GlobalWarming: Causes and Mitigation
GlobalWarming: Causes and Mitigation
Theincrease in human activities in the past 200 years has given rise tothe atmospheric concentrations of many gases primarily carbon dioxidethat is associated with global warming. These gases trap thermalenergy leading to the greenhouse effect, and thus are collectivelytermed as greenhouse gases (GHGs) (Collins etal.,2007). The greenhouse effect is responsible for the global warming,that is in turn believed to cause climate change. Climate change ischaracterized by the ever-changing weather patterns that threatenfood production and the very existence of human beings. In addition,climate change is characterized by the imminent risk of catastrophicflooding as sea levels continue to increase. The impacts of globalwarming are especially disastrous to the vulnerable in poorcountries. This is because of their high dependence on naturalresources and limited potential to adapt to the climate variabilityand extreme conditions associated with climate change (Collins etal.,2007).
Globalwarming and climate change remain a popular and controversial topic(Huang etal.,2012). The sources of GHGs may be through human activity(anthropogenic) or natural causes. Human activity may be responsiblefor the rapid increase in GHGs since gases such as halocarbons haveno known natural sources. For other GHGs, such as CO2,human activity may be traced according to their geographicaldistributions with high concentrations of these GHGs gases occurringover land in highly populated areas. Analysis of isotopes also helpsin distinguishing sources of GHGs for instance, CO2fromcombustion of fuels. Radioactive forcing is used to determine thelikelihood of the concentration of the GHGs to cause global warming.Positive radioactive forcing is responsible for the elevation ofglobal temperatures, whereas negative radioactive forcing isassociated with global cooling.
Naturalcauses of global warming include solar activity and episodic largevolcanic eruptions. Solar activity is believed to cause globalwarming by increases in solar irradiance, which leads to the overallincrease in atmospheric CO2and CH4concentrations. The increased solar irradiance decreases the abilityof the oceans to absorb atmospheric gases. In addition, increasedsolar activity has the end result of increasing the naturalproduction of GHGs such as methane and carbon dioxide as the processof decomposition of organic matter and out gassing in permafrost isspeeded up (Idso and Singer, 2009).
Theanthropogenic emissions of GHGs are partially responsible for theelevation of global temperatures (Kaufmann etal.,2011). Greenhouse gases such as CO2absorb heat in the form of infrared radiation emitted from theearth’s surface leading to elevation of global temperatures. Sincethe industrial revolution the atmospheric CO2concentrationhas soared to about 40% leading to ocean warming, rise in sea leveland melting of the arctic sea ice. This increase in atmosphericcarbon dioxide is attributed to the combustion of fossil fuels, whichhas low fractions of 13C and 14C isotopes. The other anthropogeniccause of global warming is deforestation that disturbs the balance ofthe carbon cycle. The natural processes that restore this balance areslow compared to the human-induced causes of carbon dioxide leadingto a build-up of GHGs.
Solaroutput as a direct cause of climate change has not contributedsignificantly to global warming. This is because in the 11-year solarcycle over the past century, the sun output has not varied more than0.1% to dominate global warming (Lockwood, 2009). Instead,anthropogenic factors have been the dominant contributors to globalwarming as illustrated in figure 1.In the past, a large proportion of GHGs emanated from ice cores butin recent times, these GHGs are attributed to human-induced factor.
Figure1: An illustration of the natural and anthropogenic factors thatcause global warming. Positive forcing factors are responsible forthe elevation of global temperatures and negative forcing result incooling (Collins etal.,2007).
Humaninfluences on climatechangehave been an extremely complicated discourse. There are well-focusedobjections to the mainstream consensus on human-induced drivers ofclimate change. This analysis is of the viewpoint that climate changeis mainly attributed to anthropogenic factors since global GHGssoared significantly due to the continued reliance in the combustionof fossils fuels since the start of industrial revolutions this hasbeen accounted in several studies discussed here. The discourse onclimate change being as a result of anthropogenic factors is centeredon the uncertainties of the measurement of the exact influences ofthese factors on global warming and climate change.
Climatemitigation measures include efforts that are geared towards theprevention or reduction of the net release of GHGs into theatmosphere. It encompasses the use of renewable such as solar andwind energy as well as the adoption of efficient technologies thatare energy efficient. In order to mitigate climate change, twoagreements have been adopted, i.e. the United Nation FrameworkConvention on Climate Change in 1992 (UNFCCC) and the Kyoto protocol,1997. The UNFCCC provides a mechanism for international cooperationin climate mitigation whereas the Kyoto protocol, which came intoforce in 2005, is aimed at setting legally binding emission caps fordeveloped countries.
Climatechange can be addressed by geoengineering where there is anintentional modification of the earth systems. Such modificationefforts include carbon dioxide removal, solar radiation management,and direct capture and removal of CO2fromthe atmosphere (Shepherd, 2009). Land-use practices such asafforestation and reforestation help to offset the imbalances in thecarbon cycle by removing additional CO2from the atmosphere (Shepherd, 2009). Solar radiation managementincludes measures that are geared towards reflecting the percentageof sunlight back to space to minimize global warming.
TheEuropean Union has set measures to curb emissions of GHGs by passingbinding legislation to reduce emissions by 20% of the 1990 levels(European Union, 2014). These measures are implemented in acap-and-trade system with emphasizes on the adoption renewable energysources such as wind and solar. In addition, the backbone of EUclimate change policy has been the ambitious EU emissions tradingsystem (EU ETS) in 2005 that aims at lowering carbon emissions andadopting clean technology.
Carbontaxing as a method of slowing global warming, and thus climate changemitigation has been deployed domestically and regionally. The successof carbon taxing regimes in mitigating global warming is anchored ontheir overall cost and economic variability. In addition, carbontaxing should provide incentives for clean technologies developmentand implementation (Aldy etal.,2008). Carbon taxing is especially applicable for developingcountries that may have a limited institutional capacity for acap-and-trade system such as the EU ETS system.
Recommendedpolicy changes to stabilize global climate change
Therealization of cuts in the GHGs and mitigation of climate change willrequire the cooperation of all countries and all sectors of theeconomy given that the impacts are potentially disastrous to all. Thepolicy to curb global emissions should be economically viable andtenable for a long time to stabilize global climate. Internationalagreements that are inclusive of all countries should be set upframeworks that combine emissions permits and carbon tax at anational level. In addition, developing countries should be providedwith incentives to enforce such agreements that may weigh down ontheir economic development.
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Lockwood,M. (2009). Solar change and climate: an update in the light of thecurrent exceptional solar minimum. Proc.R. Soc. A.,466, 303–329.
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