Full of hot air: a climate alarmist takes on "criminals against humanity".

Boiling Point: How Politicians, Big oil and Coal, Journalists and Activists Are Fueling the Climate Crisis--And What We Can Do to Avert the Disaster, by Ross Gelbspan, New York: Basic Books, 254 pages, $22

Ross Gelbspan and I agree about one thing: The Kyoto Treaty, the international greenhouse gas agreement that took effect in February, will not accomplish much. Even if the U.S. ratified the treaty, the resulting cuts in carbon dioxide emissions--about percent below 1990 levels in developed countries during the next seven years--would be far too modest to keep the air's C[O.sub.2] content from rising.

Gelbspan and I disagree about the likely consequences of that failure. In Boiling Point, the former Boston Globe reporter predicts "disaster"--including mega-droughts, monsoons, refugees, a "Northern hemisphere deep freeze," malaria and dengue epidemics, "not even enough [water] to drink," and "far more allergies"--due to "escalating instability of the climate system."

Gelbspan, who wrote the similar 1997 book The Heat Is On: The Climate Crisis, the Cover-Up, the Prescription, says it's "excruciating" to watch "the planet fall apart piece by piece in the face of pathological denial," and he calls his book "a last-gasp attempt to break through the monstrous indifference of Americans to the fact that the planet is caving in around us." Skeptics who consider this scenario implausible are "Criminals Against Humanity"--the heading of a chapter that briefly (and inaccurately) describes my own work, which deals with local ecosystem change during past centuries. He calls for "rewiring the planet" to achieve "optimal calibration of competition and cooperation that would maximize our energy and creativity" while extending "the baseline conditions for peace--peace among people, and peace between people and nature."

Gelbspan thus exemplifies the M.O. of climate alarmists who portray the most extreme predictions as mainstream science without noting the uncertainties surrounding them, dismiss objections as financially or politically motivated, and insist there is no choice but to re-engineer the world according to their plan. These strident voices help shape the popular conception of what human-produced greenhouse gases are doing to the planet and what is required to prevent a Day After Tomorrow catastrophe. Their approach, which closes off investigation and shuts down debate through scaremongering and ad hominem attacks, is anti-scientific.

Despite his overwrought warnings, Gelbspan is keen to claim the mantle of science. He threads Boiling Point with supposedly science-based chapters (printed entirely in readerunfriendly italics) called "Snapshots of the Warming." Among other things, these chapters depict glacier and ice sheet changes as harbingers of catastrophe. Yet Antarctica, by far the most massive ice sheet on the planet, has on balance gained mass during the period of recent measurements, 1992 to 2003; instrument records show a net cooling trend between 1966 and 2000. (The Antarctic Peninsula has experienced a warming trend during the last several decades, but it represents just 2 percent of the continent's land mass.) Measurements of the mass of the Greenland ice sheet, the largest in the Northern Hemisphere, are uncertain and may indicate slight shrinkage or growth. Thermometer measurements at the summit of the ice sheet show a recent cooling trend in summer, the season of ice melt. Mountain glaciers also tell a complex stow; many retreated rapidly in the 19th century, well before the emission of most of the carbon dioxide from energy use. A few maritime glaciers have recently expanded.

Gelbspan notes that "the vast majority of the scientific papers on climate change are quite accessible if one is willing to take the time to read them." That implies a standard of scholarship unmet by the book's army of secondary sources, which include newspapers, magazines, wire services, and activist reports.

Gelbspan is also careless in his description of those who disagree with him. He fails to explain that the "greenhouse skeptics" he cites--those "criminals against humanity" accept that the industrial emission of C[O.sub.2] and other greenhouse gases has contributed to a warming trend during the last century. What remains at issue is the extent of this contribution and the magnitude of warming that can be expected during the next century. Computer simulations of uncertain reliability indicate that by 2100 the globally averaged surface temperature will rise approximately 2.5 degrees Celsius, which would seem to require a wholesale switch to nuclear power in the next few decades to avoid the devastation of energy poverty. But other lines of evidence suggest a change of I degree or less, which would be comparable to past natural change, making the transition to 21st-century energy technologies much more affordable. Boiling Point obscures this ongoing debate by repeatedly appealing to a nonexistent scientific consensus.

Gelbspan portrays dissent from his view of climate change as evidence of the fossil fuel industry's corrupting influence, which apparently extends to scientists, journalists, the current administration, even labor union leaders and environmental activists. Yet Boiling Point does not consider the financial, ideological, and personal interests that favor alarmism, such as the desire by scientists for more research funding; by activists for more donations, media attention, and political relevance; by journalists for better play and bigger book advances. (Such issues are considered in two books by active climate researchers that also offer succinct scientific reviews of alarmist news reports: Meltdown, by Patrick J. Michaels, and Taken by Storm, by Christopher Essex and Ross McKitrick.) The existence of nonscientific motives does not tell us which side is right; only careful consideration of the evidence can do that.

While Boiling Point alludes to scientific uncertainties concerning the "role of clouds, future rates of warming, and specific impact in particular geographic areas, to name a few [issues]," Gelbspan immediately redirects focus by declaring that "the overwhelming predominance of climate research today focuses on the [ecosystem] impacts of warming." If

so, climate research has misplaced priorities. In fact, however, many researchers refuse to skip the hard work of achieving a scientifically sound understanding of climate change, a requisite for accurately estimating its impact.

Climate is a complex, dynamic system that involves the oceans, the atmosphere, biota, ice, and land, which interact with each other in multifaceted ways. An accurate computer simulation of climate does not yet exist. Quantitative impacts of natural and anthropogenic influences, of which the enhanced greenhouse effect is one, are works in progress.

To get a sense of the scientific tasks involved, consider some anthropogenic climate influences aside from greenhouse gases. Farming affects nearby soil moisture content, the reflectivity of sunlight, and other factors that may in turn affect local temperature and precipitation. Those local impacts, through complex physical processes, may produce wider climate change. Urbanization (pavement, buildings, and machinery giving off heat) has long been recognized as a source of artificially elevated local temperature. Aerosols emitted by industrial (and natural) sources have both cooling and warming properties. All those anthropogenic causes are distinct from the enhanced greenhouse effect and occur along with ever-present natural variability, which is also a topic of intense research.

Still, there are a couple of points on which scientists, including most skeptics, agree: I) Surface temperature, measured by thermometers and averaged over the globe, has risen about 0.6 degree Celsius since the mid-to-late 19th century. The record shows three trends: a sharp warming trend until around 1940, no warming trend or a slight cooling trend until the 1970s, and a warming trend beginning in the late 1970s. Note, however, that good measurements with few breaks in the record exist for only about 20 percent of the globe, with most of the southern oceans and Antarctica inadequately sampled. In some locations the 19th century ended a several-centuries-long cold period called the Little Ice Age, the waning of which may explain some of the warming. Moreover, globally averaged temperature is a number of little value in estimating local ecosystem response because temperature change has specific local influences and local effects.

2) The air's carbon dioxide content has increased by approximately a third during the last 200 years. Beyond carbon dioxide, other greenhouse gases (notably methane) have also been emitted by human activities. Put together, the energy added to the air by all human-produced green-house gases would be equivalent to increasing the air's carbon dioxide content alone by roughly two-thirds. The increase, though, has not been steady. Most of the gases have been added to the air in the last half-century, so they cannot have driven most of the warming trend observed in the early 20th century. The surface trend in the last decades of the 20th century was about 0.17 degree Celsius per decade. Contrary to Gelbspan, who refers to an "escalating pace of climate change," the warming trend has been steady.

If the recent surface warning trend were entirely ascribed to the human-produced greenhouse effect, the warming trend over a century would be modest, about 1.7 degrees Celsius. Once the observed surface warming trend is apportioned among natural and anthropogenic influences that have yet to be reliably quantified, the anthropogenic greenhouse effect could be further downsized. Modest warming would make the social revolution in moving away from fossil fuel use more affordable as technology advances and wealth rises.

According to most climate simulations, the enhanced greenhouse effect should have produced a sharper warming trend during the last several decades in the low troposphere the layer of air from just above the surface to about eight kilometers up than on the surface. Using data sets from a series of satellites and weather balloons, University of Alabama in Huntsville climatologists John Christy and Roy Spencer have found that the low troposphere has warmed less than the surface. Resolving that discrepancy may improve climate simulations.

There is little on this critical topic in Boiling Point, except for an oblique reference to Christy, described as one of "several longtime climate 'skeptics'" who "had long cited satellite records to downplay the reality of climate change." Gelbspan says "the satellite argument fell apart in 1998," when independent researchers applied an estimate for expected decays in satellite orbits and found "a distinct warming."

In fact, Christy and Spencer have never minimized "the reality of climate change." They immediately investigated and applied the correction found in 1998 for decaying satellite orbits, an adjustment that did tend to raise the already present warming trend (an effect that was partly caused by temporary warmth from the 1997-98 El Nino condition in the Pacific Ocean, which occurred at what was then the record's end point). Christy and Spencer also found previously unnoticed corrections, related to improper instrument calibration. But not all of the corrections were positive, so the combination of changes had little net impact. A 2005 correction by independent researchers slightly increased the warming trend, still leaving it within the prior estimate's margin of error.

Christy and Spencer have fully disclosed their data and methods of analysis in the scientific literature so that other scientists can reproduce their results. To date, the temperature trend in the low troposphere, independently confirmed by satellite and balloon measurements, shows a statistically significant warming of 0.1 degree Celsius per decade, substantially smaller than the warming predicted in computer simulations of the enhanced greenhouse effect.

Gelbspan also downplays the uncertainties about climate change by citing material that he claims validates his alarmist views. He cites, for example, the science volume of the 2001 Third Assessment Report from the United Nations' Intergovernmental Panel on Climate Change (IPCC). This 881-page tome, a worthy overview of a wide body of work related to climate, counts 637 "authors," excluding reviewers, and says "many hundreds of scientists participated," although many contributed to just a few pages on their areas of expertise. Although reviewed, the science volume cannot be said to have undergone what is commonly meant by peer review. Most nonspecialists consult and quote only the 20-page "Summary for Policymakers" (SPM), which also does not meet those standards.

Gelbspan says a 2001 study from the National

Academy of Sciences "not only affirmed the findings of the IPCC but indicated that the IPCC may have even understated the magnitude of some coming impacts." The NAS studied only the SPM. In the words of MIT climatologist Richard Lindzen, one of the NAS study's authors. "The SPM ... is commonly presented as the consensus of thousands of the world's foremost climate scientists. In fact, it is no such thing. Largely for that reason, the NAS panel concluded that the SPM does not provide suitable guidance for the U.S. government." Lindzen adds, "Our primary conclusion was that despite some knowledge and agreement, the science is by no means settled.... [The] SPM has a strong tendency to disguise uncertainty, and conjures up some scary scenarios for which there is no evidence."

Gelbspan also cites the 2000 U.S. National Assessment (USNA), produced by scientists who commendably sought, in their words, to "synthesize, evaluate, and report on what we presently know about the potential climate variability and change for the U.S. in the 21st century." The report used projections from two advanced, computer-based descriptions of climate that were also included in the IPCC report, one from the Hadley Centre in the U.K. and the other from the Canadian Climate Center. The idea was that comparing two models "helps capture a sense of the range of conditions that may be plausible in the future." Compared to several available models, the Canadian one yields more extreme temperature predictions, while the British one yields more extreme precipitation predictions.

In science what sounds plausible makes a good start, but it remains speculation until it survives tests against well-measured reality. Both USNA simulations give inaccurate results for current conditions in the U.S., which has relatively good instrument records. For example, the

Great Lakes and Hudson Bay area can be too warm by 5 degrees Celsius in winter, while the Southwest is too cold by 5 degrees in winter. In the Central Plains, simulated summers are too hot by 2 to 6 degrees Celsius. Incorrect seasonal temperatures, in turn, affect rainfall and drought estimates. In some regions the results from each model are wrong--in opposite directions--compared to reliable measurements, indicating that important physical processes are poorly modeled in the simulations. In a test of both USNA computer models during the report's review process, University of Virginia climatologist Patrick Michaels (one of the skeptics attacked in Boiling Point) and his colleagues found the simulations of past U.S. temperatures were no more accurate than rolling dice.

Yet Gelbspan dismisses uncertainties in forecasts and implies that some of the scariest effects already have happened. "One of the first signs of early-stage [anthropogenic] global warming," he asserts, "is an increase in weather extremes--longer droughts, more heat waves, more severe storms, and much more intense, severe dumps of rain and snow." Here and elsewhere in the book he cites a string of irrelevant weather disaster stories from around the world. Record-busting weather has to be put in the context of records that are generally too short to say much that is scientifically meaningful. As the summary of the IPCC's Third Assessment Report notes, "Some important aspects of climate appear not to have changed.... Changes globally in tropical and extratropical storm intensity and frequency are dominated by interdecadal to multi-decadal variations, with no significant trends evident over the 20th century."

Gelbspan claims "the physics behind the altered drought and rainfall patterns are not extraordinarily complicated." Researchers disagree; they find precipitation one of the most difficult variables to get correct in computer simulations. A small error in precipitation has wide-ranging effects on many other variables because air moisture is related to many important processes, such as those involving clouds, soil moisture, vegetation, and temperature. "As the atmosphere warms," Gelbspan continues, "it accelerates the evaporation of surface waters.... The heated air expands to hold more water.When the normal turbulence comes through the atmosphere, it results in much more intense downpours." Whatever "normal turbulence" may be, Gelbspan's sketch is physically incorrect and logically inconsistent: More precipitation would remove moisture from the air, thus reducing the alarming warming trends presumed in simulations to derive from excess water vapor. As for accurately forecasting trends in extreme weather, the IPCC's summary notes that "very small scale phenomena, such as thunderstorms, tornadoes, hail and lightening, are not simulated in climate models."

Along with improve knowledge of multiple influences on the recent surface warming trend have come indications that warming trends for the next 100 years have been exaggerated. One reason is that "story lines" (the IPCC's term) of the energy and social future that feed into climate simulations speculate on the high end of reality. The growth rate of the air's carbon dioxide content, for example, has been constant since approximately 1975 and smaller than that assumed by the IPCC. World population, a factor in energy demand, has been revised downward. In the 2002 U.N. Mid-Value Forecast, population grows to a steady 9 billion people, where it remains from 2050 to 2075, and declines thereafter. The IPCC generally assumes population growth throughout the 21st century to about H billion people. Likewise, the IPCC assumes per capita carbon dioxide emission will increase, but it has been declining worldwide, despite economic growth. Economist Davis Henderson and statistician Ian Castles have worked to improve the IPCC story lines. One of their criticisms is that projecting future GDPs based on recent exchange rates rather than purchasing power parity leads to overestimates of fossil fuel consumption and therefore of future temperature.

In 2002 NASA climate researcher James Hansen, credited with broadening public concern about the air's increased carbon dioxide content through congressional testimony in 1988, wrote, "It is noteworthy that the current IPCC [greenhouse gas emission] scenarios have a growth rate in the 1990s that is almost double the observed rate," which he said "is consistent with their failure to emphasize data." In 2001 Hansen and a co-researcher had published a study that adjusted the exaggerated emission scenarios. They also considered the impact of technologically achievable reductions in air pollutants such as near-surface ozone and black carbon (soot) that are now recognized as potential warming agents. (A 2005 paper co-authored by Hansen suggests that soot from industry and biomass burning in Eurasia is a significant factor in recent Arctic ice melt.) In the 2001 study, Hansen and his co-author predicted "additional warming in the next 50 years of 3/4 [degrees]C [+ or -][degrees]C.'" That estimate, which falls near the bottom of the IPCC's forecasts, undercuts alarmism with technological optimism. But the Kyoto Treaty does not require the sort of clean-up that Hansen has in mind, which seems inexpensive and healthful on its own merits, in contrast to dramatic carbon dioxide cuts.

Joining skeptics such as Patrick Michaels, who previously had published similar estimates of future warming trends, Hansen said in 2003 that "emphasis on extreme scenarios may have been appropriate at one time, when the public and decision makers were relatively unaware of the global warming issue.... Now, however, the need is for demonstrably objective climate forcing scenarios consistent with what is realistic." Gelbspan, like other climate alarmists, refuses to heed that call for realism, insisting that the evidence supporting his extreme scenarios is "robust," the effects already "visible."

Anyone who disagrees, he implies, is either a crank or a corporate flack. As MIT's Lindzen notes, "It is crucially important that we preserve the integrity of science as a tool for the effective assessment and understanding of nature." If Gelbspan's attitude prevails, something other than science will inform the public debate on climate change, crippling our ability to understand and prepare for nature's ever-present weather and climate catastrophes.

Sallie Baliunas ([e-mail]), an astrophysicist, is the environmental science host of TechCentralStation.com.