Why Global Warming Is Hot Again

Dennis Avery’s “Global Warming . . . Boon for Mankind?” appeared in the 1998 spring issue of American Outlook and was reprinted in Reader’s Digest. Now, five years later, he writes about new research that reinforces his analysis and connects Earth’s temperature changes directly to the sun. This article is excerpted from his forthcoming book, due out in 2004.

The Hysteria:

“. . . [S]cientists predicted that the earth will shortly be warmer than it has been in millions of years. A climatological nightmare is upon us. It is almost certainly the most dangerous thing that has ever happened in our history.”      —Art Bell and Whitley Strieber, The Coming Global Superstorm, Pocket Books, 2000.

“No matter if the science [of global warming] is all phony . . . climate change [provides] the greatest opportunity to bring about justice and equality in the world.” —Christine Stewart, former Canadian Minister of the Environment, as quoted by the Calgary Herald, 1998.

“No matter if the science [of global warming] is all phony . . . climate change [provides] the greatest opportunity to bring about justice and equality in the world.” —Christine Stewart, former Canadian Minister of the Environment, as quoted by the Calgary Herald, 1998.

“From sweltering heat to rising sea levels, global warming’s effects have already begun. . . . We know where most heat-trapping gases come from: power plants and vehicles. And we know how to limit their          emissions.”—Natural Resources Defense Council (nrdc.org), May 27, 2003.

According to the greenhouse-warming theory and its billion-dollar computer models, the Earth is warming fiercely due to harmful emissions from human factories and automobiles. The United Nations Intergovernmental Panel on Climate Change (IPCC) claims that the Earth may warm more than 10 degrees Fahrenheit later this century unless greenhouse emissions are radically reduced.

      The Earth itself is telling us something much less dramatic: We’re in a mild, erratic natural warming cycle (driven by a cyclical uptick in the sun’s energy) that will gradually return us to the finest weather pattern in all recorded history—the Medieval Climate Optimum (circa 900–1300 AD). Winters will be milder, storms less powerful, and rainfall more abundant. The polar ice caps will not melt, and the sea level will continue to rise very slowly.

Reality Check:

“The study, appearing in the March 21, 2002 issue of the journal Science, analyzed ancient tree rings from fourteen sites on three continents in the northern hemisphere and concluded that temperatures in an era known as the Medieval Warm Period some 800 to 1,000 years ago closely matched the warming trend of the twentieth century.” —Associated Press report, March 22, 2002.

 Recently, scientists have used Earth’s own records to find that the planet has had nine moderate global warmings and nine somewhat harsher global coolings in the last 12,000 years—in a 1,500-year cycle that coincides exactly with a known cycle in the magnetic activity of the sun. These temperature cycles were independent of carbon-dioxide levels.

Because humans can do virtually nothing to alter the sun, we will have to adapt to this modest warming—perhaps 3 degrees Fahrenheit on average at its peak—just as animals and plants alike have been adapting to the Earth’s warming and cooling cycles for many thousands of years. That is much better news than the catastrophic predictions of the global-warming crusaders, of course, but they are not relieved. Instead, they are determined to prove the new findings wrong.

 Reality Check:

The middle-range forecast of the estimates of the UN Intergovernmental Panel on Climate Change, based on expected growth in fossil fuel use without any curbs, consists of a one degree Celsius increase over the next half century. A climate simulation including the effect of implementing the Kyoto Protocol

. . . calling for a world-wide five percent cut in carbon dioxide emissions from 1990 levels would reduce that increase to 0.94 degrees Celsius. —Dr. Sally Baliunas, Harvard-Smithsonian Center for Astrophysics, February 5, 2002.

Greenhouse Defects

No one disputes that modern society is emitting more greenhouse gases, especially carbon dioxide, into the atmosphere. During the last Great Ice Age, 15,000 years ago, the average concentration of carbon dioxide in the atmosphere was 190 parts per million (ppm). At the beginning of the Industrial Revolution, the carbon-dioxide concentration was about 275 ppm. In the past three hundred years, carbon dioxide has risen to about 350 ppm. This is not high by the standards of Earth’s history, however. Most of our plant and animal species evolved during a period when the carbon-dioxide concentration was several times greater.

The real question is: what does today’s additional carbon dioxide mean to global climate change?

Global-warming advocates draw a direct connection between higher concentrations of carbon dioxide and higher global temperatures. However, there is little real-world evidence to support this view. The advocates do not like to be reminded that virtually all of the warming in the Earth’s recent temperature record occurred before 1940—before the emission of much greenhouse gas from human activities.

Dr. John Christy, professor of Atmospheric Science at the University of Alabama at Huntsville, compiles the temperature readings from U.S. weather satellites. He recently testified before a U.S. House Committee:

The concentration of carbon dioxide is increasing in the atmosphere, due primarily to the combustion of fossil fuels. Fortunately . . . carbon dioxide is not a pollutant. In simple terms, carbon dioxide is the lifeblood of the planet.

Over the past twenty-four years, various calculations of surface temperature indeed show a rise of about 0.7 degrees Fahrenheit. This is roughly half the total rise observed since the nineteenth century. In the lower troposphere, however, various estimates, which include the satellite data Dr. Roy Spencer of UAH and I produce, show much less warming, about 0.3 degrees Fahrenheit . . .

Our UAH satellite data and the [high-altitude] balloon data corroborated each other with remarkable consistency, showing only a slow warming of the bulk of the atmosphere. This evidence indicates that the projected warming of the climate model had little consistency with the real world. This is important because the quantity examined here, lower tropospheric temperature, is not a minor aspect of the climate system. This represents most of the bulk mass of the atmosphere, and hence the climate system. The inability of climate models to achieve consistency on this scale is a serious shortcoming and suggests projections from such models be viewed with great skepticism.

. . . This evidence indicates that the projected warming of the climate model had little consistency with the real world. [Testimony to House Resources Committee, May 13, 2003.]

The Hysteria:

“Average global temperatures in 2002 could be the highest ever recorded, British weather experts said yesterday.” —Reuters News Service, August. 2, 2002. (Temperature records only go back to 1860—the end of the Little Ice Age.)

During the Medieval Climate Optimum, global temperatures were about 1 to 3 degrees Fahrenheit higher than our current temperatures (See Global Changes in the Perspective of the Past, edited by J.A. Eddy and H. Oeschger, Wiley and Sons, 1993). During the Little Ice Age, which lasted from about 1300 to 1850 AD, temperatures in Europe and Asia fell 2 to 4 degrees Fahrenheit below the present and may have dipped as much as 9 degrees Fahrenheit lower during the thirteenth century (See Climatic History and the Future, vol. 2, Princeton University Press, 1985, p. 463). We have less exact knowledge of temperatures during the Roman warming or in the mini-Ice Age that followed it. However, it is clear that the Earth’s climate has been cycling warmer and colder as far back into history as the records go.

The Medieval Climate Optimum was one of the most favorable periods in human history. Crops were abundant because winters were milder and growing seasons were longer. There was more rainfall because higher sea temperatures evaporated more moisture, which then descended again as rain or snow. Farmers moved farther up the mountain slopes—and farther north in Scandinavia, Russia, Manchuria, and Japan. The Vikings discovered Greenland, which really was green with grass; three thousand colonists pastured cattle on what is now frozen tundra.

What did not happen is equally interesting from our modern perspective: Rising sea levels did not inundate low-lying cities. Malaria mosquitoes did not infest Sweden. Virtually none of the scary scenarios currently being advanced to help convince us to quadruple our energy prices actually occurred during the medieval warming.

After 1300 AD, the world began to cool, and the Little Ice Age began to develop across the planet. Harsh weather problems emerged as a result: the Little Ice Age brought deeper cold, fiercer storms, severe droughts, more crop failures, and more famines. The Viking dairy colonists in western Greenland starved. The fishing colony in eastern Greenland lasted another one-hundred-and-fifty years before ice closed in on it, too (See The Little Ice Age; Basic Books, 2000, pp. 66-68).

The number of glaciers in Europe and North America peaked between the late 1600s and mid-1700s. Glaciers in the Southern Hemisphere peaked later, after 1800. The innovative historical climate research analyst, H. H. Lamb, notes that oxygen isotopes from German oak trees document a continuing decline in temperatures from 1350 to about 1800.

Was the Global Climate Global?

The medieval and Roman warmings, and their intervening cold periods, present a huge problem for believers in man-made global warming, and they know it. One of their responses has been to dig up new data that seems to contradict the evidence of natural cycles in the global climate.

For example, in 1995, the IPCC published its five-year report, Global Climate Change. In it, the panel published a graph of global climate change clearly showing the medieval warm period with temperatures higher than today’s, and sharply cooler temperatures during the Little Ice Age.

Six years later, however, the IPCC’s third assessment, Climate Change 2001, presented quite a different picture of the Earth’s climate in the last one thousand years. The report prominently displayed a graph based on a new study, compiled by a newly minted Ph.D. named Michael Mann. Dr. Mann used tree rings as a basis for assessing northern hemispheric temperature changes going back to the year 1,000 AD, then crudely grafted the rising surface temperature record of the twentieth century (itself in large part a product of urban “heat islands” produced by asphalt-covered surfaces) onto the pre-1900 tree-ring record. This was like comparing apples to oranges, and therefore not good science, but the effect was visually dramatic.

Gone were the difficult-to-explain medieval warming and the inconvenient Little Ice Age that the other data indicate. Instead, Mann’s graph suggested nine-hundred years of global temperatures trending ever-so-slightly downward—until about 1910. Then, twentieth-century temperatures seemed to rocket upward out of control. The Mann graph became infamous in scientific circles as “the hockey stick,” which it resembles.

The Clinton Administration quickly picked up the Mann graph and featured it as the first graph in the U.S. National Assessment of the Potential of Climate Variability and Change (1999). In fact, the U.S. National Assessment went even further than the IPCC, presenting the Mann graph not as a climate record of the Northern Hemisphere but as a global climate record.

In a triumph of politicized “research,” the global warming movement’s theoretical computer models had been reinforced by a theoretical temperature record.

Reality Check:

“Nothing illustrates the inadequacy of present climate models as graphically as the so-called National Assessment of Climate Change, published by the Clinton Administration to illustrate the impact of a future warming in different regions of the U.S. The strategic error made by the promoters of the NACC was to use two climate models instead of just one. In half of the eighteen regions these give opposite results; in the rest, they diverge widely. For example, one model predicts that greenhouse warming will turn North Dakota into a desert; the other turns it into a swamp.” —Dr. Fred Singer, chairman emeritus of environmental sciences, University of Virginia and now Director of the Science In the Environment Policy Project.

The Mann study gave the IPCC a clear response to the historical variability of temperature: It never happened. Numerous “researchers” immediately began suggesting that the medieval and Roman warmings, and their intervening cold periods, had been “Europe-only” events.

Dozens of other researchers, however, began bringing forth research confirming that the medieval warming and the Little Ice Age had been global. For example: studies conducted in 1994 and 1999 by two different scientists confirm the impact of the medieval warming and the Little Ice Age in South America (See “Tree-ring and Glacial Evidence for the Medieval Warm Epoch and the Little Ice Age in Southern South America,” Climate Change 26: 183-97, 1994; and “Climatic Fluctuations in the Central Region of Argentina in the Last 1000 Years,” Quaternary International 62, p. 35-37, 1999).

A coral-reef core from Madagascar dating back to 1640 AD clearly recorded the impact of the Little Ice Age on the eastern edge of Africa and the western edge of the Indian Ocean (See “Stable Isotope Record from Holocene Reef Corals, Western Indian Ocean,” Journal of the Conference Abstracts, v. 4 No.1, Symposium BO2).

Researchers in Tibet derived a two-thousand-year temperature history from an ice-core they retrieved from the Dasupu glacier, located in the central Himalayas. They found temperature in the first century AD “was low and followed by a significant increase until 730 AD,” whereupon it “reached its maximum during 730–950 AD, then it lowered again, which persisted until 1850 AD,” after which “temperature has increased gradually to its present levels” (See “Temperature and methane records over the last 2 ka in Dasuopu ice core” Science in China [Series D] 45: 1068-1074. As reviewed in the March 19, 2003 Center for the Study of Carbon Dioxide and Global Change). In other words, Tibet experienced the same Dark Ages Cold Period, Medieval Warm Period, Little Ice Age, and, at the very end of the record, Modern Warm Period, that effected Europe and apparently the entire globe.

Causes of Climate Change

Many scientists have been arguing for years that the Earth’s climate variability is related to the sun. Our most important evidence is a set of direct sunspot observations going back to the year 1600 AD, which allow us to compare sunspot activity with the Earth’s climate.

The most striking feature of the four-hundred-year sunspot record is a seventy-year period during which there were virtually no sunspots at all. That period is called the Maunder Minimum. It began in 1640 and ended in 1710—the low-temperature nadir of the Little Ice Age—absolutely linking the absence of sunspots (low solar activity) with low temperatures on Earth.

When we use carbon-14 isotopes (which are predominantly used in carbon dating) as a proxy for solar activity before 1600, they show a high level of solar activity during the medieval warming—and a reduced level of solar activity during a cold period (the Sporer Minimum) around 1350 AD.

A large body of recent research indicates that changes in the solar spectrum (toward ultra-violet instead of infra-red) also impact Earth’s climate (See “The Solar Spectral Irradiance Since 1700,” Geophysical Research Letters, v. 27, no. 14, p. 2157, July 15, 2000 and Lean, J., “Evolution of the Sun’s Spectral Irradiance Since the Maunder Minimum,” Geophysical Research Letters, vol. 27, no. 16, p. 2425, August 15, 2000). The enhanced ultra-violet may affect the ozone layer and other atmospheric chemistry to amplify any warming. Moreover, changes in the magnetic activity on the sun may influence cosmic radiation reaching the Earth, which in turn would modulate low-level cloudiness—and therefore temperature (See “Influence of Cosmic Rays on Earth’s Climate,” Physical Review Letters, v. 81, no. 22, p. 5027, November 30, 1998).

According to Dr. Sally Baliunas of the Harvard-Smithsonian Center for Astrophysics, “Twentieth-century temperature changes show a strong correlation with the sun’s changing energy output. . . . The low magnetism of the seventeenth century . . . coincides with the coldest century of the last millennium, and there is sustained high magnetism in the latter twentieth century [when temperatures rose]” (See “A Scientist’s Rebuttal to the Global Warming Mantra,” presented at Hillsdale College, February 5, 2002).

Until 2001, in fact, the evidence for man-made global warming looked very weak. The Mann graph changed that for a short time.

Now, again, history has spoken.

In the November 16, 2001, issue of the journal Science, an article by Richard Kerr noted, “Paleo-oceanographer Gerard Bond and his colleagues report that the climate of the northern North Atlantic has warmed and cooled nine times in the past 12,000 years in step with the waxing and waning of the sun.” It should be emphasized that these temperature cycles were independent of carbon-dioxide levels

Dr. Bond and a team from the Lamont-Doherty Earth Observatory (affiliated with Columbia University) produced a rare combination of long, continuous, and highly detailed records of both the Earth’s changing climate and solar activity, which are available in the same issue of Science. Bond’s climate record is a laborious accounting of the rocky debris carved by ice from the shores of Canada and Greenland that eventually dropped onto the floor of the northern North Atlantic. His team found that iceberg debris jumped in abundance every 1,500 years or so, indicating that much more ice was present during those regular periods.

“The Bond et al. data are sufficiently convincing that [solar variability] is now the leading hypothesis to explain the roughly 1,500-year oscillation of the climate seen since the last ice age,” glaciologist Richard Alley of Pennsylvania State University told Kerr.

There is still more evidence to support the natural-cycle theory of global climate change. Climate researchers have long recognized that the world’s official thermometer readings have been partially determined by their locations, many of them at official buildings and airports in urban heat islands. Even a village of one thousand people can raise its own temperature reading by 2 to 2.5 degrees Centigrade (See “City Size and the Urban Heat Island,” Atmospheric Environment 7: 769-779). Now, a 2003 study from the University of Maryland estimates that urban expansion and more intensive farming in the United States during the past forty years may account for up to half of the observed “warming” of the Earth’s surface. “Our estimates are that land-use changes in the United States since the 1960s resulted in a rise of over 0.2 degrees Fahrenheit in the mean surface temperature, an estimate twice as high as those of previous studies,” says Dr. Eugenia Kalnay, co-author with Dr. Ming Cai of “Estimating the Impact of Urbanization and Land Use on U.S. Surface Temperature Trends: Preliminary Report,” published in the May 29, 2003, issue of the journal Nature.

Drs. Kalnay and Cai compared trends in surface-temperature measurements taken at nearly two thousand surface weather stations around the United States to trends based on data from U.S. satellite and weather-balloon programs.

In addition, a retired California climatologist named James Goodrich simply divided California’s weather stations into three groups, and plotted their temperature records by population density. In the last one hundred years, California counties with populations exceeding one million have experienced a rising temperature trend; counties with one hundred thousand to a million people have had slightly higher temperatures; and low-population counties have experienced no increase in temperature (See “Global Warming: Scientific Fact or Fiction?” The Independent Policy Forum, February 15, 2000). It is highly unlikely that these different temperature patterns within the same state are due to changes in the Earth’s atmosphere.

Fear Factor

The scariest thing in the global-warming scenarios is the specter of rising sea levels and flooding in London, Calcutta, and perhaps New York City. If the Earth warmed enough, the water would expand, and the polar ice caps could melt. Alarmists warn that sea levels could rise a disastrous fifteen to twenty feet.

However, warming would also evaporate more water from the oceans, which would come down in the Arctic and Antarctic as snow and rain—adding to the ice. Ice accumulation would lower the sea level. The question is, which phenomenon will be stronger, the evaporation or the ice accumulation?

Here, too, science has given us recent and encouraging real-world data. Howard Conway from the University of Washington and his research team reported in Science (October 10, 1999) that the West Antarctic Ice Sheet has been melting at about its present rate since the end of the great Ice Age 15,000 years ago. Sea levels have risen about three hundred feet since then, though more slowly as the amount of glacial ice has declined. It would take another seven thousand years to melt it all at the present rate.

Dr. John Christy says of sea level rise, “In the past one-hundred-fifty years, sea level has risen at a rate of six inches (plus or minus four inches) per century and is apparently not accelerating . . . there is still more land ice available for melting, implying continued sea-level rise with or without climate change” (See Dr. Christy’s Congressional testimony, May 13, 2003).

The truth is, Greenpeace activists believe that a world without power plants would be wonderful, whether the “greenhouse effect” is real or not. Europeans have already saddled themselves with high energy taxes, and would love, for competitive reasons, to have the United States hamper itself in the same way. (A barrel of oil that may bring Kuwait $30 in taxes brings the British government about $150.) Emotionalists will remain unconvinced by the Earth’s reassuring messages of moderate, cyclical warming and cooling. They will likely ask, “Why should we take a chance? Why don’t we just cut our energy use, and then we won’t be sorry no matter what happens?”

If, however, we believe what the Earth is saying, rather than what computer models claim, we will not accept the harsh energy cutbacks of the Kyoto Protocol. They would mean many more human deaths in the Third World and fewer, less-attractive lifestyles for our children—without making much impact on global warming.