Climate change
A changing climate may sound as fiction to some but facts show that the climate is changing and drastically in this case. It is important to appreciate that the earth has been changing from over the ages as a natural phenomenon. The earth has come from the ice ages to the interglacial era and the glaciers are likely to become history. Much as change in climate is a natural happening, human activities are largely attributed especially over the last century to the present.
Indicators of climate change
Climate has definitely changed over the years and more drastically in the recent decades spanning from the beginning of the 20th century. There are many indicators of a changing climate leaving no doubt that this phenomenon is taking place at rather a faster rate than ever before. The Intergovernmental Panel on Climate Change (IPCC) gives assessment reports that show climate has changed and these are trusted facts. Among the major changes has been increase in the global temperatures both in the atmosphere and the ocean temperatures. This has in effect led to melting of glaciers eventually resulting in rise in sea levels. According to the IPCC Fourth Assessment Report Climate Change 2007, eleven of the last twelve years (1995-2006) rank among the twelve warmest years in the instrumental record of global surface temperature (since 1850) (IPCC, para 1). The report also indicates that although the increases in temperatures have been virtually all over the globe, the northern latitudes have experienced the highest increase. The average rate of rise in sea level as from 1961 has been 1.8mmyr although this increase since 1993 where it rose to a high of 3.1mmyr. attributed to this increase has been factors such as thermal expansion as well as melting snow. Snow has therefore been decreasing significantly with the Arctic sea ice shrinking by an annual average of 2.7 percent per decade as from 1978. Snow melting is highest during summers with an average of 7.4 percent per decade (see appendix 1).
Increase in precipitation over the last century is also a clear indicator of a changing climate. Eventually, drought stricken areas across the globe have also increased. Spanning from 1900 to 2005, the eastern parts of North and South America as well as northern Europe have experienced marked increases in precipitation. This is in contrast with the reducing precipitation experienced in southern Africa and Asia leading to droughts (IPCC, para 5). The cold days and nights have been replaced by hot days and nights with heat waves being more common in the last fifty years than any other time before. The North Atlantic has been having more tropical cyclones as from 1970 as compared to other areas. All these are clear facts that the climate is changing rapidly.
Causes of climate change
There exists a variation in causes of climate change prior to and post industrial era. The pre-industrial era change was mainly associated with natural processes whereas the post industrial era change is greatly contributed by human activities. Prior to 1780 (pre-industrial era), the drivers of climate change included variation in the earths orbit, variation in suns intensity and volcanic eruptions.
Energy from the sun is primarily responsible for the earths climate. The amount of solar energy received therefore determines the climate by a large extent. Eccentricity is the change in the shape of the earths orbit and together with changes in the earths tilt and precession is known to have an effect on the amount of solar energy that reaches the earths surface (U.S. EPA (a), para 3). The three orbital processes (eccentricity, tilt and precession) have been suggested to be crucial in causing ice ages as suggested by Mulitin Milankovitch. On the other hand, variations in the suns intensity can either lead to warming of the earths surface or cooling of the same. A reduction in the intensity of the sun from 1400-1700 is predicted to have caused North America as well as Europe to cool slightly, an era known as the Little Ice Age (U.S. EPA (a), para 4). Ocean currents are important in regulating heat distribution in the globe and they vary depending on whether the surface of the earth is warm or cool.
Volcanic eruptions are natural processes which led to climate change in the pre-industrial age. Volcanic eruptions lead to release of aerosols as well as carbon dioxide. Aerosols lead to temporary cooling by blocking the sun energy. Their effects are short lived since their existence in the atmosphere is also short. Carbon dioxide emissions from the eruptions however have a far reaching effect. Since carbon dioxide is a greenhouse gas, its release into the atmosphere exacerbates the greenhouse effect.
The post industrial era has experienced changes in climate with both the natural processes of the pre industrial era as well as human activities making a contribution. The marked increases in average global temperatures that characterize change in climate today have been due to increase in greenhouse gases. Increase in concentrations of carbon dioxide in the atmosphere has been the main factor in addition to release of other greenhouse gases. The current change in climate has been due to global warming which forms the next section of this paper.
Global warming
Global warming is a modern world challenge which has resulted to climate change among other adverse effects. It is an environmental phenomenon that has altered the atmospheric concentration of gases leaving the world at risk of excessive warming and eventual change in life. Human beings are to blame for this phenomenon as they have endeavored in industrialization among other activities that have disturbed the equilibrium. Through deforestation and increased production of green houses gases as a result of massive industrialization, man has put himself in a tight corner with not only his resources being at risk of being depleted but also his own life. The developed industrialized world has been a major contributor to this phenomenon that transcends national boundaries hence a global issue. Economic and environmental consequences of global warming are felt all over regardless of whether a country is a producer of greenhouse gases or not. It is for this reason that the globe needs to unanimously adopt measures to reduce this phenomenon.
What is global warming
Global warming implies an increase in world temperatures (Stanford Solar Center, para 1). Naturally, the globe warms through the greenhouse effect. The atmosphere is naturally made of such gases as carbon dioxide, nitrous oxide as well as methane which keep the atmosphere warm. The sun is responsible for bringing in energy into the earths climate which gets absorbed by the land and water bodies. The greenhouse effect results when the earth radiates infrared energy outwards whose portion gets absorbed by the greenhouse gases. The energy is then re-emitted by the atmosphere and in the process the earth gets warmed by some of the energy. At the same time, some of the energy is released into space. If it happens that the amount of the greenhouse gases increases, then the greenhouse effect is amplified. This is because the extra concentration of the greenhouse gases means that more energy is trapped in the atmosphere leading to increase in temperatures beyond the normal a condition known as global warming (Koshland, p 1 ). (See appendix 2).
Naturally, carbon dioxide in the atmosphere is balanced through the carbon cycle. A short-term carbon cycle involves the process of respiration where carbon dioxide is mainly released and then photosynthesis where carbon is mainly used up. This happens between plants and animals. Under the short cycle, gaseous exchange also takes place between water bodies and the atmosphere. A long-term carbon cycle happens over millions of years whereby atmospheric carbon forms carbonic acids upon absorption in water. The weak acids are able to cause rock dissolution over a long period of time and once carried into the oceans, coral reefs as well as shells form by sedimentation. As continental drifts take place carbon in form of the shells moves deeper into the earth crust. Since this natural carbon regulation process is very slow, introducing high concentrations of carbon dioxide into the atmosphere implies that the natural way of balancing carbon dioxide in the atmosphere cannot handle the high concentrations of carbon dioxide emitted into the atmosphere (Koshland, p 4). This leads to increase in the greenhouse gas in the atmosphere and the subsequent global warming effect.
Causes of global warming
As earlier noted, increase in concentrations of greenhouse gases such that they trap heat in the atmosphere leads to global warming. Carbon dioxide as a greenhouse gas is emitted though natural processes in addition to the possible human activities. Human activities are however the main contributors to increase in levels of greenhouse gases in the atmosphere. Human activities that lead to the release of carbon dioxide in the atmosphere include combustion of fossil fuels such as coal and oil, burning of solid wastes as well as products from trees. Industrial processes such as chemical reactions involved in manufacturing cement also release carbon dioxide into the atmosphere (U.S. EPA (b), para 4). The natural processes leading to release of carbon dioxide is respiration and this is taken up by plants through the process of photosynthesis. It is important to note that carbon dioxide is the most important greenhouse gas that leads to global warming despite it lower heat-trapping ability since it is released in large quantities compared to other gases. Carbon dioxide is estimated to lead to an increase in warming with roughly 1.4 watts per square meter (Koshland, p 1).
Another gas which is a major contributor to global warming is methane. Sources of methane gas include human activities such as coal production and transport, landfills, production of natural gas as well as production and transport of oil. Farming practices such as livestock farming also adds up to release of methane in the atmosphere. Grazing animals particularly cows are known to release methane during their digestive process (National Geographic, para 3). Their diet that is primarily composed of grass in addition to the fact that they have multiple stomachs amplifies the amount of methane released. Rice farming is also a potential contributor to increased methane in the atmosphere. When solid wastes decay, methane gas is also released into the atmosphere. Methane has a high heat-trapping potential with a single methane molecule producing more than 20 times the warming of a molecule of carbon dioxide (National Geographic, para 4).
Human activities that lead to release of nitric oxide also add up to the concentration of greenhouse gases. Such activities include agricultural processes involving use of synthetic nitrogen based fertilizers. Industrial processes and refrigeration also add up to release of nitric oxide just as burning of fossil fuels does. Compared to heat-trapping capability of carbon dioxide, nitrous oxide is 300 times more powerful (National Geographic, para 4). There are also a variety of fluorinated gases with potential greenhouse effect. Fluorinated gases are classified as high global warming potential gases due to their high potential to deplete the ozone layer (U.S. EPA (b), para 4). They are produced through industrial process and such gases include hydrofluorocarbons and chlorofluorocarbons.
Industrialized economies such as the United States are well known to be among the leaders in releasing greenhouse gases. This is through various sectors of the economy with some sectors leading compared to others. In 1997 for instance, industrial processes released up to 610 million metric tons of carbon dioxide. The second sector was transportation sector which contributed up to 470 million metric tones whereas residential sector had 300 million metric tons. The agricultural sector emitted 120 million metric tons whereas the commercial sector released 280 million tons (Koshland, p 2). It is no doubt that the developed world as well as large developing economies are the leaders in emission of greenhouses gases.
As of 2006, the top twenty leading emitters of carbon dioxide were China, United States, Russia, India, Japan, Germany, Canada, United Kingdom, South Korea, Iran, Italy, South Africa, Mexico, Saudi Arabia, France, Australia, Brazil, Spain, Ukraine and Poland in that order. This is based on a report by Energy Information Agency (Department of Energy) (Union of Concerned Scientists, p 1). Notable is that the developed nations among these twenty countries lead in terms of per capita emission. While China is the leading emitter For instance, it has a 4.58 per capita emission as compared to Canada which is position seven but with a per capita emission of 18.81 or Australia which is position 16 but with a per capita emission of 20.58.
The importance of trees in regulating carbon in the atmosphere cannot be underestimated. The process of photosynthesis is particularly of importance in absorbing carbon dioxide from the atmosphere thus checking its concentration. Any process or activity that hinders the process of photosynthesis is therefore going to lead to an increase in the concentration of carbon in the atmosphere and global warming subsequently occurs. On this note, human activities such as deforestation which has been very prevalent both in the developed and developing world has distorted the carbon cycle leaving the atmosphere with excessive carbon dioxide which traps more heat. Trees create a carbon sink thus reducing the concentration of carbon dioxide in the atmosphere but with deforestation, this role is impaired. In fact deforestation is adding up the amount of the main greenhouse gas into the atmosphere in that the combustion and decaying of the cut trees releases carbon dioxide. This becomes almost a double impact of the process of deforestation to global warming (Dunaway, p 41).
It is also possible to have an increase in the levels of greenhouse gases more so carbon dioxide due to natural (also largely influenced by human activities) processes. Large water bodies such as oceans are involved in carbon cycle thereby reaching a balance. This implies that altering the oceans in terms of its biology or circulation distorts carbon balance. Through the interaction between ocean currents and atmospheric winds, excess carbon dioxide may be introduced into the atmosphere leading to global warming. On the same note, natural processes like volcanic eruptions also amplify global warming.
Human activities leading to production of greenhouse gases remain central to global warming and solar variability has only a slight contribution. It has been appreciated that solar irradiance has changed but by very minor proportions thereby leaving greenhouse gases as the main contributor of global warming. As per Goddard Institute for Space Studies, the solar increases do not have the ability to cause large global temperature increase. In any case, the suns brightness has been going down since 1996 when the last solar minimum was experienced yet 2009 was the second warmest year on record (Stanford Solar Center, para 6).
Effects of global warming
Global warming has not come without a variety of impacts on the climate, the environment and every other living organism without excluding man. There are early signs that indicate global warming and its effects. Global temperatures tend to become warmer in general whereas various areas in the globe start experiencing heat waves in addition to a typical warm weather. Ocean warming as well as rising sea level also indicates global warming. Other early global warming signs include glacier melting and warming in the Arctic and the Antarctic poles (Climatehotmap, para 1). With continued global warming, such signs as occurrence of infectious diseases, having spring season arrive early bleaching of the coral reefs and unusual droughts and flooding are a common phenomenon. These are clear signs of a changing climate.
Climate change and its consequences as a result of global warming
Although climate change is a phenomenon occurs naturally, the world has moved from the Ice Age to a point where glaciers have melted and sea levels increased significantly. The El Nino phenomenon has been experienced over years mainly around the equator mainly due to warmer eastern Pacific. The effects of such phenomena are variations in world climate. There are frequent episodes of drought and excessive rainfall all of which bring havoc to life and the economy (Koshland, p 4). Changes such as melting of glaciers and lack of ice age was seen as good news to those living in the Northern climes but this has come to be a devastating event. Climates were being viewed as changing to the more equable climates but this has drastically affected the world as global warming heightened in the mid 20th century (Discovery of Global Warming, para 2). Increase in global warming has therefore led to several aspects of climate change.
As mentioned earlier, global warming is first characterized by increasing temperatures especially during winter and at night. Over the last few decades, global temperatures have been rising drastically as compared to ancient days and the temperatures are predicted to even go higher. The global warming phenomenon has been acknowledged so far with the current increase in global temperatures being projected to be the highest in the past 400 years or so. Over the 20th century, global temperatures rose from roughly 0.3C to 0.6C. Stanford Solar Center (para 1) says that this is the largest increase in surface temperature in the last 1,000 years and scientists are predicting an even greater increase over this century. It is in fact estimated that the average increase in global temperatures over the twenty first century will be from 1.4 C to 5.8 C. It is estimated that as from 1990 greenhouse emissions have increased significantly by about 20 percent with annual increases being roughly six billion metric tons of carbon dioxide equivalent (National Geographic, para 5). The warmest years in the 20th century were noted to be experienced beginning from 1980.
With rise in global temperatures, sea levels are rising gradually. Due to rising temperatures, glaciers have continued to melt dramatically leading to the rise in sea levels. The Pitzal Glacier in Australia is in record of melting unusually especially during summer season. The glacier has been experiencing extensive melting extending up to a period of four months. This has forced some of the local community members to find ways of preventing this melting by basically putting up efforts of making the glacier remain cold during summer. Zwingle (para 2) says that owners of the Pitzal Glacier ski resort decided to cover the glacier with huge white blankets and spread them across 15 acres of glacier to keep it cold through the summer. Even with such measures, melting seemed to continue at a relatively high rate. The extent of sea ice in the Northern hemisphere has dropped by a record 10 to 15 percent as from 1950. A forty percent decline in sea-ice thickness in the Arctic summer is significantly high. With subsequent rise in sea level, the implication is that populations along the coastlines will be displaced and people will experience massive losses as they abandon their ancestral homes. Globally, the sea level ranges from 3.9 to 10 inches as a result of oceanic thermal expansion and glacier melting. The high rate of increase in global seal levels has gone hand in hand with increase in heat content of the ocean (Union of Concerned Scientists, p 2).
Global warming has also led to significant changes in weather patterns from earlier ones. There has been an increase in unusual droughts and floods over the recent decades which have been in line with increasing global temperatures. It is no longer a prediction that these extreme weather conditions are bound to happen with global warming. In 1997 for instance, Florida experienced unusual historic heavy rainfalls linked to El Nino. The following year was followed by an unusual historic drought attributed to cooling of the eastern Pacific (Koshland, p 5). Periods of El Nino have been more frequent and intense, occurring within the span of 2-6 years and usually cause great havoc. There has also been unusual precipitation patterns with high precipitation being experienced in mid to high latitudes whereas the tropics have had decreased precipitation. This has led to either extensive droughts or rains. Severe El Nino and precipitation events are almost a sure phenomenon now and in the future with increased global warming. In 2005, the Katrina hurricane was experienced in the U.S. and ranked as among the deadliest hurricanes. The same year was in record of having 27 storms in the Atlantic with the number of major storms increasing compared to other years. With increasing global temperatures, there has been an increase in annual precipitation with a 5-10 percent increase being recorded as from the beginning of twentieth century. This has consequently led to heavy downpours with the Intergovernmental Panel on Climate Change (IPCC) indicating that heavy downpours have been on increase over the past 50 years (NRDC, p 1).
Increase in global temperatures is a bad spell to species inhabiting the Artic regions and almost every other region of the globe. These organisms are forced to either migrate to favorable habitats or become extinct. It is forecasted that up to 25 percent of mammals and 12 percent of birds will be extinct in a few decades to come if the global warming phenomenon escalates (Europa, p 3). This implies that species migration is a common phenomenon resulting from global warming and with this follows conflict between man and wildlife due to stress on ecosystems (Discovery of Global Warming, para 41). Wildfires for instance have been on rise due to persistent hot and dry weather. In 2006 alone, there were about 100,000 wildfires that affected close to 10 million acres of land (NRDC, p 2). Wildfires destroy the natural habitats for animals, kills wildlife, cause some to migrate and eventually add up to the amounts of carbon dioxide in the atmosphere thus enhancing global warming.
Human health has been affected adversely by global warming. There has been an increase in occurrence as well as severity of heat waves leading to deaths. In 2003, temperatures in France reached a high of 104F killing almost 15,000 people (NRDC, p1). North America also experienced a severe heat wave in 2006 killing more than 140 people. In addition to heat waves, there has also been a rise in smog pollution. Air pollution leads to more allergic conditions such as asthma. Increase in carbon dioxide levels enhances growth of ragweed and subsequent pollen than exacerbates asthma. Rising global temperatures are speculated to cause a rise in production of ground-level ozone adversely affecting asthmatics. Extreme weather changes resulting from global warming is leading to outbreaks of diseases including infectious, waterborne and food borne diseases. Among the most serious disease outbreaks include highland malaria and diarrhea among other conditions (NRDC, p 4).
The economic impacts of global warming are definitely huge. There has been an increase in malnourished populations due to droughts and floods resulting from global warming. This lays a huge financial burden to individual states and the whole world. Huge amounts of money have to be spent in catering for displaced persons whenever storms and floods occur. It is estimated that close to 50 million people across the globe will be environmental refugees by the close of 2010 (NRDC, p 4).
Arguments for and against human caused global warming
From the above extensive discussion, it is clear that global warming is already affecting man and that it is the price to pay for increased industrialized economies. There are a few reasons to continue with the activities leading to emission of greenhouse gases but the reasons against the same are more founded.
The world has advanced to this far due to advances in technology and more so due to industrialization. The transport industry for instance has made life easier for man and were it not for use of fossil fuels and natural gas in these sectors, these advances probably would not have been reached. Restricting the use of fossil fuels as a measure to reduce greenhouse gases would therefore hurt most world economies that rely almost entirely on this source of energy. Human beings can therefore choose to suffer global warming and continue enjoying a flourishing economy. This argument however does not hold much water considering the havoc resulting from global warming. Deadly storms, hurricanes and floods are proving very costly to economies that get hit and the world at large. It would even be cheaper to take control measures such as developing economies through green and renewable energy than to suffer costs in handling global warming effects.
It has been argued that the production of greenhouses gases can continue so long as people adapt to the changes thereof (Europa, p4). The adaptation would entail being aware of forthcoming disasters due to climate change and then going ahead to prevent the disasters or reducing their potential damage. For instance in the event that droughts may persist, governments may prepare by developing food crops that are drought tolerant. To counter rising sea levels, governments can put up defenses that would control the rising sea level hence preventing displacement of people. The idea sounds wise but it is very costly to implement. This would hurt some countries such as the poor developing countries which are not in a position to take such measures. It is also unjust to have the developing countries bear the consequences much when they are the least emitters of greenhouse gases (Koshland, p 7).
Human caused global warming is a self destruct move which if not checked as soon as possible will cause extinction of virtually all species including human. The rate of global warming and the severity of its effects will probably exceed mans knowledge and ability to counter it or even to live with it thus proving more of a destructive than a constructive process. Unsustainable economies, human-human and human-animal conflicts and deaths resulting from disasters such as floods, drought and diseases will be too much for mankind to bear if global warming moves at the rate that human beings are driving it.
Conclusion
Change in climate has for real taken a record rate in the recent past. Higher global temperatures than normal have characterized this phenomenon leading to further changes in climate. Human activities have been driving this change at a high rate more so in regard to global warming. Were it not for increase in greenhouse emissions especially carbon dioxide, the current state of global warming and its consequences would not be a global threat. No matter how much human processes leading to global warming may be profitable, options must be considered to avoid self destruction and to ensure a sustainable world.
Categories:
0 comments:
Post a Comment