It is hard nowadays to open a newspaper or turn on a TV without hearing about global warming. Whether you are a science geek or not, I'd all like to share with you a debate regarding global warming by presenting different views from two articles that I find absolutely fascinating in a less technical way. Hopefully, it would help you gain better understanding of one of the hotest topics in the 21 century and become more interested in science.
The global warming controversy includes two major levels. First, whether global warming is real and how bad it could be. That is, if the rising temperature is unprecedented or within normal climatic variations and if it is necessary to take actions to control it. Second, if the warming trend does exist, then is it mainly human-caused or simply a combined form of effects of natural activities? In the opinion piece “Time to Act” *, published on April 30th, 2009 in Nature Journal, the author conveys his opinions and solutions to global warming. The author sees the possible dangers and effects of global warming and argues that, in order to prevent our planet from being pushed into the “danger zone” due to the excessive emission of greenhouse-gases that drives up the global temperature, countries all over the world need to reach and commit to an international climate agreement that regulates the emission of carbon. In the mean time, they need to conduct researches and develop technologies to cool Earth; and they need to do it right now. The author acknowledges human contribution to global warming, pointing out that if the current emission rate continues, humankind will “have emitted a trillion tons of carbon into the atmosphere well before 2050”, which may destabilize the Earth system and bring catastrophic results. A recent study shows that even a substantial reduce of carbon may not significantly decrease the temperature; the author suggests, if that is the case, nations should, besides simply cutting the emission of CO2, start “actively removing CO2 from the atmosphere”. In addition, global leaders need to develop necessary technologies that can “provide an escape hatch if the climate ever does reach a tipping point.” In other words, if the cut of greenhouse gas could not effectively slow down the warming trend, countries need to at least have the techonology, to reduce the temperature. Shading the earth from the sunlight would be an example. Now matter what methods could be effective, there is no question that it is the time for human interventions to keep our planet earth from heating up.
Many skeptics, on the other hand, find the global warming theory doubtful. In the article “Does CO2 really drive global warming”, Ohio State professor Robert Essenhigh argues that human-caused emissions only account for a comparatively small amount (less than 5%) of carbon dioxide in the atmosphere, and carbon dioxide is not the cause of global warming; he states that it is the rising temperature that increases the amount of carbon dioxide -- not the other way around -- and argues that global warming is just a natural oscillating cycle, in which the temperature may reach a peak and begin to decrease in 10 years. Essenhigh uses many scientific statistics and researches to support his views. He cites a report from the Intergovernmental Panel on Climate Change and concludes that the 5-6 billion tons of carbon dioxide emitted each year by human are only a small proportion of the 90 billion tons of carbon in the atmosphere. Thus, he doesn’t believe that “man-made carbon dioxide can be driving the rising temperature”, which, I think, makes perfect sense. He also employs evidences from historical data and models. For example, he examines a data and finds that “global temperature has been oscillating steadily, with an average rising gradually, over the last one million years -- long before human industry began to release carbon dioxide into the atmosphere”. Moreover, after calculating the concentration of water and carbon dioxide, he finds that water（another “heat” absorbing gas), on average, is 25–30 denser than CO2. This result leads him to believe that carbon dioxide is too insignificant to result in global warming.
Although it depends on your personal values which argument you support, I find, as far as convincing and effectiveness is concerned, Essenhigh’s arguments is much more compelling. I think the best way to present a science argument is to employ sufficient facts, numbers and respectful documents. As Essenhigh says himself, "If there are flaws in these propositions, I'm listening. But if there are objections, let's have them with the numbers.” Being a science geek myself, I know that our planet did survive periods when the average temperatures were much higher that it is today and oscillating is very likely the overall pattern of temperature. In the mean time, however, I’d rather wish that global warming is human-caused, because that means we would at least have opportunities to change it for good. If it is a simply natural process, that implies that there is nothing we can do but waiting for itself to change. But what if it doesn’t change? What if it is just our destiny?
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