Global warming is the most significant environmental issue that the world currently faces. Essentially, global warming is an irreversible increase in temperatures of the earth’s surface owing to the greenhouse effect of gases in the atmospheres. Gases such as carbon dioxide, methane, and nitrogen oxides accumulate in the atmosphere and cause the greenhouse effect, which results in an increase in the temperatures of the earth’s surface.
The mechanism of the greenhouse effect is that greenhouse gases trap radiations from the earth’s surface and prevent them from escaping into the atmosphere. Over centuries, the average temperature of the earth’s surface has been increasing in response to the amount of greenhouse gases in the atmosphere. Climatologists have warned that increasing global temperatures due to global warming have serious effects on the existence of living things on the earth’s surface.
According to Hansen et al., scientific evidence shows that the temperatures of the earth’s surface have increased by approximately 0.2 degrees Celsius over the past three decades (14288). The trend of increasing temperatures is alarming because it threatens the existence of humanity and other living organisms. In this view, this essay examines the effects of global warming in a bid to explain why global warming is the most significant environmental issue that the world is facing.
Effects on the Sea
The rise in sea level is one of the notable effects of global warming on the sea. Global warming causes sea level to rise by melting of glaciers at the poles and causing thermal expansion of water in the sea. Given that the poles have many glaciers, they store a significant amount of water in the form of ice. However, the increasing global temperatures due to global warming cause glaciers to melt resulting in increased flow of water into the ocean.
In the aspect of thermal expansion, global warming increases the temperature of the water in the ocean and causes them to expand. Thompson states that thermal expansion accounts for half of the rise in ocean levels because water considerably expands when the temperature increases (163). Hence, melting of glaciers and thermal expansion of water contribute to the rising sea levels owing to global warming. The consequences of the rising sea levels are submersion of coastal areas and increasing frequency of floods. Hence, rising sea level is a serious environmental issue because the submersion of coastal areas and frequent floods cause death, destroy property, and displace humanity.
Global warming also threatens the existence of marine organisms. Temperature increase, acidification, and oxygen depletion are some of the major effects of global warming on the ocean. The increasing temperature of the ocean due to global warming makes a considerable proportion of marine organisms, which are sensitive to slight changes in temperature, to die. As carbon dioxide is a greenhouse gas that is mostly responsible for global warming, it dissolves in marine water and forms carbonic acid, which acidifies the water.
According to Cao, Wang, Zheng, and Zhang, evidence shows that the pH of the ocean has decreased by 0.1 units for the past three centuries and projection indicates that it will fall by 0.3 units by the end of the 21st century if the amount of greenhouse gases continues to increase (2). The increasing trend of acidification reveals that there is an exponential increase in the level of carbon emissions. The increasing temperature and acidification contribute to oxygen depletion in oceans. High temperatures usually reduce the solubility of oxygen in the water, and thus, making water become anoxia. Therefore, anoxia and acidification cause death and extinction of marine organisms resulting in their loss.
Effects on Weather
Global warming has marked effects on the weather because it has increased temperatures and reduced the amount of rainfall in most areas. In the past, the earth has experienced most cold and warm seasons, but currently, the cold seasons have reduced significantly and warm and hot seasons have increased considerably. The changing weather seasons and climatic conditions reflect the effects of global warming.
Cao, Wang, Zheng, and Zhang report that the temperature of the earth’s surface has increased by 0.3 degrees Celsius over the past three decades owing to the global warming. Such an increase is significant to change weather patterns and climatic conditions of given geographical area. Misra explains that global warming significantly changes rainfall patterns and reduces the amount of rainfall leading to the frequent occurrence of droughts in areas that have enough and reliable rainfall patterns (163).
For example, in Africa, arid areas have become deserts, semi-arid areas have turned into arid areas, and semi-arid areas have expanded into tropical and sub-tropical areas. In essence, global warming expands dessert and creates a barren land that does not support life. Hence, the increasing temperatures and reducing the amount of rainfall results in unpredictable rainfall and climatic conditions, which have adverse effects on people, organisms, and the environment.
Given that global warming influences weather and climatic conditions, it causes scarcity of water and food. The scarcity of water and food occurs because global warming causes drought, which consequently affects the production of food. In the past, water and food were in plenty because there was enough rainfall to provide water and promote the production of food. However, currently, global warming has reduced the amount of rainfall leading to declined availability of water and diminished food production.
Misra notes that the effects of global warming have reduced the amount of rainfall in Sub-Saharan Africa by 10% and the amount of drainage by 17% leading to scarcity of water and food (163). The 10% reduction of rainfall has a commensurate effect on the food production in Sub-Saharan Africa. Due to global warming, water has become a very scarce resource in both rural and urban areas (McCarthy, Best, and Betts 4). In rural areas, the springs and rivers have reduced their flow or dried up, and thus, affecting the availability of water for agricultural purposes. In urban areas, the available water does not meet the domestic and industrial requirements.
Misra argues that developing countries in Africa and Asia have experienced severe effects of global warming because they rely on rainfall in food production (157). In this view, water and food security have reduced significantly owing to the global warming. Thus, global warming is the most significant environmental issue because it causes scarcity of water and reduces food production.
Effects on Human Health
Global warming has significant effects on human health because it affects the production of food and the occurrence of diseases. Human health is dependent on the production and supply of sufficient food to the population. In the production of food, global warming has reduced food security and predisposed humans to famine and drought. Misra asserts that food insecurity is the greatest threat of global warming because it affects the greatest number of people across the world (159).
The insufficient production and supply of required food to humans has serious health effects. In this view, the insufficient production of food or food scarcity causes malnutrition among the global populations, particularly the poor. The countries that experience the greatest impact of food insecurity and malnutrition are the developing countries because they wholly rely on rainfall as a source of water in food production.
Global warming has increased the spread of infectious diseases such malaria and dengue fever. Mosquitoes usually spread these infections from one person to another and from one environment to another. Since the changing climatic conditions cause mosquitoes to migrate from their native environment to other favorable environments, they enhance the spread of malaria and dengue fever. In a similar manner, global warming promotes the spread of other infectious diseases when vectors change their environment by spreading to new favorable areas.
Global warming complicates the prevention, control, and treatment of infectious diseases because it promotes their spread and adaptation to new environments, which were earlier inhabitable (Thompson 167). Therefore, global warming promotes the spread of infectious diseases from one area to another through vectors that migrate in response to changes in weather patterns and climatic conditions.
Global warming increases the occurrence of natural disasters such as droughts, floods, hurricanes, and heat waves. Given that global warming reduces the amount of rainfall and increases temperature, it causes scarcity of water in extensive geographical areas leading to drought. In Sub-Saharan Africa, droughts have become frequent natural disasters that deplete vegetation, destroy crops, and causes death.
Rising sea levels have submerged coastal areas, destroyed property, and displaced humans in diverse countries that border oceans. Thompson notes that Netherlands and Bangladesh are some of the countries that have experienced frequent floods caused by global warming (164). The current incidences of floods witnessed across the world reflect the effects of global warming on the planet. Moreover, the frequent occurrences of hurricanes and heat waves in Asia emanate from global warming. According to McCarthy, Best, and Betts, global warming creates heat islands in urban cities resulting in the occurrence of extreme heat events (1).
These heat islands cause heat waves, which have marked effect on the lives of people in urban settings. Hence, global warming contributes to the occurrence of natural disasters, which destroy property and cause massive loss of lives.
Global warming is the most significant environmental issue that the world is struggling to overcome. Although global warming is merely an increase in the average temperatures of the earth’s surface, it has serious effects on environment and humans. Evidently, global warming causes sea levels to rise and submerge the coastal areas. Moreover, it causes acidification of marine water, depletion of oxygen, and the loss of marine life. Global warming also changes weather patterns and climatic conditions leading to scarcity of water and food. On human health, global warming increases food insecurity and malnutrition it reduces food production.
Since global warming changes climate and weather patterns, it changes habitats of mosquitoes, thus, contributing to the spread of infectious diseases such as malaria and dengue. The frequency of disasters such as floods, hurricanes, droughts, and heat waves has increased due to global warming. Overall, global warming is indeed the most significant environmental issue that has extensive and huge impacts on weather patterns, climatic changes, human health, food production, availability of water, and the occurrence of disasters.
Cao, Long, Shuangjing Wang, Meidi Zheng, and Han Zhang. “Sensitivity of ocean acidification and oxygen to the uncertainty in climate change.” Environmental Research Letters 9.1 (2014): 1-10. Print.
Hansen, James, Makiko Sato, Reto Ruedy, Ken Lo, David Lea, and Martin Median-Elizade. “Global temperature change.” Proceedings of the National Academy of Sciences, 103.39 (2006): 14288-14293. Print.
McCarthy, Mark, Martin Best, and Richard Betts. “Climate change in cities dues to global warming and urban effects.” Geophysical Research Letters 37.1 (2010): 1-5. Print.
Misra, Anil. “Climate change and challenges of water and food security.” International Journal of Sustainable Built Environment 3.1 (2014): 153-165. Print.
Thompson, Lonnie. “Climate change: The evidence and our options.” The Behavior Analyst 33.2 (2010): 153-170. Print.