Topic: Global warming is said to be caused by humans. Do you agree? And, what is the role of an individual in conserving the environment?
Though I will not exactly answer these questions for I am not an expert in the controversies of global warming, I will nevertheless share some info I have while reading on global warming issues. So below is a bit about global warming. And I must admit that having had a couple of global warming articles read, I personally find global warming a difficult subject to talk about.
Below is a part of IPCC's dialogue with John Christy on global warming. IPCC is the abbreviation for Intergovernmental Panel on Climate Change and John Christy is a professor of atmospheric science and director of the Earth System Science Center at the University of Alabama in Huntsville and a contributor to several IPCC.
In the dialogue (below), IPCC questions John Christy on the difference in the amount of greenhouse gas increase caused by human activities and that of natural sources. John Christy replies to IPCC saying that the difference caused by both human activities and natural sources is yet unknown, indirectly telling them that the causes of global warming is therefore unidentified. Read on for dialogue...
IPCC: If global temperatures are increasing, to what extent is the increase attributable to greenhouse gas emissions from human activity as opposed to natural variability or other causes?
John Christy: No one knows. Estimates today are given by climate model simulations made against a backdrop of uncertain natural variability, assumptions about how greenhouse gases affect the climate, and model shortcomings in general. The evidence from our work (and others) is that the way the observed temperatures are changing in many important aspects is not consistent with model simulations.
- Global Warming Controversy
Like Christy, there are other scientists, too, who believe the cause of global warming is unknown. Some other scientists though choose to think that the idea of humans as primary cause to global warming has yet to be ascertained. In Roberts & Street-Perrott (1994) it is stated that a few scientists doubt as to whether global warm phase truly occurred at all, thinking even if it did, its magnitude was very much less than that projected for future greenhouse-gas induced warming.
For more information on scientists opposing the mainstream scientific assessment of global warming, click here.
So given some doubts and opposition to the causes of global warming from scientists themselves, what actually really creates global warming, I truly wonder.
- What Is Global Warming?
It is said that global warming (as according to mainstream scientific assessment) is defined as the increase in the average temperatures of the Earth's near-surface air and oceans in recent decades. It has been studied that during the past century, global average air temperature near the Earth's surface rose about 0.74 ± 0.18 °C (1.3 ± 0.32 °F).
The Intergovernmental Panel on Climate Change (IPCC) has even concluded that most increase in globally averaged temperatures since the mid-20th century is very likely the cause of the increase in anthropogenic greenhouse gas concentrations.
And rapid increase in global temperature can cause other changes, which includes the rise in sea level, changes in the amount and pattern of precipitation resulting in floods and drought, as well as in the frequency and intensity of extreme weather events, to occur.
Other effects however may include changes in agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors.
Having said all these however, global warming, according to some scientists, is only a theory. Despite being just a prediction, it is also believed that global warming will keep on going in the years to come.
- Causes of Global Warming
Global warming is predicted to occur because of the rise in average air temperature near the Earth's surface during the past century. The increased emission of the so-called "greenhouse gases" or otherwise known as the anthropogenic greenhouse gas concentrations is expected to warm the surface and lower atmosphere by increasing the greenhouse effect.
Increased greenhouse gases and the greenhouse effect is feared to contribute to an overall warming of the Earth's climate, leading to a global warming (even though some regions may experience cooling, wetter weather, while the temperature of the planet on average would rise). The most important of the greenhouse gases is water vapour, carbon dioxide and methane. These gases are thought to lead to some negative impacts to human and the environment.
Methane, increasing in the atmosphere more rapidly than carbon dioxide, is said to derive from sources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel production. Most of the world’s rice, and all of the rice in the United States, is grown on flooded fields. When fields are flooded, anaerobic conditions develop and the organic matter in the soil decomposes, releasing methane to the atmosphere, primarily through the rice plants.
Carbon dioxide, on the other hand, have risen principally because of fossil-fuel burning since the nineteenth century, with reduced photosynthesis due to deforestation as an important secondary cause.
While methane and carbon dioxide are said to be products of the human activities (and therefore direct causes to global warming), water vapour, however, is not. Water vapour is a naturally occurring greenhouse gas and accounts for the largest percentage of the greenhouse effect, between 36% and 90%.
Water vapor content of the troposphere, however, is easily increased when the atmospheric temperature is increased by greenhouse effect. Simultaneously, greenhouse effect is caused by anthropogenic gases.
- So, is global warming caused by humans?
I still don't know actually. And what makes it even confusing is this: Houghton et al,. (1990) once stated that the most important greenhouse gases, that is methane, carbon dioxide and water vapour, are after all naturally present in the atmosphere and without them the global mean temperature would be lower by around 33 degrees Celsius!
- So?
Having said all of the above, I really wonder what if humans are the real cause to global warming and global warming really does occur? Do we get anything out of blaming human activities for causing such phenomenon??
- Individual's role to conserving the environment
As for individual's role to conserving the environment, well, I think it is perhaps best to keep oneself informed on the what not’s to global warming, such as what not to do...(I got really lazy and sleepy here), and/or understand why the earth surface keeps warming and how to slow it down...Or perhaps becoming an active member in the many environmental organizations available worldwide can possibly help conserve the environment. I think. I am in some environmental organizations though not an active member at all (because I'm here in capitalist Singapore. Shit.). So what do you think?
Doze off...
References (incomplete):
Global Warming: The Causes, Available [Online]: http://www.ecobridge.org/content/g_cse.htm
Annual Greenhouse Gas Emissions By Sector, Global Warming Awareness, Available [Online]: http://www.globalwarming.org.in/
Roberts N. & Street-Perrott F. A.,1994 in The Changing Global Environment by Roberts, N.,
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