"Jesus cares about what we drive. Obeying Jesus in our transportation choices is one of the great Christian obligations and opportunities of the twenty-first century."(1) So proclaims the Evangelical Environmental Network on their "What Would Jesus Drive?" website. The issue seems absurd, but has a serious point. If the way we choose to drive harms other people, then servants of Christ must do what they can to minimize this harm. Doing otherwise would not entail loving one's neighbor as oneself. How can an individual's transportation choices harm others? The Evangelical Environmental Network explains, "Pollution that causes the threat of global warming violates the Great Commandments, the Golden Rule, and the Biblical call to care for 'the least of these,' and therefore denies Christ's Lordship."(2) If human activities cause global warming, then Christians have an obligation to avoid contributing to the problem.

The global warming theory states that human emissions of carbon dioxide cause the earth's atmosphere to trap excess heat, unnaturally warming the planet. Among other sources, automobiles, particularly less fuel efficient SUVs, emit large quantities of CO2. If man-made CO2 does in fact excessively warm the earth, then Christians should heed the Evangelical Environmental Network's call and watch what they drive, using only the most fuel efficient cars, and carpooling or using public transportation when possible. If, however, human CO2 emissions do not contribute to global warming, then the question "What Would Jesus Drive?" becomes an utter absurdity, since then gas guzzling would then harm no one, and carpooling does nothing to help the earth or one's fellow man. Consequently, Christians needs to know the facts about global warming in order to ensure that they live in accordance with Christ's commandments.

What are those facts? Anyone who reads the newspaper has no doubt learned that global warming represents a real and pressing danger to the health of the planet, and that it places millions of lives at risk. However, stepping away from the media spin, and looking at the underlying science reveals that scientists have uncovered little reliable evidence to support the popular hype that surrounds global warming. As a result, Christians have no reason to fear contributing to global warming, and may drive any vehicle with a clear conscience.

The Historical Record
The observed climate record of the past century represents one of the major flaws in the global warming theory. During the 20th century human emissions of CO2 grew rapidly, with most of that increase following the Second World War. According to the theory, this should have caused temperatures to rise over the past century, with most of that increase coming after World War II. Surface measurements reveal that the earth's temperature rose approximately 0.6°C during the 20th century, but this warming does not match the theoretical predictions. Most of the warming, 0.4°C, took place before the early 1940's, before the release of most man-made CO2 into the atmosphere. Then, until the late 1970's, while human emissions of CO2 rose rapidly, the earth actually cooled approximately 0.1°C, only to rise by another 0.3°C by the end of the century. Surface temperature records reveal almost no correlation between human CO2 emissions and temperature increases. The majority of the temperature increase took place before CO2 levels rose substantially, then the temperature decreased while CO2 emissions rapidly rose, only to reverse the trend and slightly increase by the end of the century.(3) Understandably, the history of actual human CO2 emissions and the temperature record does little to support the global warming theory.

However, climatologists base this temperature record on surface measurements from ground stations. Scientists know that these records suffer from a systematic bias that tends to increase the temperature they record, the urban "heat island" effect. Many ground-monitoring stations are located in areas that have grown into major cities. The high volume of human activity, and asphalt, which tends to trap heat, that a city contains raises the temperature of a city several degrees above that of the surrounding countryside. Consequently, temperature measurements taken in or near a city are noticeably higher than those taken in a rural area, and this bias shows up in the surface record.(4)

Fortunately, for the past quarter century scientists have an alternative climate record unaltered by the heat island effect, the satellite record. Since 1979, satellites orbiting the globe have recorded the earth's temperature using instruments with an accuracy of ±0.01°C. These more accurate satellite sensors show that, except for a one-year warming spike in 1998 caused by El Nino, the earth's average temperature did not rise between 1979 and 2000.(5) Temperature measurements from weather balloons corroborate these findings, which cast further doubt on the global warming theory. While atmospheric carbon dioxide has steadily risen, the most accurate measurements available show that the global temperature did not increase over the past two decades.

Still, the best records available suggest that global temperatures rose slightly over the past century. However, this is hardly unusual. Global temperatures naturally change, and have done so for thousands of years before the invention of the internal combustion engine. Over just the past millennia, global temperatures swung by several degrees. During the Middle Ages, in the medieval climate optimum, temperatures averaged one to two degrees higher than today's levels. During this time, Greenland was actually green, and supported vibrant Viking settlements. Following this warm period, and lasting into the mid 1800's, came the so-called "Little Ice Age," during which global temperatures dropped noticeably below today's levels. Since the 1850's, temperatures have risen as the earth left the mini-ice age.(6) These climate swings occurred as a result of natural processes, long before humans began emitting significant amounts of CO2. The fact that the earth has warmed by half a degree centigrade over the past century hardly represents an unusual historical occurrence or evidence that human activity has altered the climate.

Climate Models
The question naturally arises why so many politicians, journalists, and scientists believe in global warming when it has so little support from the historical record. The answer is that, despite the lack of empirical support, computer programs that model the global climate and make future predictions project that increased levels of atmospheric CO2 cause the global temperature to rise. It is on the basis of these climate models, run on some of the most powerful supercomputers in the world, that almost every prediction of global warming rests. The U.N.'s Inter-Governmental Panel on Climate Change (IPCC), the U.S. National Assessment of Global Warming, and virtually every other major global warming study rely on these computer forecasts to prove that human activity changes the climate.

However, these models are only computer simulations, not empirical facts. The quality of the programs, and the data fed into the programs, limits the accuracy of the model's predictions. If scientists don't fully understand all the parameters in the model, then the model will produce less than fully accurate projections. Unfortunately, all current climate models suffer from severe defects that limit their usefulness in projecting future climate change. These defects do not result from bad programming or dishonest intent on the part of scientists, but from fundamental limitations in current scientific knowledge that make more accurate models impossible.

Uncertain Parameters and Flux Adjustments
Current climate models do not accurately account for the effects of clouds and precipitation on the global climate.(7) Clouds and rainfall clearly affect the climate, but scientists don't know how model them accurately. Additionally, the models simply ignore changes in the level of the solar energy entering the atmosphere.(8) To put it mildly, the sun significantly affects the earth's climate. Nonetheless, the models assume that the level of solar energy striking the earth remains constant, despite the fact that scientists know that this is not the case. Climatologists must make this assumption, however, because they do not know how to predict future changes in solar radiation. Unsurprisingly, these limitations decrease the accuracy of the models.

Furthermore, researchers simply do not accurately know some climate parameters, and must use educated guesses in their models. Physics tells scientists that a doubling of the atmospheric CO2 increases the energy in the climate system by approximately four Watts per square meter (W/m2). At the same time, the uncertainty in measuring the amount of energy reflected into space or absorbed by the earth is on the order of 25 W/m2, and scientists cannot estimate energy flows from the equator to the North and South poles beyond a 25-30 W/m2 range.(9)

Scientists must use these parameters to model the climate, but they simply do not accurately know them. Models using "best guess" estimates of the parameters predict the unrealistic cooling of major oceans and other unlikely anomalies. To avoid absurd predictions, climatologists introduced "artificial flux adjustments," on the order of 50 to 100 W/m2, that stop the models from predicting the impossible. These flux adjustments lack any theoretical basis, but climatologists need them to make the models plausible.(10) In other words, the artificial adjustments that scientists make to their models to account for unknown or improperly measured or modeled variables are twelve to twenty five times the size of the effect of doubling the amount of carbon dioxide in the atmosphere. Consequently, no one has much reason to believe that the models can accurately forecast the future effect of increasing carbon dioxide on the earth's temperature.

Models Fail to Predict Current Temperatures
In fact, even the most advanced climate models cannot accurately model current weather patterns, much less those of a hundred years from now. No model currently in existence can produce forecasts remotely in line with the measured temperature of the troposphere, the lower 40,000 feet of the atmosphere.(11) Recent measurements over Antarctica indicate that major global climate models inaccurately forecast Antarctic stratospheric temperatures by 10 to 15 degrees centigrade, indicating that the models make fundamental errors in calculating how radiation disperses.(12) One of the two models that formed the core of the U.S. National Assessment of Global Warming "predicted" 300% more temperature change in America over the 20th century than actually occurred.(13) Due to systematic and unavoidable errors, even the most state of the art current climate models cannot accurately predict current weather patterns. The notion that they can predict the climate centuries from now is a stretch. Yet these models form the basis for the case that human activity unnaturally warms the planet.

No Scientific Consensus
Why, then, if the models face so many limitations, do newspapers, politicians, and advocacy groups proclaim that the scientific consensus is that the global warming theory is accurate? In fact, advocacy groups exaggerate these claims. Thousands of scientists do believe that man-made carbon dioxide emissions unnaturally warm the atmosphere, and thousands do not. Over 17,000 scientists signed the Oregon Institute of Science and Medicine's petition proclaiming that "there is no convincing scientific evidence that human release of … greenhouse gases is causing or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate."(14) Separately, more than 4,000 scientists, including 70 Nobel Prize winners, signed the Heidelberg Appeal, testifying that science provides no reason to limit the emission of carbon dioxide into the atmosphere.(15) While many scientists believe in the global warming theory, many do not, and scientists have not come to a consensus on the issue.

Bias in the IPCC
Many reporters and politicians claim that the scientific consensus supports global warming because of the United Nation's Inter-governmental Panel on Climate Change, the IPCC. While earlier IPCC reports equivocated, in 2001 the IPCC concluded that human CO2 emissions do warm the earth. However, the IPCC does not represent an impartial cross-section of scientists. The UN resolution that created the IPCC defined its mission as being "…to initiate action leading as soon as possible to recommendations with respect to the identification and possible strengthening of relevant existing international legal instruments having a bearing on climate …"(16) Thus, if the IPCC announced that it had discovered that human activity does not change the climate, and that no further international action was needed, it would violate the very resolution that created it.

Additionally, the governments of the IPCC member nations selected the conferees; they did not serve on the IPCC purely on the basis of their scientific credentials. Furthermore, only a third of the IPCC scientists actually had training as climatologists.(17) It should not come as an overwhelming surprise that a panel of political appointees, only some of whom had proper scientific credentials, came to exactly the conclusions that the UN declared that it wanted them to arrive at.

Flaws with the USNA
The National Academy of Sciences U.S. National Assessment of global warming (USNA) has exerted just as much influence as the IPCC in influencing American public policy. The USNA claims that global warming will wreak environmental and economic havoc on the United States throughout the 21st century, and forms the scientific basis for legislation placed before Congress by, among other legislators, Senate minority leader Thomas Daschle.(18) This politicized, agenda driven report, however, has virtually no scientific justification and does nothing to support the global warming hypothesis. Indeed, the report demonstrates the extent to which global warming proponents will stretch science to make it conform to their beliefs, regardless of the facts.

Former Vice-President and known global warming alarmist Al Gore initiated the USNA in 1997, and despite serious flaws, the government published the USNA ten days before the 2000 election, conveniently just days before Americans decided whether or not to elect Gore to the Presidency.(19) The fourteen person National Assessment "synthesis team" (NAST) selected to conduct the assessment included no global warming skeptics, only two climatologists, and only one member with a doctorate.(20)

The team then selected two climate models to form the basis of the report. Of the many major climate models available, the NAST chose the British "Hadley Model" and the Canadian model to predict the effects of global warming. Both models are statistical outliers, respectively predicting that global warming will cause greater increases in precipitation and temperature than any other model available.(21) If the NAST was looking to predict a worst-case scenario, it could not have selected better models. However, they were not the most reliable models available. In fact, when it comes to predicting the effects of global warming, they directly contradict each other, predicting drought and flooding in opposite areas of America. Even the Hadley center states that its models cannot accurately predict changes in local climate conditions, only in areas of 1000 kilometers or more.(22) Nonetheless, the NAST selected the Hadley and Canadian models, and used them to predict the effects of global warming.

The Canadian and Hadley regional predictions directly contradict each other

When the USNA report underwent peer review, the reviewers discovered a significant problem. In the words of reviewer Patrick Michaels, "The two climate models that are the core of the USNA perform no better than a table of random numbers when it comes to estimating U.S. temperatures during the period of greenhouse effect changes."(23) Even the United Nations agreed that the models were virtually useless. For all the effort that went in to the USNA, random guessing does a better job of predicting the climate than either of the models used by the NAST. The NAST commissioned its own study to analyze the models, and concluded that the reviewers were right; they also agreed that the models could not predict temperature change over the United States. Despite this, the team published the USNA anyway, less than two weeks before the election, predicting that global warming would inflict dramatic economic and ecological harm on America.(24)

The USNA received a great deal of media attention following its release, convincing many people that global warming presented a clear and present danger to America, but at best it represents a political document designed to elect Al Gore. At worst, it represented deliberate scientific dishonesty in the service of a political agenda.

Data Errors in the Hockey Stick Graph
Recently, auditors have revealed an even more disturbing case of scientific fraud in a report that promoted global warming. In 1998 Professor Michael Mann of the University of Virginia published a report analyzing the climate over the past six centuries. Since scientists do not have direct temperature records for all but the last century, Mann relied on 10 different proxy records, tree rings and ice core samples from around the globe, to discern the temperature of the earth before reliable temperature records began. On the basis of this study, Mann produced the famous "hockey stick" graph, which showed that the global climate had been relatively stable until 20th century, when temperatures rose dramatically. Based on this work, Mann claimed that the 20th century was warmer than any in the past 600 years.

It would be hard to overstate the influence of the Mann report and the "hockey stick" graph in the global warming debate. It seemed to deny the existence of both the medieval climate optimum and the Little Ice Age. It was one of the main reasons that the 2001 IPCC report unequivocally stated that humans were causing global warming, while earlier reports could not come to this conclusion. It formed the basis of Environment Canada's support for the costly anti-global warming Kyoto treaty, which the Canadian government has since signed.(25) The USNA also utilized the "hockey stick" graph in predicting dire consequences from global warming.(26) Mann's report seemed to provide supporters of the global warming theory with the empirical evidence that they had been lacking.

In 2003, Stephen McIntyre, a businessman with a strong statistical and mathematical background, and Professor Ross McKitrick of the University of Guelph conducted an independent audit of Mann's report. Analyzing the data used to generate the report, they determined that

The data set of proxies of past climate used in Mann … for the estimation of temperatures from 1400 to 1980 contains collation errors, unjustifiable truncation or extrapolation of source data, obsolete data, geographical location errors, incorrect calculation of principal components and other quality control defects. ... The major finding is that the values in the early 15th century exceed any values in the 20th century. The particular "hockey stick" … is primarily an artefact of poor data handling, obsolete data and incorrect calculation of principal components.(27)

Mann was only able to derive the "hockey stick" because of systematic errors in his data and his calculations. McIntyre and McKitrick corrected the data errors in Mann's work and produced the temperature graph Mann's research should have lead him to. This graph demonstrated that the 20th century was not unusual, that in fact the 15th century, with virtually no artificial emissions of carbon dioxide, was substantially warmer than the 20th century.

Mann's original "hockey stick" graph, and the corrected version. Note the high 15th century temperatures.

The Mann report, one of the most influential papers supporting the global warming theory, only achieved its breakthrough result through the use of poor data and erroneous calculations. Correcting those errors demonstrates that the empirical record does not support the global warming theory; it rests almost entirely on models of highly questionable accuracy.

The global warming theory has little to no empirical support, relies on highly inaccurate computer models that cannot forecast current, much less future, climate change, and is not supported by a broad scientific consensus. Key studies that support the global warming theory, the IPCC, the USNA, and Mann's 1998 report, all suffer from errors and biases. While these facts do not conclusively prove that global warming is not occurring - it is impossible to prove a negative - they certainly suggest that it is not. Consequently, Christians should not worry that their transportation choices might harm other people. Christians can choose to drive how they wish without fearing that their actions contribute to Global Warming and thus, in the words of the Evangelical Environmental Network, "deny Christ's Lordship." This does not mean that Christians do not need to consider God's desires in what they choose to drive. God clearly tells his servants not to glorify or take pride in material wealth, but to serve him first and store up treasures in heaven, and some luxury vehicles clearly express materialistic desires. It simply means that Christians have no reason to also consider the effects their car might have on the climate when purchasing a new vehicle. What Would Jesus Drive? Whatever he chose, the exaggerated hype surrounding the global warming theory would not concern him.

Footnotes

(1) http://www.whatwouldjesusdrive.org/resources/paper/
(2) http://www.whatwouldjesusdrive.org/resources/paper/moral.php
(3) Jack M. Hollander, professor emeritus of energy and resources at the University of California, Berkeley. "Rushing to Judgment," the Wilson Quarterly. Spring 2003. http://wwics.si.edu/index.cfm?fuseaction=wq.essay&essay_id=33083.
(4)Ibid.
(5)"The Satanic Gasses," ©2000, pg. 80, by Patrick Michaels, Ph.D., Research Professor of Environmental Sciences, the University of Virginia, former President of the American Association of State Climatologists, Contributing author and reviewer of the IPCC, and Robert Balling, Jr., Professor of Geography and Director of the Office of Climatology, Arizona State University.
(6)James Schlesinger, former Secretary of Energy, Environment News, August 1st, 2003. http://www.heartland.org/Article.cfm?artId=12591
(7)Willie Soon, physicist at the Solar and Stellar Physics Division of the Harvard-Smithsonian Center for Astrophysics, "Calculating the Impacts of Increased CO2: The Issue of Model Variation," First Eurocongress on The Solar Cycle and Terrestial Climate, Tenerife, Spain, September 25-30, 2000
(8)Joseph L. Bast, president and CEO of The Heartland Institute, a nonprofit research organization based in Chicago, Illinois. "The Questionable Science Behind the Global Warming Scare," Heartland Policy Study No. 88, Oct. 1, 1998. http://www.heartland.org/Article.cfm?artId=9442#part3
(9)Jay Lehr, science director for The Heartland Institute. "A Climate Change Primer: Computer Models and the Need for More Research." Environment News. July 1, 2003. http://www.heartland.org/Article.cfm?artId=12406.
(10)Soon et al, previously cited, 2003.
(11)Michaels and Balling, pg. 64.
(12)"Data Crashes Model-Topia," World Climate Report, Oct. 7th, 2002. http://www.co2andclimate.org/climate/previous_issues/vol8/v8n03/hot.htm
(13)Patrick Michaels, "Junk Science Hits the Washington Fan," Feb. 25, 2002. Online at http://www.cato.org/dailys/02-25-02.html
(14)Joseph Bast, previously cited, 1998.
(15)Sen. James Inhofe, Chairman, Senate Environment and Public Works Committee. Senate Floor Statement, July 28th, 2003.
(16)Michael and Balling, page 15.
(17)Ibid, pages 15-17.
(18)Patrick J. Michaels, "Flips, Flops, and Facts about Global Warming," June 10th, 2002. http://www.cato.org/dailys/06-10-02.html
(19)Ibid.
(20)Ibid.
(21)John L. Daly, Greening Earth Society Science Advisor, "The National Assessment Overview: Politics Disguised as Science," The Greening Earth Society, 2000. http://www.greeningearthsociety.org/Articles/2000/national.htm
(22)Myron Ebel, director of global warming and international environmental policy at the Competitive Enterprise Institute. "The National Assessment of Climate Change," Intellectual Ammunition, Sept./Oct. 2000. http://www.heartland.org/Article.cfm?artId=144
(23)Patrick J. Michaels, "Flips, Flops, and Facts about Global Warming," June 10th, 2002. http://www.cato.org/dailys/06-10-02.html
(24)Patrick Michaels, "Junk Science Hits the Washington Fan," Feb. 25, 2002. Online at http://www.cato.org/dailys/02-25-02.html
(25)Stephen McIntyre and Ross McKitrick, companion website to "Corrections to the Mann et. al. (1998) Proxy Data Base and Northern Hemispheric Average Temperature Series" which appeared in Energy & Environment, 10/28/03. http://www.uoguelph.ca/~rmckitri/research/trc.html
(26)John L. Daly, Greening Earth Society Science Advisor, "The National Assessment Overview: Politics Disguised as Science," The Greening Earth Society, 2000.
(27)Stephen McIntyre and Ross McKitrick, "Corrections to the Mann et. al. (1998) Proxy Data Base and Northern Hemispheric Average Temperature Series" Energy & Environment, 10/28/03. Available online in .pdf format at http://www.multi-science.co.uk/ee_openaccess.htm.