1.0 INTRODUCTION The consumption of fossil fuels has contributed much to the degradation of our environment. Global warming, climate change, extinction of wildlife species and habitat, depletion of Ozone layer, increases in air and water pollution have continued to create problems and on these our environment is suffering. The alarm calls for some action and need to be addressed. The issue of the global warming requires cautious handling. Though the earth’s average surface temperature increases due to such greenhouse gases like Carbon dioxide and methane, these gases are required for the presence of life on earth.
The global warming is really happening due to over-emittance of these gases. The enrichment of the gases in the atmosphere often results through air and water pollution. Wars have also greatly contributed to global warming. This should not surprise us. All the bombs going off, all the rockets, all the planes and helicopters. All the fuels of various kinds that are being used. They pollute the air and water of the very fragile and interconnected plane.
2.00 OVERVIEW OF GLOBAL WARMING(CONSEQUENCES) The effects of global warming cannot be over-emphasised. Certain facts have been made available. According to IPCC 2007 report ,sea levels are likely to rise by 0.18m by the end of this century due to global warming; since 1880, the average temperature of the earth has risen by 0.7degrees celcius.; the last two decades of the 20th century have been the hottest in 400years;the Arctic has been identified as one of worst places being effected by global warming as the Arctic ice is rapidly melting up, tending to ice summer. According to the multinational Arctic climate impact assessment report,2004: the Arctic ice region is likely to have ice summer by 2040,the polar ice not being an exception; the Montana Glacier National Park has 25 glaciers instead of the 150 that have been there in 1910; coral reefs are suffering the worst bleaching with a highest dying number since 1980; there are easily grave forest fires, heat waves, drought, hurricanes and severe tropical storms globally ;there has been tremendous increase in evaporation of water vapour, carbon dioxide, methane, nitrous oxide and other greenhouse gases due to polluting substances emitted as a result of industrialization, pollution, deforestation; humans are emitting more carbon dioxide in the atmosphere, faster than the absorbing plants and the oceans; sea levels have risen about 0.18m in the past 100years,threatening the lives of people particularly in the coastal areas; around 100million people live with 0.91m sea level, being vulnerable; melting of glaciers cause sea levels to rise; more than 1million species are becoming extinct due to the disappearance of habitants and ecosystems; the rate at which carbon dioxide is being dumped in the environment is 37 billion metric tons per year, with much of this from human activities; the carbon dioxide levels in the 20th century is the highest 650,000years; burning of fossil fuels like coal, oil and gas has been responsible for many respiratory diseases and large scale deaths; each year of the 21st century so far ranked among the 14 hottest years since 1880; the colder areas of the world are becoming hot more and more vulnerable to diseases; heat related illness and deaths are expected to rise globally; global warming leads to massive food and water shortages and these are life threatening both to humans, plants and wildlife. The depletion of the Ozone layer because of global warming was alarmed in the mid 1970s. An atmospheric chemist (Frank R and Mario M, 1987) discovered that chlorofluro carbons while inert in the atmosphere breakdown in the stratosphere in the presence of Ultra-Violent radiation , freezing chlorine atoms that combine with oxygen obtained from Ozone molecules. As a result of the incidence, there is a thinning down of the Ozone layer that protects the earths surface from lethal amounts of Ultra-Violent radiation. Knight, J et al 2009, had hinted that the amount of dissolved Oxygen in the Oceans may decline because of global warming, raising adverse consequences to marine life. The Oceans serve as a sink for carbon dioxide, taking up much that would otherwise remain in the atmosphere, but increase levels of the carbon dioxide have led to Ocean Acidification. The acidification makes life difficult for organisms that build shell out of calcium carbonate. The organisms include corals, shellfish and pteropods that form the foundation of marine food webs. As the temperature of the Ocean rises, the ability to absorb excess carbon dioxide wanes. The effects of global warming on Oceans are continually being cited by researchers. The effects in rising sea levels due to thermal expansion and melting of glaciers and ice sheets, and warming of the Ocean surface , leading to increased temperature stratification was again noted.(White, 1995). The greenhouse effect, a process by which absorption and emission of infrared radiation by gases in the atmosphere warms the earth’s surface has been continued to be of interest to researchers .(Meehi et al,2005) From the United Nation fifth report (AR5,2014) of the Intergovernmental Panel on Climate Change: temperature increased 0.65-1.08 degrees celcius from 1880 to 2012; carbon dioxide dumping into the air is rising and was about 1300tons/second in 2013;carbon dioxide level was noted highest in 650,000years, up by 40 percent due to industrialization. The earth is seen to be getting hotter day by day; roughly 10 times faster than any time since the past 800,000years.National Aeronautics and Space Administration (NASA) had taken a look at the global temperatures back 800,000years and saw that the global mean temperature has never risen this fast .As the earth moved out of the ice age, the global temperature according to the report rose a total of 4-7degrees celcius over a period of 5,000years. They predicted rate of warming for the next century to be at least 20times faster. On carbon dioxide levels, the report had it that the atmospheric carbon dioxide has never been as high as today-0ver 400parts per million, never at any time during the past 400,000years.In those years, it hovered just between 200-280 parts per million. On sea level, the report had it that the global sea level continues to rise at 0.32cm annually, due to melting glaciers and ice sheets, increase rate of carbon emissions and the thermal expansion of the ocean waters as they warm. According to National Oceanic and Atmospheric Administration (NOAA) Releases 2016 Arctic Report Card: Emissions of pollutants warm the climate. A specific culprit is Ozone, which results from the emissions from cars, power plants, industrial boilers, refineries, and chemical plants reacting with sunlight in the atmospheric. If Ozone depletion continues to increase, this will cause widespread health problems: shortness of breath; pain when taken a deep breath; coughing; sore or scratchy throat; inflamed and damaged airways; aggravation of diagnosed lung diseases: asthma, emphysema, and chronic bronchitis. The same report has it that marine species are moving to the poles to stay cool as the average ocean temperature rises and that the large shifts can cause ecological disruptions as predators are separated from their typical prey. 3.00 THE GREENHOUSE GASES 3.10 METHANE (CH4)The atmospheric content of methane has been increasing annually at rate of 0.8 to 1.0 percent. Increases in methane track well with population growth rates. (Glantz and Krenz, 1992) Human activities such as wet rice cultivation, domestic ruminant breeding, landfills, biomass burning, coal mining and natural gas venting including leaks from natural gas pipelines have contributed to the atmospheric concentration of methane. (IPCC, 1990)There are natural sources of methane of methane emissions such as termites, wetlands, both of which can be influenced by human activities. Methane is produced by the activity of bacteria breaking down organic matter in relatively oxygen free condition. Warmer condition are likely to increase the ecosystems and, in the process, methane emission. (DACEY et al, 1994)3.20 OZONE (03)High level Ozone layer is a major absorber of short-wave Ultra-violent radiation and is primarily important in maintaining the temperature structure of the stratosphere. Ozone at lower level is also an important absorber of long-wave infrared radiation. The addition of Ozone at height below 30km causes net atmospheric warming while above this height there is cooling of the stratosphere zone that accounts for about 90 percent of the atmosphere’s concentration. About 10 percent of atmospheric zone occurs lower breaks down the in the troposphere. Troposphere Ozone down under Ultra-violent radiation into oxygen atoms which reacts with water vapour to produce hydroxyl radical, which helps to regulate the levels of methane. (White, 1995)3.30 CHLORO FLUOROCARBON (CFCS)Chlorofluoro carbon (CFCs) was discovered in 1920 and are used as cleansing solvents, blowing agent(s, refrigerants, fire retardants and as propellants in aerosol sprays. Glantz and Krenz, 1992) They are chemically inert and have a long residence time in the atmosphere, estimated at 60 to 200years. In the stratosphere, they are subjected to photo dissociation after which the free chlorine combines with Ozone to form other compounds. This process make very efficient Ozone destroyer. In addition to the destructive tendency, CFCs are also efficient in trapping long wave radiation, thereby enhancing the greenhouse effect. (Glantz and Krenz, 1992)3.40 NITROUS OXIDE (N2O)Nitrous oxide is generated mainly from soils, especially by the use of fertilizers and agriculture. About 90 percent of the global emissions come from soils. The huge rise in the production of synthetic fertilizers in recent decades has increased the release of nitrous oxide to about 100 tonnes grammes of nitrogen annually. (Levenberger M and Siegenthaler U, 1992) Other identified sources of nitrous oxide occur in the production of nylon and nitric acid. Nitrous oxide is fairly stable in the atmosphere with a lifetime of about 150 years. (White, 1995) The potential as a greenhouse gas is about 230times that of carbon dioxide molecule to molecule. Even where the concentration is far lower, it is potentially a significant contributor to global warming, accounting for about 5 percent of the cumulative radioactive force to date. Nitrous oxide is broken down in the stratosphere by Ultraviolent radiation in a photochemical reactions which contribute to the depletion of Ozone. (Glantz M H and Krenz J H, 1992) Conversion of rain forest to pasture has also been seen as an important source of nitrous oxide. Research has shown that there is an increase in the release of nitrous oxide from soils cleared for pastures in the Amazon compared with the original rain forest soils. The conversion of forest to pasture contributed up to 25 percent increase in nitrous oxide. The investigation however revealed that rate of increase of the nitrous oxide from such land only lasts for a few years, after which the amount falls off to half or one third of those of the original forest soils (Keller M et al., 1993).4.00 HEALTH ALARM OF GLOBAL WARMINGThe global warming increases the frequency of Hurricane and other natural disasters such as coastal erosion, flooding, landslides, loss of wetlands, salt water intrusion by affecting weather patterns. As global temperatures rise, the oceans warm up and expand, ice caps and glaciers melt, and more precipitation falls as rain instead of snow. This causes sea levels to rise. Coastal communities are particularly vulnerable. (John V A, 2016 ; Olugbenga A O, 2016). In consequent to these, there are increases in the appearance and development of disease vectors. Hurricanes can cause the spread of water-borne disease such as cholera and salmonellosis. Vector-borne diseases of concern include leishmania, dengue fever ,Asthma, and malaria. Malaria infects approximately 500,000 people and cause more than two million deaths per year.( Amadi A N, 2014).4.0 CONTROL OF GLOBAL WARMINGOn the strength of the knowledge of global warming and the havoc associated with it particularly on humans and the environment, there is the urgent need for a clarion call for a control of the cankerworm. Scientists have used sophisticated computer models called general circulation models to incorporate observations of many factors that have an influence on the vagaries of weather in order to study past, present and future weather patterns. These models projected an increase in global average temperatures that will continue for decades as a result of the greenhouse gas emissions. In a bid to tackle the problem of global warming, nations around the world in the late 1980s and early 1990s rallied round to develop policies of control to the emission of the greenhouse gases. Toward this end also the World Meteorological Organization and the United Nations Environment Programme formed the Intergovernmental Panel on Climate Change (IPCC) in 1988 to monitor, advice, and proffer possible checks to the global warming. Further development on this is contained in the United Nation’s fifth 2014 report, aimed at creating the awareness of the global warming, advising on control and mitigation strategies through communiqu©. Presently in Nigeria different bodies like : Nigerian Erosion and Watershed Management (NEWMAP), Nigerian Standards and Regulation Enforcement Agency (NESREA), Nigerian Meteorological Agency (NIMET), Nigerian Hydrological Agency (NHSA), National Emergency Agency (NEMA), Nigerian Airspace Research and Development Agency (NASRDA),Nigerian Geological Survey Agency (NGSA), River Basin Development Authorities, Environmental Consultants, Institutions of higher Learning and Ministries have been working in synergy to tackle relentlessly the issue of global warming. Late last year the World Bank in collaboration with the Food and Agricultural Organisation and National Erosion and Watershed Management, in a well thought out idea, set up a State of the Act automated Meteorological Station in the Institute of Erosion Studies, Federal University of Technology, Owerri, Nigeria to empower the University in particular and Nigeria in general to monitor, study the weather trend on a continuous basis to possibly produce weather digest that could help inform, advise on strategies and practices that could ameliorate global warming.5.00 MITIGATION OF GLOBAL WARMINGMitigation of global warming could be accomplished through reductions in the rate of anthropogenic greenhouse gas release. Global warming requires global solution. The world’s primary international agreement in reducing green house gas emission, the Kyoto protocol, covers more than 160 countries and over 55 percent of global greenhouse gas emissions have been achieved . There are considerable efforts to improve energy efficiency and moves towards the use of alternative fuels such as nuclear energy are advocated. In January 2005, the European Union introduced its own European Union Emission Trading Scheme, through which companies in conjunction with Government agree to cap their emissions through a carbon cap and carbon tax agreement. Australia unilaterally announced its carbon pollution reduction scheme in 2008 . United States of America has also announced plans to introduce an economic wide cap and trade scheme to check and mitigate on global warming and climate change. (World Bank, 2010).8.00 CONCLUSIONGlobal warming has been proved beyond reasonable doubt to be wrecking the earth and as such we should not wait tirelessly for solution. It is a common enemy. Much have been unfolded in this report on the causes of global warming. Efforts has also been made in no small measure to unveil globally the havocs which the global warming has caused. It is in opinion of the authors that all hands are to be put on deck in researching and adopting policies cum attitudes that will not enhance global warming.