A Synthesis of Ideas Related to the Global Warming Controversy

Edited by: Paul Jacob

February 15th 2007

What is Global Warming?

Definition: Global warming is the observed increase in the average temperature of the earth's atmosphere and oceans in recent decades and its projected continuation into the future.

The earth’s average near-surface atmospheric temperature rose 0.6 ± 0.2 °C (1.1 ± 0.4 °F) in the 20th Century. The prevailing scientific opinion on climate change is that “most of the warming observed over the last 50 years is attributable to human activities.” That being said, without greenhouse gases, the earth would be 33 °C colder than it currently is, which is undesirable to all concerned – climate change activists and global warming nay-sayers alike.

Though much of the global warming effect is created by the presence of water vapor, humans also play a part. The increased amounts of carbon dioxide (CO2), methane (CH4), and Nitrous Oxide (N2O), are the primary causes of the human-induced component of warming. They are released by the burning of fossil fuels, land clearing, agriculture, etc. and lead to an increase in the greenhouse effect. The percentage breakdown of each major human-induced greenhouse gas for the year 2000 is shown in the chart below:

On the other hand, it is important to keep in mind that there are fundamentally non-human aspects to global warming, including but not limited to: water vapor, which may account for some 70-95% of global warming related causes, or even more; but that will be discussed in more depth later in this report.

If Global Warming is True, What’s the Downside?

An increase in global temperatures can in turn cause other changes, including a rising sea level and changes in the amount and pattern of precipitation. These changes may increase the frequency and intensity of extreme weather events, such as floods, droughts, heat waves, hurricanes, and tornados. Other consequences include higher or lower agricultural yields, glacial retreat, reduced summer streamflows, species extinctions, and increases in the ranges of disease vectors. Warming is expected to affect the number and magnitude of these events: however, it is difficult to connect particular events to global warming. Although most studies focus on the period up to 2100, warming (and sea level rise due to thermal expansion) is expected to continue past then, since CO2 has a long average atmospheric lifetime.

Remaining scientific uncertainties include the exact degree of climate change expected in the future, and especially how changes will vary from region to region across the globe. A hotly contested political and public debate has yet to be resolved regarding whether anything should be done, and what could be cost-effectively done to reduce or reverse future warming, or to deal with the expected consequences.

The Bhutan-Himalaya Glaciers (aerial photo shows forming glacial lakes)

What is the Greenhouse Effect?

Definition: The warming of the atmosphere by the trapping of longwave radiation being radiated to space.

The term 'greenhouse effect' originally came from the greenhouses used for gardening, but it is a misnomer since greenhouses operate differently. A greenhouse is built of glass; it heats up primarily because the sun warms the ground inside it, which warms the air near the ground, and this air is prevented from rising and flowing away. The warming inside a greenhouse thus occurs by suppressing convection and turbulent mixing. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature will drop considerably. It has also been demonstrated experimentally: a "greenhouse" built of rock salt (which is transparent to IR) heats up just as one built of glass does. Greenhouses thus work primarily by preventing convection; the atmospheric greenhouse effect however reduces radiation loss, not convection. It is quite common, however, to find sources that make the "greenhouse" analogy. Although the primary mechanism for warming greenhouses is the prevention of mixing with the free atmosphere, the radiative properties of the glazing can still be important to commercial growers. With the modern development of new plastic surfaces and glazings for greenhouses, this has permitted construction of greenhouses which selectively control radiation transmittance in order to better control the growing environment.

Concerning the greenhouse effect, the earth naturally absorbs and reflects incoming solar radiation and emits longer wavelength terrestrial (thermal) radiation back into space. On average, the absorbed solar radiation is balanced by the outgoing terrestrial radiation emitted to space. A portion of this terrestrial radiation, though, is itself absorbed by gases in the atmosphere. The energy from this absorbed terrestrial radiation warms the earth’s surface and atmosphere, creating what is known as the “natural greenhouse effect.” Without the natural heat-trapping properties of these atmospheric gases, the average surface temperature of the earth would be about 33 °C lower. The following Diagram shows how the greenhouse effect works.

Greenhouse Gases

Greenhouse gases (GHGs) are gaseous components of the atmosphere that contribute to the greenhouse effect. Some greenhouse gases occur naturally in the atmosphere, while others result from human activities. Naturally occurring greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Certain human activities, however, add to the levels of most of these naturally occurring gases.

The major natural greenhouse gases are water vapor, which causes about 36-70% of the greenhouse effect on earth (not including clouds); carbon dioxide, which causes 9-26%; methane, which causes 4-9%, and ozone, which causes 3-7%. It is not possible to state that a certain gas causes a certain percentage of the greenhouse effect, because the influences of the various gases are not additive (the higher ends of the range quoted are for the gas alone; the lower ends, for the gas counting overlaps). Other greenhouse gases include, but are not limited to: nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, perfluorocarbons, and chlorofuorocarbons (see IPCC list of greenhouse gases).

The major atmospheric constituents (nitrogen, N2 and oxygen, O2) are not greenhouse gases. This is because homonuclear molecules such as N2 and O2 neither absorb nor emit infrared radiation as there is no net change to the dipole moment of these molecules.

Two Differing Points of View: CO2 as the most important Greenhouse Gas vs. Water Vapor as the most important Greenhouse Gas

CO2 is the Most Important Greenhouse Gas

Some scientific sources and environmental agencies choose to neglect the effects of water vapor as the most prominent greenhouse gas, and instead focus on CO2 as the predominant greenhouse gas. For instance, The Kyoto Protocol – the amendment to the UN Global climate treaty – fails to mention water vapor as a concern and instead focuses on CO2 as the leading emission in the battle against global warming. This seems odd since the protocol’s objective is to eliminate excess degrees of greenhouse gases in the atmosphere in order to quell the Global Warming Phenomenon. From the United Nations Framework Convention on Climate Change website, we can find the following purpose statement for the Kyoto Protocol ratification to the United Nations Global Climate Treaty:

The 1997 Kyoto Protocol shares the Convention’s objective, principles and institutions, but significantly strengthens the Convention by committing Annex I Parties to individual, legally-binding targets to limit or reduce their greenhouse gas emissions. Only Parties to the Convention that have also become Parties to the Protocol (i.e. by ratifying, accepting, approving, or acceding to it) will be bound by the Protocol’s commitments. 168 countries and one regional economic integration organization (the EEC) have ratified the Protocol to date. Of these, 35countries and the EEC are required to reduce greenhouse gas emissions below levels specified for each of them in the treaty. The individual targets for Annex I Parties are listed in the Kyoto Protocol’s Annex B. These add up to a total cut in greenhouse-gas emissions of at least 5% from 1990 levels in the commitment period 2008-2012.

Now, to be fair, the reason why the UN might disregard the effects of water vapor is that this greenhouse gas is not man-made. Moreover, some climate analysts say that the greenhouse gas emissions which are man-made only spur the increase in water vapor; and that in the end, these greenhouse gases (CO2, CH4, Nitrous Oxide, etc.) are responsible for the water vapor increase. This is called Water Vapour Feedback, and is claimed to be a scientific reason for avoiding anthropogenic (human induced) gases all the more. For example, Lonnie Thompson, a climatologist at Ohio State University who studies ice cores and glacier retreat, said, “This research indicates that small changes in temperature, driven by greenhouse gases, put more water vapor into the atmosphere, which drives up the temperature more.”

Furthermore, some scientists claim that water vapor balances itself out because it can reflect both shortwave and longwave radiation from the sun and earth respectively.

This tendency to reflect from both directions would mean that water vapor both prevents and adds to the problem of Global Warming.

2. Water Vapor is the Most important Greenhouse Gas

Other scientists have a different notion of the importance of water vapor in effecting the climate. They believe that the water vapor increases which we have experienced in the past century are the main cause of global warming, and that CO2 effects are more-or-less negligible when compared with water vapor effects.

One scientist – Vladimir Shaidurov of the Russian Academy of Sciences – has established a theory that would relate the increase in water vapor to the catastrophic Tunguska Event on June 30th of 1908, which felled 60 million trees over 2,150 square kilometers of Russian countryside.

The explosion was most likely caused by the airburst of an asteroid or piece of a comet 5 to 10 kilometers (3–6 miles) above the earth's surface. The energy of the blast was later estimated to be between 10 and 20 megatons of TNT, which would be equivalent to Castle Bravo – the most powerful nuclear bomb ever detonated by the US. It is still unclear, however, what the actual cause of the event was, and there is much speculation regarding its origin.

According Shaidurov, the most potent greenhouse gas is water, and it is this compound on which his study focuses. Shaidurov takes this one step further by claiming that only small changes in the atmospheric levels of water, in the form of vapor and ice crystals, can contribute to significant changes in the temperature of the earth’s surface. This far outweighs the effects of carbon dioxide and other gases released by human activities. A 1% rise in water vapour could raise the global average temperature of the earth’s surface by more than 4 degrees Celsius!

As such, Shaidurov has concluded that only an enormous natural phenomenon, such as an asteroid or comet impact or airburst, could seriously disturb atmospheric water levels, destroying persistent so-called 'silver', or noctilucent, clouds composed of ice crystals in the high altitude mesosphere (50 to 85 km). The Tunguska Event was just such an event, and coincides with the period of time during which global temperatures appear to have been rising the most steadily - the twentieth century. There are many hypothetical mechanisms of how this mesosphere catastrophe might have occurred, and future research is needed to provide a definitive answer.

A similar perspective points directly to water vapor as the problem, even outside of catastrophic events. Dr. Tim Patterson – the Professor Geology at Carleston University in Ottawa and notable scholar according to liberal pro-environment websites like sourcewatch.org – is an example of a scientist who goes against the grain of popular views concerning global warming and seems to be lacking in bias. According to the sourcewatch website:

Patterson has proven to be a difficult target for climate change alarmist activists for three reasons: 1) He is a well respected internationally known research scientist with 118 peer-reviewed research publications as of late 2006; 2) He is a research scientist who goes where the science takes him and not where climate change alarmist activists want him to go; and 3) he has been exclusively funded by governmental research agencies such as the Natural Sciences and Engineering Research Council of Canada (NSERC) as well as the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS). Much to his chagrin (especially as he runs a large lab) he has been unable to attract a single dollar from industry or and public relations firms such as APCO Worldwide.

In a recent article in TCS Daily, Patterson discussed the water vapor problem, and the contrary notion, which negates water vapor and focuses on CO2 emissions instead:

The media, special interest groups, and even some government produced literature all report that CO2 is the most important greenhouse gas. I was at the Canadian Museum of Nature a few months ago where a traveling display was set up that clearly, and erroneously I might add, indicated that CO2 was the most important greenhouse gas. The number one greenhouse gas is actually water vapor. It's something like 98 percent, by volume, of all greenhouse gases. I like the way that my colleague, Jan Veizer at the University of Ottawa, a world-renowned expert on the carbon cycle, lists the relative importance of greenhouse gases when he speaks on the topic. He points out that the number one greenhouse gas is water vapor, the number two greenhouse gas is water vapor, the number three greenhouse gas is water vapor, the number four greenhouse gas is water vapor and CO2 is a distant fifth. Of course, this list is somewhat facetious as there is only one type of water vapor. However, he lists the relative importance of greenhouse gases this was to indicate just how insignificant the tiny carbon dioxide cycle is to the water vapor cycle that it piggybacks on. To give you an example of this comparison lets consider the amount of CO2 in the atmosphere. In the 19th Century, when the world was relatively unindustrialized the level of CO2 in the atmosphere stood at around 285 ppm. By 2003 the level of CO2 in the atmosphere, primarily the result of industrialization and land use changes, stood at 376 ppm. The resultant influence on climate has been minimal. Computer models say that this increase in CO2 should have heated the Earth up significantly by this stage. However, very little warming that can be attributed to CO2 has actually occurred.

Greenhouse Gases measured using Ice Core Samples

In order to back up the position that CO2 and other greenhouse gases have the potential to effect climate change, scientists have used ice core samples to study weather patterns in the past.

The most direct method for measuring atmospheric carbon dioxide concentrations for periods before direct sampling is to measure bubbles of air (fluid or gas inclusions) trapped in the Antarctic or Greenland ice caps. The most widely accepted of such studies come from a variety of Antarctic cores and indicate that atmospheric CO2 levels were about 260 – 280µL/L immediately before industrial emissions began and did not vary much from this level during the preceding 10,000 years.

Analysis of the air contained in bubbles in the ice can reveal the palaeocomposition of the atmosphere, in particular CO2 variations. There are great problems relating the dating of the included bubbles to the dating of the ice, since the bubbles only slowly “close off” after the ice has been deposited. Nonetheless, recent work has tended to show that during deglaciations CO2-increases lag temperature-increases by 600 +/- 400 years.

Global Warming Potential

Do you remember how we had various different greenhouse gases that contribute to the greenhouse effect? Well, another aspect to the global warming phenomenon is the fact that different molecules absorb and reflect more longwave radiation than others. For instance, methane (CH4) absorbs and reflects longwave radiation much more effectively than carbon-dioxide (CO2). Therefore, methane creates a greater global warming effect than carbon-dioxide, which means that it has a higher global warming potential. Global warming potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale which compares the gas in question to the same mass of carbon dioxide (whose GWP is by definition 1). A GWP is calculated over a specific time interval and the value of this must be stated whenever a GWP is quoted or else the value is meaningless.

The table for different GWP’s in relation to the most prominent greenhouse gases is given below:

 

Gas Atmospheric

100-year

20-year

500-year

 

Lifetime

GWPa

GWP

GWP

Carbon Dioxide (CO2)

50-200

1

1

1

Methane (CH4)b

12±3

21

56

6.5

Nitrous Oxide (N2O)

120

310

280

170

HFC-23

264

11,700

9,100

9,800

HFC-125

32.6

2,800

4,600

920

HFC-134a

14.6

1,300

3,400

420

HFC-143a

48.3

3,800

5,000

1,400

HFC-152a

1.5

140

460

42

HFC-227ea

36.5

2,900

4,300

950

HFC-236fa

209

6,300

5,100

4,700

HFC-4310mee

17.1

1,300

3,000

400

CF4

50,000

6,500

4,400

10,000

C2F6

10,000

9,200

6,200

14,000

C4F10

2,600

7,000

4,800

10,100

C6F14

3,200

7,400

5,000

10,700

SF6

3,200

23,900

16,300

34,900

Source: IPCC (1996)

a GWPs used here are calculated over 100 year time horizon

b The methane GWP includes the direct effects and thoose indirect effects due to the production of

tropospheric ozone and stratospheric water vapor. The indirect effect due to the production of CO2

is not included.

In order to determine what the effective radiative force of a gas is, the amount of the gas is multiplied by the GWP. This is how we can calculate the percentage effects of greenhouse gases with respect to global warming. As such, the main greenhouse gases are represented by percentage below:

Neglecting the effects of water vapor, the distribution of CO2 to the other greenhouse gases changes from 3% to approximately 70% as shown below:

Carbon Dioxide

Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. It is often referred to by its formula CO2. It is present in the earth’s atmosphere at a low concentration and acts as a greenhouse gas. In its solid state, it is called dry ice. It is a major component of the carbon cycle.

As of January 2007, the earth's atmospheric CO2 concentration is about 0.0383% by volume (383 ppmv) or 0.0582% by weight. This represents about 2.996×1012 tonnes, and is estimated to be 105 ppm (37.77%) above the pre-industrial average.

Despite its small concentration, CO2 is a very important component of earth's atmosphere, because it absorbs infrared radiation at wavelengths of 4.26 µm (asymmetric stretching vibrational mode) and 14.99 µm (bending vibrational mode) and enhances the greenhouse effect.

The Carbon Cycle

Definition: The organic circulation of carbon from the atmosphere into organisms and back again.

The cycle is usually thought of as four major reservoirs of carbon interconnected by pathways of exchange. The reservoirs are the atmosphere, the terrestrial biosphere (which usually includes freshwater systems and non-living organic material, such as soil carbon), the oceans (which includes dissolved inorganic carbon and living and non-living marine biota), and the sediments (which includes fossil fuels). The annual movements of carbon, the carbon exchanges between reservoirs, occur because of various chemical, physical, geological, and biological processes. The ocean contains the largest active pool of carbon near the surface of the Earth, but the deep ocean part of this pool does not rapidly exchange with the atmosphere.

Carbon is taken from the atmosphere in several ways:

· When the sun is shining, plants perform photosynthesis to convert carbon dioxide into carbohydrates, releasing oxygen in the process. This process is most prolific in relatively new forests where tree growth is still rapid.

· At the surface of the oceans towards the poles, seawater becomes cooler and more carbonic acid is formed as CO2 becomes more soluble. This is coupled to the ocean's thermohaline circulation which transports dense surface water into the ocean's interior.

· In upper ocean areas of high biological productivity, organisms convert reduced carbon to tissues, or carbonates to hard body parts such as shells and tests. These are, respectively, oxidized (soft-tissue pump) and redissolved (carbonate pump) at lower average levels of the ocean than those at which they formed, resulting in a downward flow of carbon.

· The weathering of silicate rock. Carbonic acid reacts with weathered rock to produce bicarbonate ions. The bicarbonate ions produced are carried to the ocean, where they are used to make marine carbonates. Unlike disolved CO2 in equilibrium or tissues which decay, weathering does not move the carbon into a reservoir from which it can readily return to the atmosphere.

Carbon can be released back into the atmosphere in many different ways:

· Through the respiration performed by plants and animals. This is an exothermic reaction and it involves the breaking down of glucose (or other organic molecules) into carbon dioxide and water.

· Through the decay of animal and plant matter. Fungi and bacteria break down the carbon compounds in dead animals and plants and convert the carbon to carbon dioxide if oxygen is present, or methane if not.

· Through combustion of organic material which oxidizes the carbon it contains, producing carbon dioxide (and other things, like water vapor). Burning fossil fuels such as coal, petroleum products, and natural gas releases carbon that has been stored in the geosphere for millions of years. This is the major reason for the current rise in atmospheric carbon dioxide levels.

· Production of cement. Carbon dioxide is released when limestone (calcium carbonate) is heated to produce lime (calcium oxide), a component of cement.

· At the surface of the oceans where the water becomes warmer, dissolved carbon dioxide is released back into the atmosphere.

· Volcanic eruptions and metamorphism release gases into the atmosphere. These gases include water vapor, carbon dioxide and sulfur dioxide. The carbon dioxide released is roughly equal to the amount removed by silicate weathering; so the two processes, which are the chemical reverse of each other, sum to roughly zero, and do not affect the level of atmospheric carbon dioxide on time scales of less than about 100,000 yr.

Controversy?

The global warming controversy is an ongoing dispute about the effects of humans on global climate, and about what policies should be implemented to avoid possible undesirable effects of climate change.

The current scientific consensus on climate change is that recent warming indicates a fairly stable long-term trend, that the trend is largely human-caused, and that serious damage may result if steps are not taken to halt the trend. Mainstream scientific organizations worldwide (Royal Society, American Geophysical Union, Joint Science Academies, Intergovernmental Panel on Climate Change, American Meteorological Society, and American Association for the Advancement of Science (AAAS)) concur with the assessment that “most of the observed warming over the last 50 years is likely to have been due to the human-caused increase in greenhouse gas concentrations.” However, there are also a small but vocal number of scientists in climate and climate-related fields that disagree with the consensus view.

Three is considerable opposition from some members of the political and business communities both to the conclusion that humans are causing climate change and to the need to take action to reduce human effects on climate. Chiefly, opposition arises because of claims that these actions would cause enormous expense and disruption to the current geopolitical and economic situation, with no obvious recognizable short-term benefits. This is a public and political debate. While the climate projections involved in the discussion are constrained by basic physical principles (though they depend on assumptions about emissions), political and economic effects of both global warming and mitigation are more difficult to quantify. As an example, in asking whether the costs of reducing fossil fuel dependency outweigh the costs of not taking action, one is confronted by the fact that it is difficult to anticipate social or technological changes that affect such costs.

Assertions by Proponents of Global Warming Theory

Supporters of the anthropogenic global warming hypothesis assert that:

· The fact that carbon dioxide absorbs and emits IR radiation has been known for over a century.

· Gas bubbles trapped in ice cores give us a detailed record of atmospheric chemistry and temperature back more than eight hundred thousand years, with the temperature record confirmed by other geologic evidence. This record shows a correlation between atmospheric carbon dioxide and temperature.

· The recent rise in carbon dioxide and other greenhouse gases is greater than any in hundreds of thousands of years and this is human-caused, as shown by the isotopic signature of CO2 from fossil fuels.

· The historical temperature record shows a rise of 0.4–0.8 °C over the last 100 years.

· The current warmth is unusual in the past 1000.

· Climate change attribution studies, using both models and observations, find that the warming of the last 50 years is likely caused by human activity; natural variability (including solar variation) alone cannot explain the recent change.

· Climate models can reproduce the observed trend only when greenhouse gas forcing is included.

· The IPCC reports correctly summarize the state of climate science.

· Humankind is performing a great geophysical experiment, and if it turns out badly—however that is defined—we cannot undo it. We cannot even abruptly turn it off. Too many of the things we are doing now have long-term ramifications for centuries to come.

· Climate models predict more warming, sea level rise, more frequent and severe storms, drought and heat waves, spread of tropical diseases, and other climactic effects in the future.

· The current warming trend will accelerate when melting ice exposes more dark sea and land that will reflect less sunlight; and when the tundra thaws and releases large quantities of trapped greenhouse gases.

· Atlantic hurricane trends have been recently linked to climate change.

· The Precautionary principle requires that action should be taken now to prevent or mitigate warming.

Proponents of the anthropogenic global warming hypothesis tend to support the IPCC position, and thus represent the scientific consensus (though with considerable differences over details, and especially over what action should be taken).

Assertions by Opponents of Global Warming Theory

Some of the assertions made in opposition to the hypothesis of anthropogenic global warming include:

· The field of climate science has been a “scientific backwater” because most of the bright students went into physics, math, or computer science. To improve the quality of climate science, the quality of the basic science underlying it must be improved.

· The relationship between historic temperatures and CO2 levels, based on ice-core samples, shows that carbon dioxide levels rise after global temperatures rise.

· IPCC draws firm conclusions unjustified by the science, especially given the acknowledged weakness of cloud physics in the climate models.

· The influential "Hockey Stick" study by Mann has been shown to contain errors.

· Correlation does not imply causation, so just because temperatures have risen overall since the beginning of the Industrial Revolution doesn’t necessarily mean that Industrialization has caused the change in temperature.

· The period since the beginning of the Industrial Revolution has produced “urban heat islands” that could be skewing temperature measurements that indicate the recent warming.

· Using "consensus" as evidence is an appeal to the majority argument rather than scientific discussion. Some have proposed that, because the issue has become so politicized, climatologists who disagree with the consensus may be afraid to speak out for fear of losing their positions or funding.

· Climate models will not be able to predict the future climate until they can predict solar and volcanic activity, changes in sea temperature, and changes to cosmic ray levels that make the low level clouds that cool the earth, and take into account other recently discovered feedback mechanisms.

· Estimates at CO2’s effectiveness as a greenhouse gas vary, but are generally around 10-100 times lower than water weight for weight, leaving a “net” greenhouse effect of man-made CO2 emissions at less than 1%.

· Climate science cannot make definitive predictions yet, since computer models used to make these predictions are still evolving and do not yet take into account recently discovered feedback mechanisms.

· Global temperatures are directly related to such factors as sunspot activity (an 11-year cycle).

· Global warming is largely a result of reduced low-altitude cloud cover from reduced Galactic cosmic rays (GCRs). It is similar in concept to the Wilson cloud chamber but on a global scale, where earth's atmosphere acts as the cloud chamber.

· The concern about global warming is analogous to the concern about global cooling in the 1970s. The concern about global cooling was unnecessarily alarmist. Therefore, the concern about global warming is likely to be equally alarmist.

· Many opponents also point to the Medieval warm period, which lasted from the 10th to the 14th Century, and which indicated an above-average temperature for at least Western Europe, and possibly the whole earth. This period was followed by the Little Ice Age, which lasted until the 19th Century, when the earth began to heat up again.

· Satellite temperature records show less warming than surface land and sea records.

· Climatic changes equal to or even more severe than those on Earth are also happening on other bodies within this solar system, including Mars, Jupiter, Pluto and Triton.

Reasons to take no action against Global Warming

Those who see global warming as an incorrect hypothesis are against preventative global warming measures for a number of reasons, as outlined below:

· There is a distinct correlation between GDP growth and greenhouse-gas emissions. If this correlation is assumed to be a case of causation, a cutback in emissions might lead to a decrease in the rate of GDP growth.

· Future scientific advances or engineering projects will remedy the problem before it becomes serious, and will do it for less money.

· A small amount of global warming would be benign or even beneficial, as increased carbon dioxide would benefit plant life, thus potentially becoming profitable for agriculture world-wide.

Do Cows Cause Global Warming?

According to a recent UN Study titled “Livestock’s Long Shadow,” the evidence points to farms, particularly ones that breed cattle and pigs, as the breeding grounds for global warming. According to the report, some 18% of CO2 emissions are related to livestock, 37% of Methane emissions are related to livestock, and 65% of Nitrous Oxide emissions are related to livestock!

� “Global Warming,” 14 Feb. 2007 < http://en.wikipedia.org/wiki/Global_warming>

� Ibid.

� Ibid.

� J.T. Houghton, et al., Climate Change 2001: A Scientific Basis (New York: Cambridge University Press, 2001) 101.

� “Global Warming,” 14 Feb. 2007 < http://en.wikipedia.org/wiki/Global_warming>

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� “Greenhouse Effect,” 14 Feb. 2007

� “Greenhouse Effect,” 14 Feb. 2007 < http://en.wikipedia.org/wiki/Greenhouse_effect>

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� J.T. Houghton, et al., Climate Change 2001: A Scientific Basis (New York: Cambridge University Press, 2001) 89-90.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� “Greenhouse Gas,” 14 Feb. 2007 < http://en.wikipedia.org/wiki/Greenhouse_gas>

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� “Kyoto Protocol,” 14 Feb. 2007

� Arianne Appel, “Global Warming Supercharged by Water Vapor,” National Geographic, 10 Nov. 2005, 14 Feb. 2007

� “Tunguska Event,” 14 Feb. 2007 < http://www.answers.com/topic/tunguska_event>

� “Tunguska Event,” 14 Feb. 2007 < http://www. en.wikipedia.org/wiki/Tunguska_event>

� Ibid.

� University of Leicester, “Greenhouse theory smashed by biggest stone,” 14 Mar. 2006, 14 Feb. 2007

� Ibid.

� Ibid.

� Ibid.

� University of Leicester, “Greenhouse theory smashed by biggest stone,” 14 Mar. 2006, 14 Feb. 2007

� Ibid.

� Ibid.

� “Tim Patterson,” 14 Feb. 2007 < http://www.sourcewatch.org/index.php?title=Tim_Patterson>

� Dr. Tim Patterson, “The Geologic Record and Climate Change,” TCS Daily, 01 Jan. 2005, 14 Feb. 2007 < http://www.tcsdaily.com/article.aspx?id=010405M>

� “Carbon Dioxide,” 14 Feb. 2007 < http://en.wikipedia.org/wiki/Carbon_dioxide>

� Ibid.

� “Ice Core,” 14 Feb. 2007 < http://en.wikipedia.org/wiki/Ice_core>

� Ibid.

� “Global Warming Potential,” 14 Feb. 2007 < http://en.wikipedia.org/wiki/Global_warming_potential>

� Ibid.

� Ibid.

� Monte Hieb, “Water Vapor Rules the Greenhouse System,” 10 Jan. 2003, 14 Feb. 2007

� Ibid.

� “Carbon Dioxide,” 14 Feb. 2007

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� “Carbon Cycle,” 14 Feb. 2007 < http://dictionary.reference.com/browse/carbon%20cycle>

� “Carbon Cycle,” 14 Feb. 2007

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� “Global Warming Controversy,” 14 Feb. 2007

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Ibid.

� Vincent Castel, et al., Livestock’s Long Shadow: Environmental Issues and Opinions (Rome: Food and Agricultural Organization of the United Nations, 2006) p. xxi.

PAGE

- 17 -