Global Warming Is Anthropogenic - Essay Example

Global Warming is Anthropogenic Institute The issue of Global Warming is very much in the limelight of contemporary public discourse. Global Warming is real, it is anthropogenic (man-made), it results in disastrous consequences and it needs to be addressed urgently. Scientific evidence unequivocally supports the reality of Global Warming and demonstrates that human activity is the cause of rising atmospheric temperatures, due to greenhouse gas emissions. Global Warming poses great risks. There are various adaptation and mitigation responses which can combat the threat of Global Warming. Global Warming is Anthropogenic. The issue of Global Warming is very much in the limelight of contemporary public discourse. It has emerged as a factor which shapes a nation’s environmental and political policy. It is an important aspect of climate change. Global Warming is defined as the recent documented increase in the mean surface temperature of the earth (Environmental Protection Agency, 2012). This increase is largely due to the Greenhouse Effect. The concept of the natural Greenhouse Effect was first postulated by atmospheric scientists in the early nineteenth century, beginning with Joseph Fourier. The earth’s atmosphere functions like the glass pane of a greenhouse. It permits short wave, visible solar radiation to reach the earth. The invisible infrared and ultraviolet radiation are absorbed and scattered by the atmosphere. The visible light is absorbed by the earth and transformed into heat. This heat is then re-radiated as invisible infrared radiation. A significant percentage of this radiation, which is reflected back by the earth and ocean, is trapped by the greenhouse gases in the atmosphere. These gases absorb this energy and radiate warmth back on the earth’s surface. Due to these gases the atmosphere constitutes a blanket which warms the earth, raising the surface temperature by about 33o C. (Weart, 2011). The molecules in the atmosphere which absorb and re-radiate the heat are called ‘greenhouse gases’ because they hold in heat like the glass walls of a greenhouse. In the absence of these gases, the earth’s night temperature would fall below zero degrees. The major greenhouse gases in the atmosphere are carbon dioxide, methane and nitrous oxide, along with water vapor. This natural greenhouse effect has been exacerbated since the Industrial Revolution by human activity, which has contributed to the marked increase of heat-trapping gases in the atmosphere. This growing concentration of ‘greenhouse gases’ in the atmosphere is the cause of Global Warming. Governments, organizations and individuals realize the significance of Global Warming as a factor in preserving life as we know it on earth. Global Warming is real, it is anthropogenic (man-made), it results in disastrous consequences and needs to be addressed urgently. In spite of some skeptics who refuse to accept the truth of Global Warming, an almost universal consensus has been reached on its reality. One argument advanced by skeptics is that there is no abnormal rise in the earth’s surface temperature. This is refuted by scientific records of temperatures which show that “The average global temperatures during the 1980’s exceeded that of any other decade since reliable temperature recordings began a century ago” (Bongaarts, 1992, 299). The United Nations’ Intergovernmental Panel on Climate Change (IPCC), constituted of reputed scientists from 113 countries, states in its report of February 2007 that “Warming of the climate system is unequivocal” (IPCC, 2007, 30), and cites irrefutable, scientifically documented proof or the widespread increases observed in global average air and ocean temperatures. In the last fifty years of the twentieth century, hot days and nights have become more frequent over land areas. There is an increased occurrence of extreme weather conditions, such as heat waves, extreme precipitation, extremely high sea levels, tropical cyclonic activity, hurricanes and droughts. There is a rapid melting of glaciers and sea ice in the Arctic and the Antarctic – leading to rising sea levels and coastal flooding. There is an average increase of 3.1 mm/year in the global sea level since 1993. This is due to the melting of glaciers, ice sheets and the polar ice caps. There is an observed decline in the extent of Arctic sea ice, mountain glaciers and snow cover. Areas under drought conditions have increased. To clinch the evidence of rising temperatures, the IPCC report states that the “Average Northern Hemisphere temperatures during the second half of the 20th century were --- the highest in at least the past 1300 years” (IPCC, 2007, 30). This rise in temperature is further proved by the pronounced changes in natural systems. These include an increase in the number and size of glacial lakes, ground instability in permafrost terrains, and changes in the polar ecosystems. Rising temperatures are also demonstrated by changes in seasonal events, such as the early greening of flora, egg-laying and bird migration, and the spread of tropical diseases, like dengue, due to increased warm ranges for mosquitoes and other vectors. There is bleaching and disintegration of coral reefs, due to rises in the surface temperature of the oceans and the acidification of the water. Scientifically documented changes in wind patterns, decreases in snow cover, thickness of ice, length of freezing seasons, extent of permafrost and increase in soil temperature all provide clinching evidence that Global Warming is unequivocally real. (IPCC, 2007, 30). Within the framework of science, even as research continues, the scientific consensus is that Global Warming is virtually certain and is demonstrated by incontrovertible scientific evidence. The cause of Global Warming is anthropogenic. However, dissidents argue that even if Global Warming is real, it is due to natural causes. Solar radiation and sunspot activity are cited as the major causes of temperature increases. Scientists concede that there is evidence of a very small correlation between sea-surface temperature and the eleven-year solar cycle in past centuries. This tiny correlation does not hold out after 1960, when the effect of greenhouse gases began to be felt. Studies show that while sunspot activity and cosmic rays decreased after 1950, global temperatures continued to accelerate “at a record-breaking pace, chalking up a total of 0.8°C of warming since the late 19th century” (Weart, 2011). This finding effectively demolishes the argument that solar activity is responsible for the rising temperatures seen since the 1960’s. Even those scientists who hold that solar activity influences climate agree that while changes in solar output have slightly increased global average temperatures since the beginning of the Industrial Revolution, the planet-warming effect of man-made greenhouse gases is about 20 times greater. At the most, solar activity cannot be held responsible for more than 30% of global warming since 1970. Solar influence on rising temperatures pales into insignificance when compared to the effect of greenhouses gases. “By the end of the twenty-first century, the total temperature increase attributable to man’s actions is expected to exceed 4 0C above pre-industrial levels”(Bongaarts, 1992, 302). Scientists are unanimous in conceding that the earth is extremely sensitive to the slightest changes in solar radiation reaching the earth. In this context, it is clear that any interference by greenhouse gases to solar radiation in the atmosphere poses a major risk to the climate system. Precise satellite measurements over the past thirty years shows that while the sun’s intensity has actually decreased slightly, there is no corresponding decrease in the earth’s temperature. Global warming is not due to natural causes. Greenhouse gas emissions are largely due to human activity. Skeptics argue that these greenhouse gases are the result of natural causes. While greenhouse gases have always been naturally present in the earth’s atmosphere, it is an indisputable reality that “Since the mid-nineteenth century the relatively slow natural fluctuations of atmospheric CO2 levels have been overwhelmed by the exponential growth of fossil fuel consumption, releasing carbon previously sequestered for tens to hundreds of millions years in coals, oils and gases and by the concurrent extensive conversion of grasslands and forests to farmlands and built-up areas” (Smil, 1990, 2). This contention is validated by scientific measurements based on the analysis of air bubbles trapped in the polar ice. These results show that CO2 concentrations levels, which were between 275 and 280 parts per million during the eighteenth century, accelerated to about 300 ppm by the beginning of the twentieth century and went on to become more than 310 ppm by the early 1950’s. This increase coincides with the invention of the internal combustion engine. Extensive scientific studies are in agreement that “the atmospheric concentration of greenhouse gases is rising as the result of various human activities, of which the burning of fossil fuels is the most important.” (Bongaarts, 1992, 300). Since the beginning of the industrial revolution, the concentration of CO2 has risen by 25%. Other greenhouse gases, such as methane, nitric oxide and chlorofluorocarbons also show similar increases: “Methane concentrations roughly doubled during the industrial era and chlorofluorocarbons have been increasing much more rapidly” (Smil, 1990, 6). The chain of causation for Global Warming may be stated as follows: Human production and consumption activities – emission of greenhouse gases – atmospheric concentration of greenhouse gases – global warming. (Bongaarts, 1992, 301). The IPCC report gives a 70% increase in greenhouse gas emissions, due to human activity, from 1970 – 2004. The colossal increase in the concentration of greenhouse gases in the atmosphere since 1750 (pre-industrial times), demonstrates that Global Warming is predominantly due to human activities. A detailed analysis of the sources of greenhouse gas emissions shows that 77% of Carbon-dioxide, the major greenhouse gas, is released into the atmosphere due to the use of fossil fuels for energy, transport and industry, 22 % by deforestation and the remaining by high energy production processes, such as chemicals, iron and steel and aluminum. The generation of electricity from the combustion of fossil fuels accounts for the largest emission of CO2. This is followed by the transportation sector, where emission results from the combustion of petroleum-based fuels. Demand for travel continues to increase due to population explosion, economic growth, urban spread, and controlled fuel prices. Residential and commercial activities significantly contribute greenhouse gas emissions: combustion of fossil fuels for heating and cooking emits CO2, methane and nitrous oxide; organic waste in landfills emits methane; wastewater treatment plants emit methane and nitrous oxide; chlorofluorocarbons are emitted from leaking air-conditioning and refrigeration units. In the agricultural sector, fertilizer application and some methods of tillage, such as flooding paddy fields, emit nitrous oxide. Methane is released through the flatulence of domesticated bovines, due to enteric fermentation. Stored manure emits methane and nitrous oxide. Rice cultivation and the burning of crop residues also emit these gases. Trees and plants act as ‘carbon sinks’ by absorbing CO2 from the atmosphere. Deforestation by man for timber and wood pulp, by shifting cultivation, conversion of forests into agricultural and pastoral land, mining, urban expansion, construction of roads, dams and other infrastructure leads to the loss of plant cover. This depletion of vegetation cover is a source of carbon emission. The breakup of global emissions by source (in 2004) is as follows: energy supply 26%, industry 14%, land use 17%, agriculture 14%, transportation 13%, commercial and residential building 8% and waste and wastewater 3%. (EPA, 2012). There can be no question that the increase in greenhouse gases, and subsequently, the increase in Global Warming, is anthropogenic. The consequences of Global Warming take on serious dimensions. Ecosystems are in danger all over the globe, particularly coastal and forest ecosystems. Increased coral bleaching and higher risks of wildfires are expected. As oceans absorb anthropogenic CO2, the water becomes acidified. This has adverse effects on corals. It is estimated that “Approximately 20 to 30% of plant and animal species assessed so far are likely to be at increased risk of extinction” due to rising temperatures (IPCC, 2007, 48). This extinction is expected to be caused by changes in the habitations, ranges and relationships of plants and animals, which may exceed their adaptation capabilities. Decreased crop production in lower latitudes will increase the risk of hunger. Changes in rainfall and temperature will result in the decrease of freshwater availability and draught. This will have a negative impact on agriculture, water supply, energy production and health. Serious health problems can be expected. The ranges of vector-borne diseases, such as malaria, dengue fever and yellow fever are likely to increase. Malnutrition, death, disease and injury due to extreme weather conditions, diarrhea and cardio-respiratory problems caused by higher concentrations of ozone in urban areas are other factors of concern. (IPCC, 2007, 48). Another adverse health effect of Global Warming is the risk posed by heat waves to elderly people suffering from cardiovascular and respiratory diseases. Again, asthmatics may face greater risks due to the increase in temperature and humidity-dependant allergens (Smil, 1990, 10). . A significant rise in sea-level is expected due to the thermal expansion of the oceans and the melting of glaciers and ice-sheets. This will cause the inundation of low-lying coastal lands and river-deltas. Island nations will be particularly affected. Furthermore, “Other potential impacts include flooding, coastal erosion, and salinization of coastal cropland and aquifers” and loss of forest cover (Meyersen, 1998, 446). The economic costs of loss of agricultural production and forest cover and rise in sea level could reach 5% per year of GDP. It is evident that unchecked Global Warming will have disastrous consequences. The threat posed by Global Warming calls for urgent remedial and preventive measures. A two-pronged approach to combating Global Warming, based on adaptation and mitigation, is recommended by the IPCC. Adaptation strategies cover various sectors and include: rainwater harvesting, water conservation, storage, desalination and reuse, and irrigation efficiency; crop rotation, erosion control, tree planting and soil protection; construction of seawalls and storm surge barriers, and reinforcement of natural barriers, such as marshlands, to prevent coastal flooding; implementation of climate-sensitive disease surveillance and control, safe drinking water, improved sanitation and emergency medical services; improved transport infrastructure, and energy-efficiency (IPCC, 2007, 57). Measures to control population growth are particularly important as, “More recently, since 1970, carbon dioxide emissions have risen at a rate approximately equivalent to population growth” (Meyerson, 1998, 449). Measures to mitigate Global Warming include: switching from fossil-based to clean, renewable sources of energy, such as wind, geothermal and solar energy; increased nuclear power; the use of fuel-efficient vehicles, mass public transport and cycles, and the development of bio-fuels; the use of efficient lighting, heating and cooling devices, well-insulated constructions and solar designs; industries which recycle energy and material, implement ‘carbon capture and storage,’ improved agriculture techniques, efficient management of livestock and manure, increased crop yields and use of organic fertilizer; afforestation and reforestation; composting of organic waste, waste water treatment and recycling and the optimization of methane oxidation in waste disposal. There is an urgent need for the governments of all nations to cooperate in the implementation of policies and instruments concerned with Global Warming. Integrating policies on Global Warming, establishing standards and levels of emission, levying taxes and charges on carbon emission, standardizing trade in carbon emission permits, offering financial incentives for carbon caps and raising public awareness of Global Warming through educational campaigns are all measures which will succeed only on an internationally coordinated plane (IPCC, 2007, 60). Global Warming has been scientifically validated. It is unequivocally real and the vast majority of published climate scientists believe that human activity is changing the climate. The danger of unchecked Global Warming is great and mandates that the issue is addressed on a war footing. All the potential methods for taking on Global Warming can succeed only if international climate change treaties are made stringent. The pressure exerted by vested interests, such as the oil-producing nations, must be resisted in the search for cleaner, renewable energy sources. Political will in collaboration with technological innovation is the best hope to combat Global Warming. Anthropogenic Global Warming must be combated in order to preserve our way of life and to let future generations enjoy the earth which is their rightful inheritance. References. Bongaarts, John. Population Growth and Global Warming. Population and Development Review. Vol. 18, No. 2 (June, 1992), pp. 299-319. Intergovernmental Panel on Climate Change. 2007. Climate Change 2007: Synthesis Report. Retrieved from http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf Meyerson, Frederick A. B. Population, Development and Global Warming: Averting the Tragedy of the Climate Commons. Population and Environment. Vo. 19, No. 5 (May, Smil, Vaclav. Planetary Warming: Realities and Responses. Population and Development Review. Vol. 16, No. 1 (March 1990), pp. 1-29. U.S. Environmental Protection Agency. 2009. Climate Change. Basic Information. Retrieved from http://www.epa.gov/climatechange/index.html Weart, Spencer. 2003. The Discovery of Global Warming. The Carbon dioxide Greenhouse Effect. American Institute of Physics. Retrieved from http://www.aip.org/history/climate/index.htm#contents Population Growth and Global Warming John Bongaarts Population and Development Review , Vol. 18, No. 2 (Jun., 1992), pp. 299-319 Published by: Population Council Article Stable URL: http://0-www.jstor.org.library.utulsa.edu/stable/1973681 Population, Development and Global Warming: Averting the Tragedy of the Climate Commons Frederick A. B. Meyerson Population and Environment , Vol. 19, No. 5 (May, 1998), pp. 443-463 Published by: Springer Article Stable URL: http://0-www.jstor.org.library.utulsa.edu/stable/27503599 Planetary Warming: Realities and Responses Vaclav Smil Population and Development Review , Vol. 16, No. 1 (Mar., 1990), pp. 1-29 Published by: Population Council Article Stable URL: http://0-www.jstor.org.library.utulsa.edu/stable/1972527 Read More