There has been an increasing concern among the scientific and geographical communities that the changes currently occurring in the climate are induced by humans. Scientists are also concerned about the ability of humans and other species to adapt to these changes. Indeed, there is an on-going debate about whether humans and other species should adapt to the change or mitigate it. With rapidly rising temperatures around the globe, the chances of sustainability are decreasing. Climate changes as a result of natural forces such as the earth’s rotation around the sun, and changes in the intensity of radiation of the sun’s rays. The changes occurring by these forces are however not great in magnitude. The recent changes that have been occurring, particularly the rise in temperatures around the world, are however, of great magnitude. These changes are thought to be because of human activities and the resulting greenhouse effect. This paper examines the concept of climate change and global warming, its causes and impact on human and other life.
Climate change and global warming have different meaning for different people. For some the terms merely refer to the change in climate and the increasing heat that is plaguing the earth while others perceive it as a serious problem that needs an immediate solution. The two terms are often used synonymously particularly in the media. However, the fact that the earth’s climate and climatic patterns are witnessing a change cannot be denied. Technically the two terms have different meanings. One refers to the increase in the average surface temperature of the earth while the other refers to the long-term changes in the climate. In this paper, we examine the meaning of the two terms, the causes of these phenomena, and their impact on human life.
Definition of Terms
We first define the terms Global Warming and Climate Change along with a few other important terms used in this paper.
Global Warming refers to a general increase in temperatures around the world. It has been scientifically proved that the climate in countries around the globe is warming (Hartmann et al., 2013). The increase in the surface temperature is popularly considered as a measure of global warming. However, Rhein & Rintoul (2013) state that, a large portion of climatic energy is channeled into warming the oceans and melting the ice. This has resulted in warming the climate over the continents. More than 90% of the climatic energy is expended on ocean warming. The remainder is expended in melting the ice over the Arctic sea, glaciers, and other ice sheets around the globe.
Climatic Change refers to change in the weather patterns in the long term. There are several causes for climatic change such as biotic processes, variations in the intensity of solar radiation, and human behavior. Global warming or change in temperature is considered a part of the climatic changes occurring around the world (Leiserowitz, 2014).
Another term that we use in this paper is climate. The common description of climate is changes in the weather conditions over a long period of time. However, a study by the Center for Inquiry shows that under certain conditions the climate can become unpredictable (Lindsay, 2006). Records show that over the last 400 millenniums, changes of over ten degrees in the earth’s temperature have occurred several times over a period of two or more decades (Folland et al. 2001 in Lindsay, 2006). Ice core temperatures have been comparatively stable (Cox 2005 in Lindsay, 2006). It is therefore difficult to define global climate. One may possibly define it as the average of the global weather over a specific time period taking into account the rate at which climatic changes occur.
It is also important to define mean global temperature. The mean global temperature is the average of temperatures over land and water. This average is weighted by the amount of data available.
Having defined the important terms, we now proceed to identify the causes of climate change and global warming. Based on the definitions, one may say that the two terms namely climate change and global warming are overlapping rather than synonymous.
Causes of Climate Change and Global Warming
The climate responds to external forces such as changes in solar radiation, volcanic eruptions, changes in the levels of greenhouse gasses, and variations in orbital cycles (Berger & Loutre 2002). The factors that influence climate are called climate forcings. These are mainly natural processes such as the sun’s radiation, variations in the reflectivity of the earth, continental drift, mountain building and the greenhouse effect (Epa.gov).
Lindsay (2006) identifies natural processes as the primary cause for climate change. Human activity has been identified as the second cause for the general rise in surface temperature. Lindsay refutes the claim that the persistent rise in the Sun’s heat is responsible for the rise in temperature on the grounds that there is no accurate data available to support the claim. In addition, Hudson (2004) in Lindsay (2006) shows that there is no increase in the sun’s heat. Lindsay similarly refutes other solar theories claiming that there is no evidence to support these theories (Ramaswamy et al. 2001 in Lindsay, 2006).
Lindsay also refutes the claim that the Earth itself is responsible for the changes in temperature and climate again claiming that there is no evidence for this (Stocker et al. 2001 in Lindsay, 2006). Other theories such as the urban heat island effect (Singer 2002 in Lindsay, 2006) and orbital dynamics (Morell 2004 in Lindsay, 2006) have also been refuted for lack of evidence. Lindsay attributes the rise in temperature and change in climate to the now well-known “greenhouse effect”.
The Greenhouse Effect
The green house effect is described as the process through which the surface of the earth is warmed by radiations from the atmosphere. The surface temperature rises to a level more than what it would be in absence of atmospheric radiation. (Ipcc.ch)
The combined effect of the sun’s ultra violet rays being absorbed into the atmosphere and the cooler and much longer rays radiated by the earth into the atmosphere is called the greenhouse effect. Only about 66% (2/3rd) of the energy radiated by the sun towards the earth is absorbed into the atmosphere and the earth’s surface. The earth too radiates energy. Due to the fact that the earth is much cooler than the sun, the rays emitted by the earth are much longer than those emitted by the sun are. A large part of this energy is absorbed into the atmosphere. This energy is then reflected back towards the earth. This phenomenon is called the greenhouse effect. The phenomenon is likened to a greenhouse where the glass walls trap the air and gasses, rising the temperature within the structure. Similarly, the earth’s atmosphere acts as a glass wall trapping gasses such as oxygen, nitrogen, and carbon dioxide within the atmosphere (IPCC, 2007). This greenhouse effect makes it possible for life to exist on the earth. In the natural greenhouse effect, the two gasses most plentiful are nitrogen and oxygen, both of which are not harmful to human life. However when the intensity of other gasses such as carbon dioxide and methane increase, the atmospheric temperature rises which is known as global warming (IPCC, 2007). It is this rise in the intensity of harmful gasses, which is considered the direct cause of global warming and climate change. The underlying causes of the increase in intensity of these gasses have been identified as human activity such as burning of fuel, deforestation, and other similar activities that result in the release of harmful gasses such as carbon dioxide and methane. Human activity is therefore considered by researchers as the primary cause of global warming and climate change.
Impact of Climate Change and Global Warming
The IPCC report (2007) on the impact of climate change and global warming identifies the impacts, vulnerabilities, and modes of adaptation to global warming in each sector. The findings show that pollution has a rapidly increasing impact on climate while over exploitation of resources has a continuous impact. These two factors alone are evidence of the extent to which climate change and global warming will influence life and humanity. Mann (2009) notes that the anthropogenic impact of climate change includes rising surface temperature (global warming), changes in the pattern of rainfall, increasing and wide spread incidence of droughts, higher levels of sea water, and natural disasters such as floods and cyclones. These changes in the climatic conditions will affect the ecosystems and consequently will result in reduction of water resources and other infrastructure. It will also adversely affect human health and agriculture. The impact of the greenhouse effect will include extinction of some animal species, reduced food supply. These impacts act as stress on society resulting in conflicts and its consequences such as riots. The extent of the impact will depend on the rate of climate change and the adaptation that occurs to these changes (Mann, 2009).
Climate change refers to the long term changes in weather patterns around the globe. These changes occur as a result of human activities among other things. Global warming is one of the many changes that occur in the climate. Global warming is therefore only a part of climate change. It refers to the increase in the surface temperature of the earth. The average surface temperature has increased by about 0.9o F since 1880. However, it has been increasing at a faster rate over the last decade. The greenhouse effect that is the accumulation of gasses in the earth’s atmosphere is believed to be the primary cause for climate change. Evidence shows that human activity such as burning of fuel, deforestation, and over exploitation of resources are the underlying causes of the greenhouse effect.
Over the last decade, there has been an increasing concern over the changes occurring in the weather patterns. This is because these changes are occurring at a rapid pace and the proportion of harmful gasses in the atmosphere is on the rise. These changes are adversely affecting life on earth. As evidenced by Mann (2009), these changes influence evolution, agriculture, supply of natural resources, and the entire ecosystem. These changes also increase the likelihood of natural disasters such as drought, flood, and cyclones. These predictions have caused researchers, scientists, and astronomers to investigate ways in which the adverse effects can be mitigated.
Although researchers are in agreement about the need for mitigation and adaptation to climate change, there are many differences in opinion as to whether we should adapt to the change or mitigate its effects. Adaptation refers to accepting the changes as inevitable and finding ways to exist in the changed situation. Mitigation on the other hand refers to finding ways to offset the changes and its effects. Research has identified human activity as the primary cause of the greenhouse effect that results in climate change. Mitigation therefore involves steps such as changing human behavior patterns, conservation of resources by educating the public in their use, controlling population with a view to reducing the need for resources, and recycling of resources. Who is responsible for affecting these steps and the ways in which mitigation efforts would be implemented is a matter for further research.
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