Global Warming - Coursework Example

Table of Contents 1Introduction 2 2Current understanding of global warming 3 3Carbon dioxide (CO2) and Global Warming 5 4Methane (CH4) and Global Warming 9 5Nitrous oxide (N2O) and Global Warming 11 6Other greenhouse gases 12 7Air Pollution and Global Warming 12 8Changes in sun’s energy 13 9Conclusion 13 Work cited 14 Name: Professor: Institution: Course: Global Warming 1 Introduction Towards the end of the 20th century and the better part of the 21st century, global climate change has occupied a prominent position in debate in the global arena as nations wake up to the reality of a rapidly changing world due to rising global population and negatively impactful human activity. The result of which is a warming globe that is changing life for organisms on the planet including humans (Biemann and Pattberg 17). This situation has been referred to as global warming which can be understood basically as a situation where the earth’s atmosphere has too much carbon dioxide than is required. Consequently the carbon dioxide acts as a blanket preventing heat from escaping from the earth’s surface thus warming the planet. When the sun rays reach the earth’s surface, the heat is absorbed. Most of the heat escapes back into the atmosphere only for some of it to be absorbed by the greenhouse gases including water vapour, Carbon dioxide and methane to prevent the earth from losing a lot of energy. If these gases increase in amount then the more heat they would absorb making the earth warmer than it should be. The gases play an important role since without them the earth temperatures will be very low. However in excess amounts, the gases can only cause more harm to the planet[Uni132]. In light of this reality, this paper hopes to exhaustively explore and give a detailed discussion on the main causes of global warming to shed more light on the topic under appropriate subheadings. 2 Current understanding of global warming According to scientists in Research by National Research Council of United Sates, global warming is one of the most difficult challenges our environment faces today. Global warming is caused by the green house effects where the earth’s heat trapping capability raises far from normal levels and this increased temperature causes a lot of problems and changes on the surface of our planet. As such global warming is a matter of concern for all the inhabitants of the planet earth irrespective of race, nationality or ideological differences. It is much a concern especially in the arctic region where glaciers and sea ice are retreating at a rapid rate. Islands are also facing the reality of reducing land mass as sea level rise to claim sections of the islands gradually. Extreme weather conditions such as flash floods, heat waves, and droughts should also be expected further casting a grim future of the human race and global flora and fauna collectively [Nat02]. Melting ice over the Antarctic and Arctic regions devastatingly changes the ecosystem meaning some species have to either change their mode of life or become extinct. Negative impact on our forests cover and the agricultural productivity are also some of the problems that are brought about by global warming (Vergano & Rice). According to the U.S. Environmental Protection Agency since 1975, the global surface temperature has risen by 0.5°C and this has taken the world’s temperature to its highest level in the past 1,000 years (Vergano & Rice). In the pre-industrialization era, climate change could have been explained by natural causes such as changes in solar intensity, earth’s crust activities such as volcanoes, and natural occurring such as population growth. However, today there are a multiplicity of factors that are not necessarily natural that are having quite a substantial impact on rising global temperatures. The main human activities being blamed for the excess carbon are believed to be burning of fossil fuels for energy to drive industrial processes, to drive vehicles and provide heat and electricity for our homes. The cutting down of trees is also another major contributor of excess carbon in the atmosphere since trees act as carbon dioxide sinks by absorbing carbon dioxide and releasing oxygen in the air (Milne and Grubnic 950). Scientists have spent decades researching on why global warming is occurring, they have looked at the events and natural cycles that are known to influence climate but the pattern and amount of warming that’s been measured cannot be explained by these factors alone without the inclusion of the effect of greenhouse gases (GHGs) emissions (Hardy 27) . To focus more on this, the United Nations formed a group of scientists known as “Intergovernmental Panel on Climate Change (IPCC)” to analyze the latest scientific findings and write a summarized report on what is causing global warming. The first thing that IPCC learned was that the greenhouse gases have a mean warming effect of about 33 °C (59 °F) (Black 5) .GHGs responsible for this warming, most come from the factories, combustion of fossil fuels in vehicles and electricity production. The most responsible gas for the warming is carbon dioxide (CO2) which causes 39-66%; methane (CH4) from agriculture and landfills especially from digestive systems of grazing animals, which cause 4-9%; and deforestation that would otherwise store CO2 ( Hansen, 74,75). Carbon dioxide is not the only gas having a profound impact on earth’s atmosphere; other gases such as methane and nitrous oxide are contributing massively into global warming. These gases come from poor waste management practices from agricultural fields and industrial areas. It is yet to be an irrefutable fact that global warming is actually caused by the greenhouse effect of these gasses but then there is general consensus amongst the scientists’ community that the 0.8 °C change in earth’s surface temperature that has occurred within 100 years since early 20th century was caused by the release of these gases[Uni135]. 3 Carbon dioxide (CO2) and Global Warming Carbon dioxide is the primary causative factor of global warming being a major green house gas. This gas is released and absorbed naturally through the carbon cycle involving plants and animals respiratory processes. Plants use carbon dioxide to produce energy and in the process release oxygen. Animals use oxygen and release carbon dioxide. This plays a pivotal part in balancing the amount of carbon dioxide in the atmosphere. Volcanic eruptions and natural decomposition of plants and animals also contribute towards regulating amounts of carbon dioxide in the environment. After the onset of the industrial revolution in 1750s, human activities such as burning of fossil fuels and changes in land use to accommodate cultivation of food crops at the expense of trees has contributed substantially towards release of excessive carbon dioxide thus causing a the destabilisation in the ecosystem[Uni135]. The amounts of carbon dioxide in the atmosphere have risen to such high amounts than can be absorbed by the existing carbon sinks. To make it even worse, degradation of forest cover is reducing the few remaining trees that are supposed to support the carbon cycle in conjunction with animals. The United Sates Environmental Protection Agency reports that atmospheric carbon dioxide concentration has increased by about 40% since 1750s (Pre-industrial period) the concentration towards the end of the 18th century was at 280 parts per million by volume (280 ppmv) but in 2010 it was at 360 ppmv. Even though volcanoes do contribute to the current state of affairs, human activity contributes more than 135 times the carbon that volcanoes produce yearly. Human activity produces a humongous 40 30 billion tonnes of carbon dioxide yearly. Now the existing carbon sinks can only absorb so much of this, leaving a lot of the gas to freely settle in the earth’s atmosphere where its effect is basically absorbing more heat disrupting the natural balance of life on the earth’s surface[Uni135]. When it comes to human activities, the biggest contributors to emission of carbon dioxide are: Electricity production- electricity is an essential source of energy for homes, businesses and institutions in the society today. Electricity consumption is particularly high amongst developed nations such as United States. Fossil fuels such as oil and coal are used to generate electricity to complement other sources such as geothermal power and hydroelectric power. Coal produces the highest amount of carbon dioxide even though it as a cheap fossil fuel[Uni135]. Transportation- road, rail and air transport is largely made possible by combustion of fossil fuels in engines to transport goods and people across distant places. In US alone it contributed to 31% of all greenhouse gases emissions[Nat02]. Industrial activity- many industries burn carbon fuels to power industrial activities and also use electricity to their activities. As a result a lot of emissions are also being blamed on factories especially in industrialized countries such as US, Germany and China. This source accounted for 14% emissions in US alone[Nat10]. Oil and coal are now the main sources of CO2 emissions. Coal is a source of potential large future emissions as its known resources are an order of magnitude greater than those of either oil or gas, it has declined in most part of the world but it has been increasing in China and United States. According to Black, CO2 emissions from burning fossils fuels have risen by for the last 20 years giving the earth much less chance to avoiding global warming (150). In 2011, emissions from burning fossils fuel increased by 5.9% bringing continues increase of CO2 since 1990, the baseline year for calculating emissions under the Kyoto protocol to 49% meaning an average rate of about 3.1% per year (UN Climate change Conference, 2011) . Professor Corinne Le Quere, director of the TCCCR at the University of East Anglia while attending UN climate talks in Durban, South Africa the stated that little had been achieved in the last two decades in fighting the risk from climate change."There have been efforts to use more renewable energy and improve energy efficiency but what this shows is that so far, the effects have been marginal," she said. "We need to do something about the 80% of energy that still comes from burning fossil fuels (UN Climate change Conference, 2011)." This sentiments we also echoed by professor Chris Rapley, professor of Climate science at University College London where he stated that “Human carbon emissions are certainly disturbing the climate system upon which we depend, and in spite of the economic slowdown, and despite all the efforts by governments, businesses and people to reduce them, our emissions are reaching new highs. The climatic consequences, already emerging, will grow over time, and are irreversible."A new level of decisive action is required now to achieve real emissions reductions. World leaders at the climate negotiations at Durban know the score; the opportunity to act consistent with their responsibilities and rank lies before them. We can only hope that they rise to the challenge (UN Climate change Conference, 2011)." According to the United Nations Environmental Programme (UNEP), the developing countries are going to increase carbon emission by up to 8 % if they purse the loopholes in their pledges. Many campaigners in Copenhagen climate summit had hoped that the carbon emissions would be reduced by at least 30-40% and be in a position to hold the temperature to 20C by the year 2020 (Vergano & Rice). However, this will not be possible if the rich countries are not ready to within the legal limits of the global climate deal that was negotiated in Bonn during the UN talks in June 2010. An analysis released by UN in June 2010 prepared by Bolivia indicated that the rich countries’ pledges could be converted into reduction targets as used in Kyoto protocol and when this is combined with carbon market mechanisms as well as calculations of loopholes, there is obviously a large gap between what the scientist have said is the needed cut (30-40%) and what the rich countries have pledged to cut so far. These calculations also indicate that if rich countries don’t use the loopholes, they will be in a position to reduce the carbon emission by at least 4-8% by the year 2017. However, if Bon proposal is adopted, they are likely to increase the emissions by 4-8% above the 1990 levels (Vergano & Rice). According to Hardy, the UN climate chief, the pledges that were tabled by the rich country were not enough to reach the 2C pledge which was made in Copenhagen and were not sufficient for the survival of the poor and the most vulnerable (172). In his speech, the UN climate chief also noted that with this trend, the greenhouse emissions would increase greatly in the next 10 years. In countries like Russia, their emission credits have accumulated to millions of tones as a result of collapse of the Soviet economy in the 1980’s (Hardy 176). This and other countries are seeking permission to be allowed to bank this credits and sell to other rich developed countries in the years to come. However, according to Stavchuk of National ecological Centre of Ukraine, selling credits to developed countries will not reduce the carbon emissions causing more global warming. 4 Methane (CH4) and Global Warming Methane is another notable contributor of global warming as it is in itself a greenhouse gas with the same effect as carbon dioxide. In fact methane has a high potential of absorbing more heat than carbon dioxide. The gas is found underground and it is a major component of natural gas, it’s a powerful trapping agent which contributes to global warming by holding infrared radiation near the earth surface[Kar09]. According to United sates Environmental Protection Agency the gas concentration in the earth’s atmosphere is more than it was in nearly 650,000 years back. Even though methane is a naturally occurring gas from the wetlands and arctic regions, this gas is also contributed through man-made functions. Methane is released from agricultural animal flatulence, rice paddies, landfills, and in the production and manufacturing of fossil fuels. This gas is 20 times more powerful in its ability of warming compared to carbon dioxide. For instance, a cow does an average release of between 70 and 120 kg of methane gas per year, the negative effect on the global warming is higher since about 100 kg of methane gas per year for each cow is equivalent to about 2,300 kg CO2 per year. The same amount of CO2 is produced by burning 1,000 litres of petrol. With a car using 8 litres of petrol per 100 km, one can drive 12'500 km per year i.e. 7'800 miles per year. There are about 1.5 billion bulls and cows world-wide emitting about 2 billion metric tons of carbon dioxide equivalents in a year (Hensen, 180). More over cleaning of rain and tropical forests to get more farm and grazing land is responsible for emitting about 2.8 billion metric tons of CO2 per year. According to the Food and Agriculture Organization of the United Nations (FAO) agriculture release 18% of the total emission of greenhouse gases around the world which is more than what is emitted by the transport sector. According to Henning Steinfeld, chief of FAO’s Livestock Information and Policy Branch, livestock are the most significant contributor in today's most serious environmental problems since livestock uses around 30% of the earth’s land surface and 33% of this land surface is used to producing feed for livestock. As forests are cleared to create new pastures which is a major driver of deforestation, mostly in Latin America where 70% of former forests in the Amazon have been turned over to grazing. Over 60% of total methane produced in the world can be attributed to human activity. This as mentioned before mainly comes form industrial, agricultural and waste disposal activities. Industrial activities include natural and petroleum gas systems where a lot of the gas gets into the atmosphere during the production, processing, storage and distribution processes. Agriculturally, domestic livestock such as cows release a lot of methane though natural digestive processes. Waste from homes and businesses also decompose in landfills to produce methane into the atmosphere. It is easier to manage the emission of methane into the atmosphere as most of the gas is produced through inefficiencies in humanly activities including improper waste disposal methods. 5 Nitrous oxide (N2O) and Global Warming Nitrogen oxide is also produced through both human and natural activities. The most common activities that produce nitrogen oxide are agricultural and natural biological activities. The concentration of the gas has increased by averagely 18% since the onset of the industrial revolution in late 18th century. Nitrogen oxide molecules stay in the atmosphere from approximately 120 years before being absorbed naturally or through chemical reactions. The gas is a hundred times more potent in terms of increasing global temperatures than carbon dioxide of the same amount. 40 % of the total global production of the gas can be blamed on human activities including industrial, transportation and agricultural activities. Agriculturally use of artificial fertilizer containing nitrogen is the major source of nitrogen oxide. Internal combustion of fossil fuel in vehicles produces the highest amount of nitrogen oxide associated with transport sources. Industrially the gas is a by-product of nitric acid production used in manufacturing of consumer synthetic products and chemical fertilizers[Uni134]. The nitrogen cycle is the main natural contributor of nitrogen oxide into the atmosphere. Agricultural sources remain to be the single largest contributors of nitrogen oxide into the atmosphere. The report by United Sates Environmental Protection Agency estimates that emissions of nitrogen into the atmosphere are expected to increase by at least 5% between 2010 and 2020 largely due to agricultural activities mainly in application of nitrogen-based fertilizers. This means the emissions can be controlled through such practices as responsible use of nitrogen-based fertilizers and use of organic farming practices where possible. 6 Other greenhouse gases Water vapour is the most abundant greenhouse gas but also has a short lifetime as it easily condenses and gets down to the earths surface as dew, snow or rain. Human activity has least effect on decrease or increase of water vapour into the atmosphere. Ozone (O3) is also another potent greenhouse gas which is also capable of causing damage to crops and respiratory problems to animals as an air pollutant [Uni132]. Chlorofluorocarbons (CFCs) hydro-chlorofluorocarbons (HCFCs), hydro-fluorocarbons (HFCs), per-fluorocarbons (PFCs), and sulfur hexafluoride (SF6) used in coolants, fire extinguishers and propellants have an impact on global warming too. They have a long lifetime and are capable of affecting climatic conditions for several years to come [Nat10]. 7 Air Pollution and Global Warming Air pollution is another contributor of global warming. There are different types of pollution which contribute to the atmosphere daily (Maslin, 201). It enters the atmosphere and behaves like methane by trapping the heat of the sun which exposes the earth to a warmer climate than naturally intended. This pollution comes from power plants, manufacturing plants and automobile emissions. This pollution occurs when the air contains fumes, dust, gases in dangerous amounts. The aerosols are a subset of air pollution that refers to the tiny particles suspended everywhere in our atmosphere, these particles can be both solid and liquid and are collectively referred to as ‘atmospheric aerosol particles (Maslin, 202). 8 Changes in sun’s energy The sun is the primary source of energy in form of heat to tihe earth. If the intensity of the sunrays reaching the earth increases then climate change is inevitable. In the past significant climate change in north America and Europe was attributed to reduced intensity of sun’s rays. This period is referred to as “the little ice age”. Recently though, the sun’s intensity cannot be cited as a significant causative factor since such intensity occurs only after a longer period of time possibly thousands of years. Satellites measuring sun’s energy received on the surface of the earth have shown the sun goes through 11 year cycles of high or lows but there has been no net increase in the energy received [Uni132]. 9 Conclusion In conclusion, green houses gases which include carbon dioxide, methane, air pollution; deforestation and nitric oxide are the major contributors of global warming in the Earth. However, these greenhouses gases have different heat-trapping abilities. Some of the gases can trap more heat than carbon dioxide. For instance, a molecule of methane emits 20 times the warming of a molecule of carbon dioxide. On the other hand, Nitrous oxide is 100 times more powerful than carbon dioxide. However, since their concentrations are lower than carbon dioxide because none of these gases contribute as much warmth to the atmosphere as carbon dioxide does. To understand the effects caused by all these gases altogether, scientists refers all greenhouse gases in the terms of equivalent amount of carbon dioxide. From 1990, these emissions have risen to about 6 billion metric tons yearly of “carbon dioxide equivalent” that’s why global warming is occurring at a high rate. Work cited Uni132: , (United States Environmental Protection Agency), Nat02: , (National Research Council ), Uni135: , (United States Environmental Protection Agency), Nat02: , (National Research Council ), Nat10: , (National Reseacrh Council ), Kar09: , (Karl, Jerry and Thomas), Uni134: , (United Sates Environmental Protection Agency ), Uni132: , (United States Environmental Protection Agency), Nat10: , (National Reseacrh Council ), Vergano D & Rice D, USA today: Climate change worsens extreme weather events . 20th November 2013 file:///C:/Users/research/Global%20warmimg/1.htm Read More