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Hot Politics at Jasper Ridge: Is Global Climate Change Really Dangerous?
By: | Saturday, June 7th, 2008Hot Politics at Jasper Ridge
Is global climate change really dangerous?
by Devarati Mitra
What do you do when the political leaders of the most influential nation in the world disagree with the majority of the scientific community about an impending global crisis? This is the question facing ecologists at research institutions throughout the United States and around the world. While there is a general consensus that the global climate has been changing and temperatures have increased on average by about one degree Celsius since the Industrial Revolution, there is still a raging debate about the implications of this finding between the majority of the scientific community and the majority of the American political leadership.
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| With a large and diverse ecosystem, Jasper Ridge near Stanford is an ideal place to study the effects of climate change in an isolated environment. |
The majority of the scientific community agrees that global climate change is a very real and potentially dangerous issue but a few scientists argue the problem is overblown. Politicians, particularly those in the current administration, tend to focus on studies by this minority of researchers to argue that major policy changes to reduce the effects of global climate change are not of primary importance. Stanford University is trying to change that trend. Until now, essentially all the studies for both sides of the debate have focused only on one or two factors that could potentially lead to global climate change. As a result, such studies have been accused of flawed experimental design or inconclusive results by the other side. Here, at Stanford, a team of investigators have come together to put to rest some of the controversy by setting up “The Jasper Ridge Global Change Experiment.” This unprecedented study simultaneously examines four variables known to cause climate change, making it the most comprehensive study on global climate change ever conducted.
The most publicized element of global climate change is the changing global temperature. Studies that both sides of the debate support have concluded that global temperatures are on average about one degree warmer than they were a hundred and fifty years ago. On the one hand, one degree hardly seems like a noticeable amount given that the global climate is known to go through cycles of natural warming and cooling and that the current average temperature is still about ten degrees cooler than the warmest average global temperatures prior to the last Ice Age. Yet, on the other hand, one degree begins to sound significantly more dangerous given the realization that the majority of this change has happened within the last twenty years. And already, the effects of melting polar ice, rising sea levels, changing precipitation patters, falling crop yields, greater prevalence of infectious disease and dramatically changing ecosystems is resulting. The political and scientific struggle to deal with these issues have recently come to the forefront of public discourse as can be seen from four successive issues of the prestigious Science magazine published during the end of 2003, all of which discuss the human influence on “the global commons” that make up our world.
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| Studies have shown that atmospheric carbon dioxide has steadily increased over the past 40 years. But some argue that this is part of natural global climate change cycles. |
At the forefront of the field, Stanford’s “Jasper Ridge Global Change Experiment” is addressing many of these ecological issues. Led by Christopher Field of the Carnegie Institution of Washington and Harold Mooney of Stanford University and conducted at Stanford’s Jasper Ridge Biological Reserve, the Global Change Experiment was designed to use California grasslands as a model system to investigate the effects of four major components of global change. These are known to be caused, at least partially, by the burning of fossil fuels: elevated carbon dioxide, elevated temperatures, increased precipitation and increased nitrogen deposition.
Grasslands were chosen as the model system because, as Dr. Field notes, “they respond quickly to manipulation of global change factors and they are fully functional ecosystems with a high diversity of plant functional types.” By choosing such a responsive system it is possible to see experimental effects within several years instead of waiting for several decades, as would be the case in an ecosystem such as a forest.
The four variables being studied were chosen based on an understanding of fossil fuel burning industries and the greenhouse effect. The variable of elevated carbon dioxide levels was chosen because industrial burning of fossil fuels involves the process of adding oxygen to hydrocarbons which produces carbon dioxide as a bi-product released into the air. The variable of elevated temperatures was chosen because the industries that burn fossil fuels often release other gases such as water vapor, methane, nitrous oxide or other man-made products like choloroflurocarbons (CFCs). These gases allow sunlight to enter the atmosphere unimpeded but tend to absorb the radiation that is reflected back towards space, trapping heat in the atmosphere. The variable of increased precipitation was chosen because, as Christopher Field notes, “warmer climate evaporates more water from the oceans. This needs to fall somewhere” and results in increased rain or snow. Field also explains that the variable of increased nitrogen deposition was chosen because “nitrogen deposition results from the fact that essentially all internal combustion engines oxidize a small amount of atmospheric nitrogen, while they are burning fuel.” This results in increased NO2 in the atmosphere which can either be oxidized to nitric acid which will fall as acid rain or be transferred directly to leaves and soil through a process known as dry deposition.
The effects of the four variables of carbon dioxide, temperature, precipitation and nitrogen deposition were studied by examining small grassland plots having every possible combination of either natural ambient levels or artificially elevated levels of each variable. Since there are four variables that are either ambient or elevated being studied, there are sixteen different combinations of possible treatments (all elevated, all ambient, various combinations of elevated and ambient). The end result is a set of 128 miniature ecosystems that can be studied in terms of plant growth, carbon deposition below-ground, water and nutrient availability and changes in species composition.
After three years, the Global Climate Change study’s results were sufficiently exciting to be published in the December 6, 2002 issue of the prestigious Science magazine. The results included the discovery that previous similar global change studies had been far oversimplified because they had only examined one variable at a time. Interestingly, the Jasper Ridge study showed that an ecosystem’s response to multiple global changes was not a simple combination of responses to individual global change factors. Given that the reality of global climate change is that multiple variables act at the same time this finding brings into question how applicable are the conclusions of most previous studies that examine only one thing at a time.
One specific example that illustrates the importance of examining the environment’s response to multiple variables at the same time can be seen in the conclusions regarding plant growth in response to climate change. The Jasper Ridge study found that when everything except carbon dioxide was at elevated levels, plant growth almost doubled. This result corresponded to the consensus among scientists who believe global climate change is overblown. These scientists argue that nature is able to adjust to changes in the environment; in this case increased nitrogen, water and temperatures are compensated for by changes in vegetation. The Jasper Ridge study, however, showed that this result was not the whole story. If all four variables being studied are elevated (ie-nitrogen, water, temperature and carbon dioxide) plant growth increases by less than half of what the skeptics of global climate change believe. This shows that in the real world, nature will not be able to adequately compensate for man-made environmental changes.
An extension of this point that contradicts many of the global climate change skeptics was the finding that at various increasing levels of carbon dioxide, plant growth does not compensate by increasing proportionally (or even significantly) in response. Given that we release 8 billion tons of carbon dioxide each year through deforestation and the burning of fossil fuels, politicians have been relying on data from other single-factor climate change studies which suggested that increased CO2 levels are not as significant as some have claimed because plants simply would take-up more of the gas and produce more biomass in the normal photosynthetic pathway. The Jasper Ridge study was able to show that in a more realistic system where precipitation, temperature and nitrogen deposition was also increased, there was no large change in carbon storage. Even worse, as CO2 increases, the nutritional quality of plants seems to decrease. In other words: the climate change problem is not going to solve itself and action needs to be taken.
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| Contrary to some studies, work at Jasper Ridge shows that climate change is definitely a valid concern. |
While the Bush administration has acknowledged the existence of global climate change and has suggested the possible necessity of taking action to lessen the human impact, there has been little direct governmental action. Currently the administration’s policy stands as a “voluntary public-private partnership” to try and reduce emissions which contribute to global warming. While some companies have made strides to reduce their emissions as a part of this program, the vast majority are entirely free to ignore the administration’s gentle guidelines. Considering the US accounts for almost 20 percent of the world’s man-made greenhouse emissions and given the Jasper Ridge Global Climate Change Project’s results, in conjunction with the results by countless other ecologists, it seems somewhat short-sighted not to take more stringent action in reducing the emissions of industries which burn fossil fuels. No matter how much politicians would like to quote the small minority of single-factor scientific studies which have come out claiming that global climate change is not a major problem, the preponderance of evidence by the Stanford Jasper Ridge study and by the majority of the scientific community in general, provide evidence for the belief that a massive environmental transformation will result from global climate change. There is only one real solution: science and politics needs to come together in order to implement some real, significant policy modifications.
Topics: Ethics, Environment, and Society, Volume 2, Issue 1 |
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