Earth’s surface has recorded an unparalleled rise in temperature over the past century. The problem continues to intensify and may be catastrophic if it remains uncontrolled. According to Medhaug et al., “Every single year since 1977 has been warmer than the 20th-century average, with 16 of the 17 warmest years on record occurring between 2001and 2016” (43). The primary contribution to the increased temperature is emission from oil and coal. The world would not have witnessed 13 out of the 15 hottest years without the two causes (Medhaug et al. 45). Numerous forces (referred to as climate drivers or “forcings”) affect the earth’s temperature. They include heat-trapping gases, volcanic eruptions, and variations in solar intensity. Nonetheless, these forces have insignificant effects on the earth’s temperature because they rarely occur. Scientists have revealed that humans are significant contributors to global warming (Medhaug et al. 46). Indeed, global warming is a human-induced catastrophe. This article will discuss the role of humans in global warming.
Global Warming is a Myth
Skeptics of global warming argue that the phenomenon is a myth. They claim that the world has not witnessed a significant rise in temperature since 1998 (Hmielowski et al. 871). Jay Hmielowski has an interest in science and environmental communication. Currently, he works at Edward R. Murrow College of Communication as an Associate Professor. One wonders why 1998 and not any other year. It is imperative to note that they select the year because it coincided with El Nino. Individuals opposed to global warming argue that the reduction in temperature since 1998 signifies a fundamental turnaround (Dunlap 693).
Dr. Riley Dunlap is among the founders of environmental sociology. He has a doctorate degree in sociology from the University of Oregon. According to skeptics, 1998 marked the end of global warming. The skeptics fail to appreciate the fact that natural forces such as volcanic eruptions, La Nina, and El Nino cannot give conclusive results. Dunlap avers, “El Nino is responsible for warm ocean currents in eastern tropical Pacific, while La Nina generates cooler sea surface temperatures” (696). Such variations in the surface temperature of the sea may result in critical climatic changes across the world. Eliminating such factors clears the uncertainty regarding global warming.
Evidence of “Human Fingerprints”
The necessity to understand the causes of global warming, hence mitigate them has led to scientists coming up with models for analyzing climate patterns. Oceanographers and meteorologists have conducted numerous studies using state-of-the-art models of ocean and earth’s atmospheres. A comparison between the models and the real observed patterns has revealed the presence of “human fingerprints” that contribute to rising in temperature (Trenberth et al. 18). Moreover, scientists associate human activities with the present variations in climatic conditions. Records from the earth’s surface, atmosphere, and ocean point to human roles in the increased global temperature (Trenberth et al. 19). The current rise in temperature has emanated from people releasing a lot of carbon into the atmosphere. The increased use of oil, coal, and gas has led to the rise in the amount of carbon in the air. Moreover, deforestation and forest fires have augmented the level of carbon in the atmosphere, thus resulting in a rise in temperature. According to Trenberth et al., the level of carbon in the atmosphere has increased by at least 40% between 1800 and 2012 (21). Industrialization, agricultural production, and urban growth are among the human activities that dominated this era.
Analysis of various constituents of carbon (isotopes) confirms that the rise is due to human activities. Different forces that impact climate have distinct signatures (Trenberth and Fasullo 23). Kevin Trenberth is a renowned senior scientist at the National Center for Atmospheric Research. On the other hand, John Fasullo is a project scientist and research associate in the Department of Atmospheric and Oceanic Sciences (ATOC) at the University of Colorado. The distinct fingerprints are easy to detect by analyzing various elements of weather conditions. For instance, analysis of the regional and cyclic trends of climate variations may go a long way towards identifying the primary causes of temperature changes. The observed patterns in changes in atmospheric moisture, surface warming, melting of sea and land ice, and rise in sea level point to human-induced causes.
Carbon dioxide is the chief heat-trapping gas, which contributes to the increased temperature on the earth’s surface. Studies show that gas has played a critical role in the rise in the earth’s temperature over the last numerous decades. The level of carbon dioxide was below 280 parts per million (ppm) before industrialization (Trenberth and Fasullo 27). Industrialization led to the standard rising drastically. Today, the concentration of carbon dioxide stands at 400 ppm (Medhaug et al. 46). Iselin Medhaug is a senior scientist in climate physics at the Institute for Atmospheric and Climate Science in Zurich, Switzerland.
It is evident that human activities are contributing to the rise in the level of carbon dioxide. Atmospheric carbon dioxide bears information about its source. Scientists can easily ascertain the level of heat-trapping emissions that results from natural and human forces (Medhaug et al. 46). According to Tubiello et al., carbon from fossil fuel has distinct features (δ13C) (2657). Francesco Nicola Tubiello has a doctorate degree in Earth Systems Science from Walden University. He currently works at the Food and Agriculture Organization of the United Nations. Tubiello et al. hold, “The more negative the δ13C, the higher the proportion of carbon from fossil fuels” (2658). With time, the level of δ13C has gone down significantly. Despite the decline, the level of heat-trapping gas continues to rise, signifying the contribution of human activities.
Human and Natural “Forcings”
Individuals opposed to the issue of human contribution to global warming argue that natural “forcings” like a volcanic eruption, variations in solar intensity, and the carbon cycle are the leading causes of the problem. One should appreciate that major volcanic eruptions may have significant impacts on climate. For instance, eruptions witnessed in Mount Pinatubo Philippines and Krakatoa in Indonesia altered atmospheric temperature (Estrada et al. 1051). Dr. Francisco Estrada Porrua is a senior researcher at the Department of Environmental, Economic, Institute for Environmental Studies (IVM), Vrije University Amsterdam. They hold that global warming is an international phenomenon (Estrada et al. 1051). The impacts of global warming are felt across the globe. However, the effects of natural incidents like volcanic eruption are handled only within the affected region. Therefore, they cannot play a central role in global warming.
Human “forcings” include deforestation, soot, coal, oil, gas, and changes in agricultural activities. Industrialization and improvement in domestic income have led to many people owning cars. In Africa, the number of households with cars continues to rise. Indeed, traffic congestion has become the order of the day across the world. The high number of cars has led to increasing the level of heat-trapping emissions. Both natural and human “forcings” contribute to variations in climate. Some “forcings” lead to cooling and another warming of the atmosphere (Estrada et al. 1053). Nonetheless, when human- and natural-induced climate drivers are compared, the former appear to contribute significantly to global warming.
Scientists have devised computer programs that help to analyze the different climate drivers and their contribution to global warming. Researchers working under the Intergovernmental Panel on Climate Changes (IPCC) have an extensive record of observed changes in ocean temperature, the rise in sea level, air temperature, and ice retreat. The history helps to assess the validity of information gathered via computer programs. The IPCC has confirmed that anthropogenic drivers cut across the global climate system and contribute to the rise in atmospheric temperature (Tubiello et al. 2659). The panel found that human activities resulted in the high accumulation of carbon, leading to the rise in atmospheric temperature. One of the examples of human-caused global warming is the extreme heatwave that was experienced in Indian and Pakistan resulting in the death of over 4,000 people (Medhaug et al. 46). Medhaug et al. posit, “The trend towards more extreme weather events, combined with expanding urbanization, means that an increasing number of people in countries like Pakistan and India are at imminent risk” (47). Indeed, global warming poses a great risk to public health.
Global warming is a human-driven catastrophe. Increased use of oil and coal as the major sources of energy has led to the rise of the level of greenhouse gas in the atmosphere. Urbanization and agriculture have led to the reduction of forests, which help to balance the amount of carbon dioxide in the air. Scientists have found that a big percentage of carbon in the atmosphere is a result of human activities. Individuals opposed to global warming blame natural forces for the phenomenon. The fact that the earth’s temperature has continued to rise since the onset of industrialization is substantial proof that global warming is human-induced.
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Estrada, Francisco, et al. “Statistically Derived Contributions of Diverse Human Influences to Twentieth-century Temperature Changes.” Nature Geoscience, vol. 6, no. 1, 2013, pp. 1050-1055.
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