Global Warming: An Overview of Theoretical Causes and Effects

It has been almost impossible in the past decade to avoid media mention of the issue of global warming. It seems as though it is impossible to watch an hour of the evening new or open a newspaper without at least a brief mention of some aspects of the global warming issue, sometimes in a hopeful but more often in a dire and depressing tone. The recent debacle concerning a batch of stolen email that suggested climate scientists were inflating or even making up the global warming scare has only increased the attention being paid to global warming. Though the email fervor has died down somewhat, as have the accusations that the emails disprove global warming theory (which they don’t), it remains clear that global warming is a vital issue in our times, environmentally and politically.

The politics of global warming can be seen in the machinations of the election system and general political activity in the United States. President Bush was roundly criticized by many individuals both here in the United States and abroad for his refusal to adhere to Kyoto protocols and his general avarice in the face of environmental destruction. President Obama made the environment a large part of his platform, especially after the flippant and cavalier Sarah Palin joined the opposition’s campaign; though the issue was reduced to little more than invective rhetoric and talking points, the fact that it had become such a major part of the general political debate in this country signal both the significance and the controversy of the issue. Global warming has become, rightly or wrongly, one of the most pressing scientific and political questions of the day (WGW 2009).

Global warming is still questionable, too, though many take it as a foregone conclusion. The fact is, there is never anything that is one hundred percent certain in science, and global warming is far from the most certain of scientific theories. Though there is a majority consensus in the scientific community as to the realities of global warming and its human causes, there is not a full agreement from all scientific corners, and no amount of consensus or agreement is the same as fact. The idea of global warming and its human causes cannot really be considered a fact, then, but rather an educated and well-evidenced guess. Even though global warming is not a fact, however, a consideration of its possible effects warrants an investigation of global warming, its causes, and its possible solutions.

The Way Global Warming (Might) Work

Global warming is believed to be the result of what has been dubbed the “greenhouse effect.” Greenhouses, of course, are structures made of glass or plastic that allow sunlight and heat to enter the greenhouse, but don’t allow for its release and so trap it inside so as to create the proper environment for growing certain plants. Scientists believe that certain gases in our atmosphere, particularly carbon dioxide, can behave in a similar way, allowing light and heat from the sun to enter the atmosphere but not allowing for its release back out into space (Willetts 2008). This means that the more carbon dioxide and other greenhouses gases existed in the atmosphere, the more heat could be expected to be trapped in the Earth’s atmosphere. An increase in these atmospheric gases would translate to an increase in the Earth’s temperature, and that is what might be happening (Willetts 2008).

Measurements of carbon dioxide, taken both directly from the atmosphere and through other sophisticated indirect measurement techniques such as ice core samples, show that carbon dioxide levels in the atmosphere began a steep climb at about the same time human industrialization started (zfacts 2007). The Industrial Age has been marked by, amongst other things, a huge increase in the amount of human pollutants — including carbon dioxide and other greenhouse gases — into the environment. The correlation between the known (or rather estimated) human release of carbon dioxide and the measured increase of atmospheric carbon dioxide is huge, making it very probable that human activity in the past two centuries has been primarily responsible for the increase of carbon dioxide in the atmosphere (zfacts 2007). If increased greenhouse gases cause global warming, humans are almost certainly behind the problem.

Human Causes of Global Warming

The predominant source of excess carbon dioxide being released into the atmosphere by human activity comes from the burning of fossil fuels. These fuels come from a variety of sources, but all are called “fossil fuels” because they are the result of millennia of compression under the Earth’s surface working on organic material — living organisms that dies thousands of years ago. Oil and all of its products as well as coal and even natural gas (though it is much cleaner than the other fossil fuels) are all the result, and burning these fuels releases carbon dioxide — one remnant of organic material — into the atmosphere and creating what is believed to be the primary cause behind global warming (NASA 2009). Human beings in industrialized countries burn these fuels almost constantly.

Cars are a familiar source of carbon emissions, and it is true that they release a lot of carbon dioxide into the atmosphere. This is why a push to develop more efficient passenger vehicles has been a major part of most “green” agendas aimed at halting global warming. Cars, however, are only the tip of the iceberg; other vehicles — especially those used for shipping — release far more greenhouse gases per mile traveled, and the shipping industry also puts many more miles on their vehicles on a constant basis. What this means is, making greener cars won’t be sufficient or even all that beneficial (though it certainly wouldn’t hurt) in making a world less prone to global warming (zfacts 2007). Almost all of human commerce in the industrialized world is driven by fossil fuels, and the global market only makes it worse.

The production of energy is an even bigger contributor to the problem than the shipping industry, though luckily there are more possible alternatives in this area as well (Willets 2008; NASA 2009). A large number of electricity plants are powered by coal, and though coal technologies are becoming cleaner they are still among the dirtiest of fossil fuels not only in terms of greenhouse gas emissions but also in other pollutants. Though electricity is often considered a green alternative in cars, it is only truly “green” if the source of the electricity is “green” as well — otherwise the exhaust from a gasoline or diesel engine is simply displaced to the coal-burning electricity plant. The amount of electricity consumed in the industrialized world is huge — it is used by every business in one way or another, it allows us to see at night, to watch television, to surf the web, and even to write papers on our laptops. This consumption of energy is a direct contribution to greenhouse gases.

The real problem with the release of carbon dioxide and other gases is their longevity — they can be expected to remain in the atmosphere for a century after they are released, meaning we have already created a problem it is impossible to correct (though we can keep it from getting worse) (Willetts 2008). To make matters even worse, deforestation is both releasing more carbon dioxide and destroying one of the simplest means for correcting the problem (Howden 2007). Trees, as organic material themselves, are huge stores of carbon, and given that they use carbon dioxide in the same way that humans use oxygen means that trees actually work to take carbon dioxide out of the atmosphere. When trees die, they release this carbon; nature ahs a great capacity to reabsorb this carbon normally, but commercial logging and deforestation has led to a huge increase in the amount of carbon being released and an accompanying decrease in the amount nature can reabsorb.

Problems with Current Global Warming Theories

It was stated previously that global warming is not a fact, and to be certain much of the information — or at the very least the conclusions — that have been drawn in this paper are matters of contention. First of all, the warming trend that has been measured and confirmed by many scientists has also been disputed by others, who point out the large degree of estimation necessary in measuring the overall temperature of the Earth (JunkScience 2007). The rise of one degree Celsius that has been supposedly measured over the past century is not statistically significant enough to be evidence of a true warming trend, some claim. In addition, any warming that may exist is impossible to trace to human causes.

It is true that no causal link between human activities and global warming has or likely ever could be made with any scientific certainty, and there are other considerations in the global warming issue that make hasty conclusions something to be avoided. There would be massive economic and therefore political repercussions if drastic limitations on carbon emissions and transitions to alternative energy sources was mandated. These effects would be unfairly harsh on developing nations, who had little to do with creating the problem; this is one of the reasons that recent international talks in Copenhagen have stalled (WGW 2009). Not only would these countries not be able to develop as quickly and have healthier populations and more stable governments, but industrialized nations would also see negative economic impacts, making many wary of making any major transitions without a more certain analysis of the problem of global warming, and of a human cause behind it.

The Effects of Global Warming

Even if global warming isn’t real, or if human emissions aren’t behind it, the possible consequences and tangential downsides to the continued release of carbon dioxide and an increase in global warming warrant taking steps to find cleaner fuels and sources of energy. Warmer temperatures would lead directly to more frequent and more violent storms and hurricanes, as adding heat to the weather system adds both energy and moisture to it (NRCD 2009). The recent spate of especially violent hurricanes could be an early result of global warming, some scientists claim, and it is virtually undisputed that warmer overall temperatures would lead to more violent storms occurring more frequently (NRCD 2009).

Not only would existing weather grow more violent and more wet, but there could also be devastating changes to the Earth’s overall weather patterns. The world’s weather patterns are largely a product of the temperatures of the oceans and the surrounding air, and when these temperatures increase there could be large and somewhat unpredictable changes in these weather patterns (NRCD 2009). Some areas might actually become cooler than they are now, while temperatures would rise in others; lack of rainfall in one place or a sudden inundation in another could drastically change landscape and lead to the irreversible destruction of existing ecosystem (NRCD 2009). The weather isn’t generally thought of as such a powerful force, but especially in the long-term it has the potential to completely reshape the world in which we live, and global warming has a formative effect on weather.

The rising ocean levels that are expected as a result of the melting polar ice caps are another way in which our world might be transformed by global warming (WGW 2009). Not only will this lead to the flooding of many islands and coastal areas decimating many ecosystems and large human populations, but this will also have an immediate effect on the weather of newly flooded regions (NRCD 2009). The increased flooding of islands and continents and the encroachment of the world’s oceans will also mean that there is simply less land to go around, and resources will become scarcer (NRCD 2009). There are therefore very immediate physical threats and long-term political and social effects of global warming and its consequences, all of which must be fully analyzed and considered when deciding whether or not to act on the possibility of global warming.

Human beings, of course, will not be the only species affected by global warming. Many animals have already begun to shift the regions they inhabit, seemingly in response to global warming (Bryner 2006). As temperatures rise, ecosystems change, and even subtle changes can have large ripple effects. The shifting animal populations that have been noted in some regions have been correlated to global warming figures by computer models, suggesting that warming temperatures are the primary if not sole reason for certain habitat shifts (Bryner 2006). The warming would not only cause habitat shifts, but it could also cause the extinction of many species. Some simply would not be able to adjust to new temperatures and ecosystems, and others would lose in the fiercer battle for resources that would be the natural result of diminishing ecosystems and more crowded living space.

Evidence for Global Warming

Not only would the effects of global warming, if it exists, be devastating, but the fact that many of the predicted effects are beginning to occur provides some evidence that the problem is real despite a lack of scientific agreement. The changing habitation regions of animals were observed and measured before a correlation to global warming was hypothesized, yet the data still seems to fit (Bryner 2006). Average temperature recordings taken by a large number of scientists at points all over the globe, though disputable in their accuracy, do show a warming trend, and the increased rate of melting of the polar ice caps seems to confirm these measurements (NASA 2009). Weather disturbances are harder to link to global warming, but might be another part of the effects.

Though this evidence is still not truly conclusive, it is very persuasive both in its abundance and in the extremity of its predictions. There are no certainties in science, so it will never be “proved” that global warming is happening, and it will be even more difficult to objectively assert that human beings were the cause behind any warming that does occur. But despite this lack of certainty — or perhaps because of it — the large scientific consensus regarding global warming and the amount of evidence supporting this consensus makes it a highly probable reality. Certainly, despite the fears of economic and political fallout that might occur from shifting the world away from fossil fuels, the projected effects of global warming are even more extreme, and more of a cause for action.

Conclusion

Global warming is not a fact, but there is a high degree of scientific probability that the planet is indeed getting warmer, and that human activity is at the root of this temperature change. Even if global warming does not exist, however, becoming more responsible with the way in which we use our resources and manage the by products of our consumption certainly isn’t a bad thing. There are economic benefits to going green; renewable energy is much cheaper, once the technology for it is in place, so the reduction of emissions correlates to an increase in cash. Also, carbon dioxide is a known pollutant and is bad for human health and the environment in a variety of ways. Whether or not reducing emissions ahs anything to do with global warming, developing cleaner technologies to keep our air wand water clean is a good thing.

References

Bryner, J. (2006). “Climate Change Has Animals Heading for the Hills.” LiveScience. Accessed 13 December 2009. http://www.livescience.com/environment/061214_animals_retreat.html

Howden, D. (2007). “Deforestation: The hidden cause of global warming.” The independent 14 May. Accessed 12 December 2009. http://www.independent.co.uk/environment/climate-change/deforestation-the-hidden-cause-of-global-warming-448734.html

JunkScience (2007). “The real “inconvenient truth.” JunkScience.com. Accessed 13 December 2009. http://www.junkscience.com/Greenhouse/

NASA. (2009). “Global warming.” World Book at NASA. Accessed 13 December 2009. http://www.nasa.gov/worldbook/global_warming_worldbook.html

NRDC. (2009). “The consequences of global warming on weather patterns.” Natural Resources Defense Council. Accessed 13 December 2009. http://www.nrdc.org/globalWarming/fcons/fcons1.asp

Willetts, H. (2008). “Global warming — an overview.” BBC News. Accessed 13 December 2009. http://www.bbc.co.uk/weather/features/global_warming1.shtml

Worldview of global warming. (2009). Accessed 13 December 2009. http://www.worldviewofglobalwarming.org/pages/news.html

zfacts (2004). “CO2: Global Carbon Dioxide Levels Linked to Human Activity.” Accessed 12 December 2009. http://zfacts.com/p/194.html