changes in the amount of CO­2 in the environment within a period of time while comparing to the extent of development of human activities. Human activities have resulted to increase in carbon dioxide emissions to a level where it cannot be absorbed fully by the plants and the terrestrial biosphere. Statistical findings from Mauna Loa Observatory research centre, Hawaii indicate that the amount of CO2 has been steadily rising in the atmosphere since time immemorial. For instance, the 2013, 2014 and 2015 amounts of carbon dioxide in the atmosphere are 397.20, 399.00 and 401.30 parts per million (ppm) respectively (Earth System Research Laboratory, 2015). According to Hansen et al., (2008), the safest limit for CO2 in the atmosphere is 350 ppm. Since 1988, the amounts have exceeded this figure and has contributed to global warming. Fig 1: Earth System Research Laboratory, (2015) Much of the carbon dioxide released in the air is attributed to human activities as opposed to natural occurrences. This is because, industrial activities account for up to 94% of the Carbon dioxide released into the atmosphere. For instance, the use of automobiles burns at least 22% of fossil fuels. According to studies by Van De Wal et al. (2011) revealed that the transport sector plays a key role in the emission of carbon dioxide by accounting for 72% of carbon while shipping accounts for 14% while air transport accounts for 11%. Cutting down of trees 9% of the carbon emitted through this activity. Once human beings change the natural use of lands such as agriculture and cut down tree, for industrialization, it eliminates the absorption of carbon dioxide from the atmosphere by the plants through photosynthesis. Plants eliminate a substantial amount of carbon from the air, therefore if people participate in deforestation, this act increases the concentration of carbon dioxide in the environment which will eventually lead to climate change (Van De Wal et al. 2011). Besides this, scientists have proven that humans are responsible for climate change is by measuring carbon isotopes. Carbon comprises of three isotopes; 12C, 13C and 14C (Real Climate Organization, 2004). Carbon-12 (light carbon) is the most common isotope while carbon-13 and carbon-14 (heavy carbon) are less common. Carbon 12 and 13 are preferred by plants when compared to carbon-14 (Real Climate Organization, 2004). Fossil fuels originate from plants and therefore it is expected that they will have the same ratio of carbon-12 and 13. Isotope geochemists have analysed the presence of these carbon isotopes in plants by use tree rings (Real Climate Organization, 2004). Findings from research studies comparing the presence carbon-12 and 13 using tree rings have indicated that 12C and 13C have been decreasing for the past 10,000 years (Real Climate Organization, 2004; IPCC, 2007). Additionally, significant decrease in these two carbon isotopes was recorded in around 1850 AD when human activities increased tremendously. CO2 increase in the atmosphere results in reduction in 12C and 13 C isotopes. CO2­ ­increase is as a result of carbon emissions to the environment due to burning of fossil fuels. This is a clear proof that human activities are responsible for climate change. Besides the use of tree rings, research findings on the amount of carbon-12 and 13 isotopes present in carbon dioxide entrapped in the ice cores have indicated a decline. These findings supplements the tree ring findings as a proof of human responsibility in global warming. Human beings can protect the environment from pollution through adopting eco-friendly ways of doing this. For example, people can reduce the use of automobiles by cycling and walking or by means of public transportation, they can also use solar systems in place of electricity. This will ensure that the emission of CO2 reduces drastically as these two contribute the most percentage of carbon. Moreover human beings need to focus on conserving the environment and taking care of our forests and plants as they absorb CO2 which is another way of reducing the accumulation of carbon in the atmosphere. In conclusion, it is evident that carbon dioxide plays a substantial part when it comes to air pollution. The effects of carbon dioxide in the atmosphere is mainly attributed to the excessive heat it causes leading to warming. The amount of carbon dioxide in the air has greatly contributed to global warming therefore leading to climate change. Human beings act as catalyst in the process of climate change and air pollution. References United States Environmental Agency (EPA). (2015). Inventory of U.S. Greenhouse Gas Emissions and Sinkst: 1990-2013. [Online]. Accessed from: http://www.epa.gov/climatechange/Downloads/ghgemissions/US-GHG-Inventory-2015-Main-Text.pdf (Accessed from 22nd August 2015) Van De Wal, R. S. W., De Boer, B., Lourens, L. J., Kohler, P. and Bintanja, R. (2011). “Reconstruction of a Continuous high-resolution CO2 record over the past 20 million years.” Climate of the Past 7, no.4 Epstein, R. A. (2010). Carbon Dioxide: Our Newest Pollutant, Suffolk University Law Review 43(4): 797-828. Jacobson, M. Z. (2008). On the Casual Link between carbon dioxide and air pollution Mortality, Geophysical Research Letters, 35(L03809): 1-5. Casiday, R. & Frey, R. (1998). Acid rain: Inorganic Reactions Experiment. Washington University. [Online]. Accessed from: http://www.chemistry.wustl.edu/~edudev/LabTutorials/Water/FreshWater/acidrain.ht ml (Accessed on 24th August 2014) Intergovernmental Panel on Climate Change (IPCC). (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge: Cambridge University Press. Earth System Research Laboratory. (2015). Trends in Atmospheric Carbon Dioxide. [Online]. Retrieved from: http://www.esrl.noaa.gov/gmd/ccgg/trends/ (Accessed on 25th August 2015) Hansen, J., Sato, M., Kharecha, P., Beerling, D., Berner, R., Masson-Delmotte, V., ... & Zachos, J. C. (2008). Target atmospheric CO2: Where should humanity aim?. arXiv preprint arXiv:0804.1126. Real Climate Organization. (2004). Real Climate, Climate science from climate scientist: How do we know that recent CO2 increases are due to human activities? [Online]. Retrieved from: http://www.realclimate.org/index.php?p=87 (Accesed on 25th August 2015) Read More