Science

Something Funny with Peer Review

As reported in our last issue, Thomas Wigley with the National Center for Atmospheric Research published a paper in Science claiming to have detected the human influence on global warming. Atmospheric scientist Fred Singer with the Science and Environmental Policy Project challenged the findings of the paper. In a response to Singer, Wigley included the following comments of the reviewers to his paper:

Referee #1: “Overall evaluation: Excellent and excitingpresents an insightful and deceptively simple analysis”

Referee #2: “Overall evaluation: excellent and excitingan exciting paper using an underutilized techniquedeserves rapid publication”

Referee #3: “This is an excellent and exciting paperhas some very interesting and important resultsa novel, yet simple approach”

Wigley commented, “I hope you will note the uniformity of the referees opinions.”

To which Singer said, “We certainly did. In fact, we are still trying to calculate the statistical probability that three reviewers, wholly unknown to each other and examining the paper independently–as they should–would each come up with the rather unusual phrase excellent and exciting” (www.sepp.org).

Scientists Argue about 1998 Weather

With the end of 1998, there has been a lot of ink spilled in the press about the odd and sometimes devastating weather that occurred over the last year. A few scientists want to blame global warming, others think it is just more of the same natural variation weve always experienced. “Of course, we have natural variability, but that doesnt account for what went on,” says Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research in Boulder, Colorado. “We dont have definitive answers, but there is reason to believe this is part of the signals of global warming we may be seeing.”

Jerry Mahlman, director of NOAAs Geophysical Fluid Dynamics Laboratory, disagrees. “Theres no bad guy out there,” Mahlman insists. “Basically, were getting jerked around by the same stuff thats been jerking us around for a long time.” Mahlman is referring to El Nio and La Nia that have a powerful effect on the earths weather patterns.

One thing that atmospheric scientists have learned is that El Nio/La Nia oscillations affect the path of the jet stream that moves weather systems around the globe. El Nio causes the jet stream to flow steadily across North America, suppressing hurricanes and tornadoes. La Nia pushes the jet stream north which “sets off a loopy pattern that streams in over the Northwest, curves down into the countrys mid-section and back up toward the East Coast” bringing heavy winter storms, spring tornadoes and more hurricanes. “All hell breaks loose,” according to Jim OBrien, director of the Center for Ocean-Atmospheric Prediction Studies at Florida State University.

Theres another reason why 1998s weather has seemed so strange, according to Mahlman. “A lot of topsy-turviness is an impression born of the fact that weather in the news has gotten a lot sexier than it used to be,” Mahlman says. “Everybodys interested in it. You hear more about weather far from where you live than you used to . . . . Everybody has a heightened sense of weather as something that can get you.”

Scientists like Trenberth argue that global warming will lead to a nightmare scenario of weather-related global catastrophes. Others think it is “hysterical nonsense.” Theres little evidence to support such scenarios, and even if it does happen, they argue that a certain amount of global warming would be a good thing. “We have this gigantic heat engine made up of land, water, air, ice that makes it so wonderful for us to live here,” says OBrien. “[Global warming] means youve just thrown another log on the fire” (Palm Beach Post, December 31, 1998).

Record Cold Temperatures in the Midwest

Most of the environmental reporters around the country are fond of pointing out record high temperatures that occur around the country whenever they discuss global warming. When temperatures are colder than ordinary theres a deafening silence. For example, Joby Warrick of the Washington Post (December 8, 1998) mentioned the unseasonable warm temperatures experienced in the eastern United States at the time in an article about global warming. He failed to mention, however, that at the same time the western United States was experiencing record cold temperatures.

Currently much of the nation is experiencing abnormally frigid conditions. According to an Associated Press article, “winter showed no mercy across much of the nation yesterday, bringing a record cold reading of 36 degrees below zero to Illinois, more than a foot of new snow to heavily blanketed upstate New York and rare frigid conditions all the way south to the Gulf Coast.”

The death toll from the cold weather stands at 91, most occurring from traffic fatalities from slick roads. In Mobile, Alabama the temperature dropped to 18 degrees, breaking a 75 year old record (Washington Post, January 6, 1999). So far, Al Gore has not attempted to link the cold weather to global warming.

Etc.

Canadas Environment Minister Christine Stewart made some startling remarks at a meeting with the editorial board of the Calgary Herald. “No matter if the science is all phony,” she said, “there are still collateral environmental benefits,” to reducing greenhouse gas emissions. She also revealed the true agenda of the global warming activists. “Climate change [provides] the greatest chance to bring about justice and equality in the world.” Such is the marriage between old welfare statism and the new environmentalism (Financial Post (Canada), December 26, 1998).

Announcements

• The Competitive Enterprise Institute has released a monograph, titled Doomsday Dj vu: Ozone Depletions Lessons for Global Warming. Author Ben Lieberman argues that rather than serving as a successful model for the Kyoto Protocol, the Montreal Protocol should serve as a cautionary tale. Its mistakes would be greatly amplified if repeated under the Kyoto Protocol. The study can be obtained from CEIs website at www.cei.org or by contacting CEI at (202) 331-1010.

• The transcripts from the Cooler Heads science briefings for congressional staff and media and CEIs Costs of Kyoto lectures are becoming available on CEIs website at www.cei.org. Transcripts currently available include, Climate Change: Insights from Oceanography, by Dr. Roger Pocklington; Global Warming: Evidence from the Satellite Record, by Dr. John R. Christy and Dr. Roy Spencer; Global Warming and Vector-Borne Disease: Is Warmer Sicker? by Dr. Paul Reiter; Kyoto & Our Collective Economic Future: Economic & Energy Underpinnings, by Mark P. Mills; and most recently available, Emissions Credits: The Supply and Demand Gap, by Robert Reinstein.

No Smoking Gun Yet

Climate modelers have been laboring diligently to find the statistical smoking gun that would show once and for all that humans are responsible for global warming. So far they have been unsuccessful even though billions of tax dollars have been dedicated to the task. The search continues, however.

In a recent issue of Science (November 27, 1998) Thomas Wigley with the National Center for Atmospheric Research, and colleagues claim to have found the human finger-print in the global temperature data. They arrived at this conclusion by running two model simulations without natural or anthropogenic external forcing in order to mimic natural variation. They then added anthropogenic forcings such as carbon dioxide and aerosols and a natural forcing, solar radiation. They wanted to determine if one type of forcing or the other or both combined best explain the difference between the control-run model and the observed temperature data. They also took into account lags that may occur between the actual forcing, a change in solar radiation, for example, and the climate response.

Wigley, et al, found the “best-fit” by adjusting the climate sensitivity of the different forcing effects to minimize the “modeled and observed global-mean temperatures.” They then subtracted “best-fit and specific-sensitivity results” from the observed data. The result showed that a combination of anthropogenic forcing and changes in solar radiation most closely matches the climate model control-run.

The researchers made the critical assumption “that the . . . control-run data provide a reasonable representation of the unforced behavior of the real climate system.” If this is true, say the authors, “then a marked difference between the observations and the control-run results would provide evidence of external forcing effects in the observed temperature record.” They do indeed find a large difference. There are three possible explanations for the differences, however: “gross errors in observations, lack of realism of model control runs, or the existence of external forcing effects in the observations.”

The authors discount the first two possibilities. The quality of the data is not in doubt, they claim. However, Fred Singer an atmospheric scientist with the Science and Environmental Policy Project, argues that the data prior to 1945 is of very poor quality, especially in the Southern Hemisphere (The Electricity Daily, December 21, 1998). Second they argue that “there is no evidence to suggest that they [climate models] underestimate the magnitude of internal variability on time scales of 20 to 100 years by the large amount required to explain the . . . differences.” If this is true, however, climatologists should be able to forecast the annual temperature for the next 20 to 100 years. Few climatologists would make that claim.

The Dust Bowl Cometh

The dust bowl of the 1930s was not a one-time occurrence according to researchers with the National Oceanic and Atmospheric Administration. Using tree rings, submerged tree trunks, archaeological finds, lake sediments, and sand dunes, they were able to construct a history of drought events in the Midwest. According to Connie Woodhouse, one of the researchers at the University of Colorado, “Theres this 20-year periodicity of drought, were not sure what that is due to, but it seems to be fairly regular . . . . So if thats true, we should be expecting another drought, maybe a big drought in the next two years.”

The researchers also found that in the last 700 years there have been two “mega-droughts” that lasted for two to four decades each. A sixteenth century mega-drought lasted 20 to thirty years and may have stretched from the West to the East Coast. Even in the face of overwhelming evidence that such droughts occur naturally, some scientists still cant resist linking manmade global warming. According to Kevin Trenberth, head of climate analysis for the National Center for Atmospheric Research, “With global warming there is an expectation that if conditions do set up right with droughts, that the droughts could be more severe and last longer than they have in natural conditions in the past” (Knight Ridder Newspapers, December 16, 1998).

Important Ocean Data Gathered Amid Controversy

One of the most important experiments to measure ocean temperatures has been very successful regardless of attempts by the greens to thwart research. The researchers used “loudspeakers submerged off the coast of Hawaii and California to generate low-frequency booming sounds.” Listening devices were used to measure sound speed that indicates the ocean temperature since sound moves faster through warmer water. The method has allowed scientists to accumulate detailed information about ocean temperature. Carl Wunsch, a professor of physical oceanography at M.I.T. claims that when merged with satellite data and other instruments the new data is “far better than anything weve ever had before.” Wunsch says that “I can tell you whats going on in the Pacific Ocean, day by day, in three dimensions.”

The data also suggests that computer climate models may be excessively pessimistic in their predictions regarding such things as sea level rise. The researchers compared their findings with one such model and found that reality is far more complex than modeled. Factors other than thermal expansion, such as tides and changes in salinity also affect the elevation of the ocean. Walter Munk, a professor emeritus of geophysics at the Scripps Institution of Oceanography at the University of California at San Diego and a project leader, says that “My own feeling is that the models have not been adequately tested, and it is dangerous to make major economic decisions on the basis of model predictions.”

Green activist groups such as Greenpeace, the Environmental Defense Fund, and the Natural Resources Defense Council tried to stop the project, claiming that the sounds could damage marine life, even though marine biologists had determined that it was harmless. The project spent large amounts of money and time trying to quell environmental concerns, severely hampering the projects effectiveness. The project is now on hold and may not be revived, even though it could provide valuable information on the oceans and their effect on climate (The Chronicle of Higher Education, December 11, 1998).

Atlantic Storms May Suppress Global Warming

According to oceanographers, storms in the Atlantic ocean, and in particular the North Atlantic, act like a “giant pump” that keeps carbon in circulation. Hurricanes, for example, “churn up water to a depth of as much as 500 metres. . . transferring carbon dioxide from the surface to deeper levels of the ocean.” This allows the surface waters to absorb more carbon dioxide. Oceanographers believe that the North Atlantic alone has absorbed as much as one-quarter of manmade carbon dioxide emissions since the beginning of the industrial revolution. The findings were presented at a conference at the University of Bremen in Germany (Deutsche Presse-Agentur, December 14, 1998).

Announcements

• The Competitive Enterprise Institute has released a monograph, titled Doomsday Dj vu: Ozone Depletions Lessons for Global Warming. Author Ben Lieberman argues that rather than serving as a successful model for the Kyoto Protocol, the Montreal Protocol should serve as a cautionary tale. Its mistakes would be greatly amplified if repeated under the Kyoto Protocol. The study can be obtained from CEIs website at www.cei.org or by contacting CEI at (202) 331-1010.
• The transcripts from the Cooler Heads science briefings for congressional staff and media and CEIs Costs of Kyoto lectures are becoming available on CEIs website at www.cei.org. Transcripts currently available include, Climate Change: Insights from Oceanography, by Dr. Roger Pocklington; Global Warming: Evidence from the Satellite Record, by Dr. John R. Christy and Dr. Roy Spencer; Global Warming and Vector-Borne Disease: Is Warmer Sicker? by Dr. Paul Reiter; Kyoto & Our Collective Economic Future: Economic & Energy Underpinnings, by Mark P. Mills; and most recently available, Emissions Credits: The Supply and Demand Gap, by Robert Reinstein.

Hotter Now than Ever?

Paleoclimatologists have used proxy data (tree rings, ice cores, and so on) to reconstruct the Earths climate in the distant past. Many remarkable discoveries have been made, including the fact that climate has changed dramatically and rapidly in the past due entirely to natural causes. Others are claiming, however, that this evidence shows that the current warm period is human-induced.

Jonathan Overpeck, head of the paleoclimatology program for the National Oceanic and Atmospheric Administration, told an audience at a meeting of the American Geophysical Union in San Fransisco, that the earth is warmer now than it has been in the last 1,200 years. “There is no period that we can recognize in the last 1,200 years that was as warm on a global basis,” said Overpack. “That makes what were now seeing more unusual, and more difficult to explain without turning to a greenhouse gas mechanism.”

“Not only,” said Overpack, “has the 20^th century produced the hottest years on record but the magnitude of change appears to be without parallel since at least 800 A.D.” Overpack also addressed the issue of the dramatic warming of the Middle Ages, known as the Medieval Warm Period, which has been used as an historic example of dramatic natural climate change. Overpack claims that it never happened. He argues that “the thaw appears to have been limited to northern latitudes in Europe and North America, while other parts of the globe saw little change in temperature” (Washington Post, December 8, 1998).

Overpacks argument is specious, however. He claims that the temperature changes of this century are global, but this is untrue. Patrick Michaels, a climatologist at the University of Virginia, has pointed out that the small amount of surface warming over the last century has been largely confined to the northern latitudes of America and Siberia. The rest of the globe has remained mostly unchanged, similar to the Medieval Warm Period. This, of course, raises global average temperatures but so did it in the Middle Ages.

How Widespread are El Nios Effects?

This last year has seen the rise of El Nios fame. Many of 1998s notable weather events were generally linked to El Nio in the press. This may have given the public the impression that El Nio has more influence on the worlds climate system than is warranted. The September issue of the International Journal of Climatology addresses the issue of El Nio/La Nia impacts.

The study looked at El Nios impact (thought to be significant) on the South Pacific by studying upper atmospheric winds for three major La Nias and four El Nios since 1975. They found, “a considerable deal of inter-cold and warm event variability in the propagation of height and temperature anomaly patterns [such that] clear and unequivocal propagation signals common to all cold and warm events are not revealed. This is because the anomaly movement is rarely consistent from one warm (cold) event to another, especially in the subtropical to subpolar latitudinal range.”

Commenting on the study, the World Climate Report explains, “outside of the tropics, the impact from every El Nio or La Nia event differs. There is no compelling evidence that El Nios are becoming more common . . . .[or] are linked to global warming. In short , El Nios are like all other climate events unpredictable” (www.nhes.com).

El Nio and Temperature Change

The link between global warming and El Nio has not yet been made, but this has not stopped global warming activists from connecting the two phenomena. John Daly has taken a look at the satellite temperature data and the southern oscillation index (SOI), “an index number derived by comparing air pressure at sea level between Darwin and Tahiti. During an El Nio episode, the index becomes a negative number, and is characterized by warming of the central and eastern Pacific Ocean . . . . During a La Nia episode, the reverse happens and a cooling takes place.” By comparing the two sets of data it is easy to see that there is a cause and effect relationship between temperature and the SOI, but it is the El Nio/La Nia cycle that effects temperature and not the other way around.

The data show that “global temperature lags the SOI by between 6 and 9 months,” says Daly. “It is clear that the Southern Oscillation is the causative agent. An effect can only follow a cause, it cannot precede it, and so there is no dispute here about what the chain of cause and effect must be.

Daly argues that, “based on the the assumption that the Southern Oscillation is the primary driver of year-to-year global temperature, with a 6 to 9 month lag time, we can now predict that since the SOI has now gone sharply into La Nia mode in the last 6 months, global temperature will follow (with the predicted time lag) and fall to below the zero line (the long term average of temperature) in the next few months. The latest monthly value for temperature was +0.33C in October 1998, after reaching a peak of +0.72C in April. Since the SOI moved into La Nia mode in June, we can expect global temperature to fall below the zero line by March 1999.”

Commenting on the claim that manmade carbon emissions is the cause of El Nio Day says, “The Greenhouse industry readily blames greenhouse gases, but the idea that a few parts per million of CO₂ can cause the overturning of trillions of megatonnes of sea water is fanciful to say the least, a reasoning based more on ideology than on science. Those who point to greenhouse gases as the cause of El Nio fail to describe exactly what mechanism they imagine the gases to be performing to achieve such a feat” (www.vision.net.au/~daly/soi-temp.htm).

Hansen Falls Back to Weaker Position

In 1988 James Hansen, a climate modeler with NASAs Goddard Institute for Space Studies, put global warming on the political map and in the press by exclaiming before Al Gore in a Senate hearing that he was 95 percent sure that manmade global warming was upon us. However in the most recent issue of the Proceedings of the National Academy of Sciences (October 1998) he makes a startling statement. In the first sentence of the abstract he states, “The forcings that drive long-term climate change are not known with an accuracy sufficient to define future climate change.”

The study discusses several climate forcings, both positive and negative, that effect the earths climate. The purpose of the study, says Hansen, et al, is to “provide a perspective on current understanding of global climate forcings, in effect an update of the Intergovernmental Panel on Climate Change.”

The reason it is so difficult to predict future climate change, says Hansen, is that “anthropogenic greenhouse gases (GHGs), which are well measured, cause a strong positive (warming) forcing. But other, poorly measured, anthropogenic forcings, especially changes of atmospheric aerosols, clouds, and land-use patterns, cause a negative forcing that tends to offset greenhouse warming. One consequence of this partial balance is that the natural forcing due to solar irradiance changes may play a larger role in long-term climate change than inferred from GHGs alone.”

His discussion of solar irradiance is important because he challenges the notion that “climate forcing due to solar variability is negligible because it is much smaller than GHG forcing.” According to Hansen, “a more relevant comparison is with the net forcing by all other known mechanisms.” This net forcing, says Hansen, is probably only about 1 W/m² (watt per square meter). “Thus,” says Hansen, “a solar forcing of even 0.4 W/m² could have played a substantial role in climate change during the Industrial era.”

The Greening Earth

The Greening Earth Society has just released a video titled, The Greening of Planet Earth Continues, that reviews the global warming controversy. It begins by pointing out that we have records of the suns energy output, as measured by the sunspot cycle, for the last 400 years, since the time of Galileo. It turns out, says Sallie Baliunas, senior astrophysicist with the Harvard-Smithsonian Center for Astrophysics, that “the ups and downs of the suns magnetism match up very well with these changes in the climate of the earth. So we estimate that most of the changes of the last several hundred years . . . can be caused by these fluctuations in the suns energy output.”

The video also argues that the human race has flourished during warmer periods and stagnated during cooler periods. Two previous periods, known as “The Climatic Optimum” and the “Little Climatic Optimum” were warmer than it is now. “A slightly warmer world and an enriched carbon dioxide world will mean plant growth is more vigorous,” says Thomas Gale Moore, a Senior Fellow with the Hoover Institution, Stanford University. “The bottom of the food chain is plants. All animals eat plants or eat animals that eat plants, including us.”

The video also discusses the shortcomings of General Circulation Models. The different components of the climate system are very complex, according to Roy Spencer, a senior scientist with NASAs Marshall Space Flight Center. “They interact in non-linear ways which we really cant predict. One thing changes, which changes something else, which changes something else. Theres this cascade of processes.” The bottom line is that the models predictions have failed to conform to what has occurred.

The main point of the video is the central importance of carbon dioxide for life on earth. As pointed out by Sylvan Wittwer, professor emeritus of horticulture, Michigan State University, “Carbon dioxide is not a pollutant. Carbon dioxide is a nutrient a very important nutrient, perhaps the most important.” Increased levels of carbon dioxide in the atmosphere will be a boon to farmers and to plant life in general. Not only does it provide plants with the most important nutrient, it also increases water-use efficiency and nitrogen-use efficiency, both very important for plants.

One statement by Patrick Michaels, a climatologist with the University of Virginia, sums up the videos arguments: “The evidence that increasing carbon dioxide in the atmosphere is going to cause a disaster is somewhere between slim and none. However, the evidence that its doing a good thing by lengthening the growing season and making plants grow better is somewhere between large and overwhelming.” The video can be acquired by contacting the Greening Earth Society at (703) 907-6168 or info@greeningearthsociety.org.

Etc.

In an editorial about scientific literacy Vice President Al Gore decried what he perceives to be industrys exploitation of the publics scientific ignorance to oppose ratification of the Kyoto Protocol. “But industry opponents of the Kyoto Protocol are also attempting to undermine public support for the protocol by funding a massive public relations campaign attacking the findings of the worlds expert climate scientists,” says Gore. “This assault takes political advantage of the fact that too many Americans lack sufficient science literacy to tell the difference between sound science and sound bites.”

Gore goes on to say, “public understanding and support for reasonable climate change policies will be critical. But scientific literacy is necessary if we are to engage in an informed and rational debate. Unfortunately, scientific illiteracy means that too many Americans will be easy marks for anti-scientific public relation ploys.” Someone should remind Gore that over 17,000 scientifically literate persons signed the Oregon Petition that rejected the global warming hypothesis.

More on the Effects of CO₂ on Plant Life

It has been argued that the benefits to plant life of carbon dioxide may only be short term, that they are self-limiting. One of the hypotheses along these lines argues that dead plant tissue (litter) from plants grown in a carbon dioxide rich environment will decompose more slowly because there is less nitrogen in the plant tissue. Since the litter will have lower nitrogen content and decompose more slowly, “then decomposing organisms would have food of lower quality, and the transfer of organically bound nitrogen to the pools of mineral nitrogen available for plant growth could slow.” This leads to a “negative feedback on net plant productivity in the future.”

At a forum on Litter Quality and Decomposition under Elevated Atmospheric CO₂ at a meeting held in Capri, Italy, plant physiologists, ecologists and soil scientists concluded that this hypothesis is not valid. “Most experiments, carried out in various ecosystems such as forests, agro-ecosystems, grasslands and a salt marsh, have reported little change in litter chemistry and no significant difference in decomposition rates under different CO₂ concentrations.”

A possible positive feedback on plant productivity was also reported at the meeting. A slower initial decomposition may actually promote more complete long-term decomposition. High nitrogen content causes rapid initial decomposition and retards long-term decomposition. This can lead to “a more fertile habitat resulting from increased root litter in CO₂ enriched grasslands,” for instance (Nature, November 5, 1998).

Mammoth Icebergs Are Not Unusual

In October the press reported that an iceberg the size of Delaware had broken free of Antarctica. The event, it was argued is another “possible indicator of global warming” (The Washington Post, October 16, 1998). As is usually the case with most stories touting global warming, this was an entirely natural occurrence. Very large icebergs break away from Antarctical all the time. The following was reported on the Junk Science webpage (www.junkscience.com).

“For a little perspective, we go to page 748 of the 1996 edition of The American Navigator, the prestigious Naval text updated continuously since 1799 (sometimes referred to as “The Bowditch.”)

“The text reads In 1854 and 1855, several ships in the South Atlantic reported a crescent-shaped iceberg with one horn 40 miles long, the other 60 miles long, and with an embayment 40 miles wide between the tips. In 1927 a berg 100 miles long, 100 miles wide, and 130 feet high above the water was reported. The largest iceberg ever reported was sighted in 1956 by the USS Glacier, a U. S. Navy icebreaker, about 150 miles west of Scott Island. This berg was 60 miles wide and 208 miles long, more than twice the size of Connecticut. Icebergs ten miles or more in length have been seen on many occasions in the Antarctic.

“Notice that this last iceberg was more than 4 times bigger than that little ice cube noted in the Washington Post story. And by some miracle, the world did not come to an end after the discovery of this giant. So last week’s iceberg was not so extraordinary — except that it was perhaps the first linked to the dreaded global warming.”

North America Absorbing Carbon

One of the biggest mysteries in the global warming debate is the disappearance a large amounts of man-made greenhouse gases. Humans emit 7.1 petagrams of carbon dioxide each year. It is estimated that about half enters the atmosphere, 2 petagrams go into the oceans and 1.1 to 2.2 petagrams are absorbed by plants. What happens to the remainder is still unknown.

A new study in Science (October 16, 1998), however, argues that North America absorbs 1.7 petagrams of carbon per year, much more than previously thought. If true this means that not every gram of carbon released in the United States and Canada enters the atmosphere, but many are absorbed by the newly detected sink.

The researchers used data on carbon dioxide levels taken from 1988 to 1992 at 63 ocean-sampling stations. They plugged the data into two computer models, one which estimates ocean uptake and release of carbon dioxide, the other which estimates the how carbon dioxide is distributed by wind currents. What the researchers found is that carbon dioxide levels slightly decreased from west to east across North America even though levels were expected to increase as a result of fossil fuel emissions. This suggests a large North American sink.

The study is being criticized in some quarters, however. Inez Fung, a climate modeler with the University of California at Berkeley, argues that the models “could be off by just a little bit, and you get a very different conclusion.” Others point out that the study period includes the Mount Pinatubo eruption, a period where cooler and wetter conditions increased carbon uptake. Other studies trying to measure carbon uptake by sinks have come up with different results.

According to one of the team members, Jorge Sarmiento of Princeton University, part of the reason why other studies have failed to find such a large sink is that they “missed a lot of forest regrowth on abondoned farmland and formerly logged forests in the east fertilized by CO₂ or nitrogen pollution, and that they fail to account for carbon stored in soils and wetlands.”

Another study in the same issue of Science finds that South American tropical forests account for about 40 percent of the missing sink. While preliminary and contradictory, these studies suggest that much is still unknown about the carbon cycle. As stated by Heimann, “the most obvious conclusion” would be that “theres no need for the U.S. and Canada to curb emissions.”

Antarctic Ice Cap is Not Shrinking

The Intergovernmental Panel on Climate Change predicts that a warming planet will cause the worlds glaciers to melt and raise sea levels to potentially dangerous heights. A new study published in Science (October 16, 1998), however, shows that the Antarctic ice cap is not melting as a result of global warming. Measurements taken by remote sensing satellites show that on average the height of the ice cap is changing by less than 1 cm per year

There seems, however, to be an unspoken rule among warming proponents that good news must be reinterpreted as bad news. Instead of evidence against global warming, these findings suggest that the consequences of global warming may be worse than believed, according to Professor Duncan Wingham of the University College London, who led the research.

Since the sea level is currently rising by 1.8 cm per decade, one would expect the Antarctic ice cap to have shrunk by 5 cm to account for the observed sea level rise. This must mean that global warming is causing greater thermal expansion than expected. Global warming, concludes Wingham, will cause sea levels to rise by one meter over the next century, entirely due to thermal expansion (Financial Times (London), October 16, 1998).