Rushing to Judgment (Global Warming Questioned

Is Earth warming? The planet has warmed since the mid-1800s, but before that it cooled for more than five centuries. Cycles of warming and cooling have been part of Earth’s natural climate history for millions of years. So what is the global warming debate about? It’s about the proposition that human use of fossil fuels has contributed significantly to the past century’s warming, and that expected future warming may have catastrophic global consequences. But hard evidence for this human contribution simply does not exist; the evidence we have is suggestive at best. Does that mean the human effects are not occurring? Not necessarily. But media coverage of global warming has been so alarmist that it fails to convey how flimsy the evidence really is. Most people don’t realize that many strong statements about a human contribution to global warming are based more on politics than on science. Indeed, the climate change issue has become so highly politicized that its scientific and political aspects are now almost indistinguishable. The United Nations Intergovernmental Panel on Climate Change (IPCC), upon which governments everywhere have depended for the best scientific information, has been transformed from a bona fide effort in international scientific cooperation into what one of its leading participants terms “a hybrid scientific/political organization.”

Yet apart from the overheated politics, climate change remains a fascinating and important scientific subject. Climate dynamics and climate history are extraordinarily complex, and despite intensive study for decades, scientists are not yet able to explain satisfactorily such basic phenomena as extreme weather events (hurricanes, tornadoes, droughts), El Niño variations, historical climate cycles, and trends of atmospheric temperatures. The scientific uncertainties about all these matters are great, and not surprisingly, competent scientists disagree in their interpretations of what is and is not known. In the current politicized atmosphere, however, legitimate scientific differences about climate change have been lost in the noise of politics.

For some, global warming has become the ultimate symbol of pessimism about the environmental future. Writer Bill McKibben, for example, says, “If we had to pick one problem to obsess about over the next 50 years, we’d do well to make it carbon dioxide.” I believe that we’d be far wiser to obsess about poverty than about carbon dioxide.

Fossil fuels (coal, oil, and natural gas) are the major culprits of the global warming controversy and happen also to be the principal energy sources for both rich and poor countries. Governments of the industrial countries have generally accepted the position, promoted by the IPCC, that humankind’s use of fossil fuels is a major contributor to global warming, and in 1997 they forged an international agreement (the Kyoto Climate Change Protocol) mandating that worldwide fossil fuel use be drastically reduced as a precaution against future warming. In contrast, the developing nations for the most part do not accept global warming as a high-priority issue and, as yet, are not subject to the Kyoto agreement. Thus, the affluent nations and the developing nations have set themselves on a collision course over environmental policy relating to fossil fuel use.

The debate about global warming focuses on carbon dioxide, a gas emitted into the atmosphere when fossil fuels are burned. Environmentalists generally label carbon dioxide as a pollutant; the Sierra Club, for example, in referring to carbon dioxide, states that “we are choking our planet in a cloud of this pollution.” But to introduce the term pollution in this context is misleading because carbon dioxide is neither scientifically nor legally considered a pollutant. Though present in Earth’s atmosphere in small amounts, carbon dioxide plays an essential role in maintaining life and as part of Earth’s temperature control system.

Those who have had the pleasure of an elementary chemistry course will recall that carbon dioxide is one of the two main products of the combustion in air of any fossil fuel, the other being water. These products are generally emitted into the atmosphere, no matter whether the combustion takes place in power plants, household gas stoves and heaters, manufacturing facilities, automobiles, or other sources. The core scientific issue of the global warming debate is the extent to which atmospheric carbon dioxide from fossil fuel burning affects global climate.

When residing in the atmosphere, carbon dioxide and water vapor are called “greenhouse gases,” so named because they trap some of Earth’s heat in the same way that the glass canopy of a greenhouse prevents some of its internal heat from escaping, thereby warming the interior of the greenhouse. By this type of heating, greenhouse gases occurring naturally in the atmosphere perform a critical function. In fact, without greenhouse gases Earth would be too cold, all water on the planet would be frozen, and life as we know it would never have developed. In addition to its role in greenhouse warming, carbon dioxide is essential for plant physiology; without it, all plant life would die.

A number of greenhouse gases other than carbon dioxide and water vapor occur naturally in Earth’s atmosphere and have been there for millennia. What’s new is that during the industrial era, humankind’s burning of fossil fuels has been adding carbon dioxide to the atmospheric mix of greenhouse gases over and above the amounts naturally present. The preindustrial level of 287 parts per million (ppm) of carbon dioxide in the atmosphere has increased almost 30 percent, to 367 ppm (as of 1998).

Few, if any, scientists question the measurements showing that atmospheric carbon dioxide has increased by almost a third. Nor do most scientists question that humans are the cause of most or all of the carbon dioxide increase. Yet the media continually point to these two facts as the major evidence that humans are causing the global warming Earth has recently experienced. The weak link in this argument is that empirical science has not established an unambiguous connection between the carbon dioxide increase and the observed global warming. The real scientific controversy about global warming is not about the presence of additional carbon dioxide in the atmosphere from human activities, which is well established, but about the extent to which that additional carbon dioxide affects climate, now or in the future.

Earth’s climate is constantly changing from natural causes that, for the most part, are not understood. How are we to distinguish the human contribution, which may be very small, from the natural contribution, which may be small or large? Put another way, is the additional carbon dioxide humans are adding to the atmosphere likely to have a measurable effect on global temperature, which is in any case changing continually from natural causes? Or is the temperature effect from the additional carbon dioxide likely to be imperceptible, and therefore unimportant as a practical matter?

Global warming is not something that happened only recently. In Earth’s long history, climate change is the rule rather than the exception, and studies of Earth’s temperature record going back a million years clearly reveal a number of climate cycles—warming and cooling trends. Their causes are multiple—possibly including periodic changes in solar output and variations in Earth’s tilt and orbit—but poorly understood. In recent times, Earth entered a warming period. From thermometer records, we know that the air at Earth’s surface warmed about 0.6ºC over the period from the 1860s to the present. The observed warming, however, does not correlate well with the growth in fossil fuel use during that period. About half of the observed warming took place before 1940, though it was only after 1940 that the amounts of greenhouse gases produced by fossil fuel burning rose rapidly, as a result of the heavy industrial expansions of World War II and the postwar boom (80 percent of the carbon dioxide from human activities was added to the air after 1940).

Surprisingly, from about 1940 until about 1980, during a period of rapid increase in fossil fuel burning, global surface temperatures actually displayed a slight cooling trend rather than an acceleration of the warming trend that would have been expected from greenhouse gases. During the 1970s some scientists even became concerned about the possibility of a new ice age from an extended period of global cooling (a report of the U.S. National Academy of Sciences reflected that concern). Physicist Freeman Dyson notes that “the onset of the next ice age [would be] a far more severe catastrophe than anything associated with warming.”

Earth’s cooling trend did not continue beyond 1980, but neither has there been an unambiguous warming trend. Since 1980, precise temperature measurements have been made in Earth’s atmosphere and on its surface, but the results do not agree. The surface air measurements indicate significant warming (0.25 to 0.4ºC), but the atmospheric measurements show very little, if any, warming.

Briefly, then, the record is this: From 1860 to 1940, Earth’s surface warmed about 0.4ºC. Then Earth’s surface cooled about 0.1ºC in the first four decades after 1940 and warmed about 0.3ºC in the next two. For those two most recent decades, temperature measurements of the atmosphere have also been available, and, while these measurements are subject to significant uncertainty, they indicate that the atmosphere’s temperature has remained essentially unchanged. Thus, the actual temperature record does not support the claims widely found in environmental literature and the media that Earth has been steadily warming over the past century. (A new study that may shed more light on this question—one of a number sure to come—has been circulated but is being revised and has not yet been published.)

For the probable disparity between the surface and atmospheric temperature trends of the past 20 years, several explanations have been offered. The first is that large urban centers create artificial heating zones—“heat islands”—that can contribute to an increase of surface temperature (though one analysis concludes that the heat island effect is too small to explain the discrepancy fully). The second explanation is that soot and dust from volcanic eruptions may have contributed to cooling of the atmosphere by blocking the Sun’s heat (though this cooling should have affected both surface and atmospheric temperatures). In the United States, despite the presence of large urban areas, surface cooling after 1930 far exceeded that of Earth as a whole, and the surface temperature has subsequently warmed only to the level of the 1930s.

It’s frequently claimed that the recent increases in surface temperature are uniquely hazardous to Earth’s ecosystems because of the rapidity with which they are occurring—more than 0.1ºC in a decade. That may be true, but some past climate changes were rapid as well. For example, around 14,700 years ago, temperatures in Greenland apparently jumped 5ºC in less than 20 years—almost three times the warming from greenhouse gases predicted to occur in this entire century by the most pessimistic scientists.

Whatever the current rate of surface warming, there is little justification for the view that Earth’s climate should be unchanging, and that any climate change now occurring must have been caused by humans and should therefore be fixed by humans. In fact, as noted earlier, changing climate patterns and cycles have occurred throughout Earth’s history. For millions of years, ice sheets regularly waxed and waned as global heating and cooling processes took place. During the most recent ice age, some 50,000 years ago, ice sheets covered much of North America, northern Europe, and northern Asia. About 12,000 years ago a warming trend began, signaling the start of an interglacial period that continues to this day. This warm period may have peaked 5,000 to 6,000 years ago, when global ice melting accelerated and global temperatures became higher than today’s. Interglacial periods are thought to persist for about 10,000 years, so the next ice age may be coming soon—that is, in 500 to 1,000 years.

Within the current interglacial period, smaller cyclic patterns have emerged. In the most recent millennium, several cycles occurred during which Earth alternately warmed and cooled. There’s evidence for an unusually warm period over at least parts of the globe from the end of the first millennium to about 1300. A mild climate in the Northern Hemisphere during those centuries probably facilitated the migration of Scandinavian peoples to Greenland and Iceland, as well as their first landing on the North American continent, just after 1000. The settlements in Greenland and Iceland thrived for several hundred years but eventually were abandoned when the climate turned colder, after about 1450. The cold period, which lasted until the late 1800s, is often called the Little Ice Age. Agricultural productivity fell, and the mass exodus to North America of many Europeans is attributed at least in part to catastrophic crop failures such as the potato famine in Ireland.

A plausible interpretation of most or all of the observed surface warming over the past century is that Earth is in the process of coming out of the Little Ice Age cold cycle that began 600 years ago. The current warming trend could last for centuries, until the expected arrival of the next ice age, or it could be punctuated by transient warm and cold periods, as were experienced in the recent millennium.

A great deal of global warming rhetoric gives the impression that science has established beyond doubt that the recent warming is mostly due to human activities. But that has not been established. Though human use of fossil fuels might contribute to global warming in the future, there’s no hard scientific evidence that it is already doing so, and the difficulty of establishing a human contribution by empirical observation is formidable. One would need to detect a very small amount of warming caused by human activity in the presence of a much larger background of naturally occurring climate change—a search for the proverbial needle in a haystack.

Still, understanding climate change is by no means beyond science’s reach, and research is proceeding in several complementary ways. Paleoclimatologists have been probing Earth’s past climatic changes and are uncovering exciting new information about Earth’s climate history going back thousands, and even millions, of years. This paleohistory will help eventually to produce a definitive picture of Earth’s evolving climate, and help in turn to clarify the climate changes we’re experiencing in our own era. But we are far from knowing enough to be able to predict what the future may hold for Earth’s climate.

Mindful of the limited empirical knowledge about climate, some climate scientists have been attempting to understand possible future changes by using computer modeling techniques. By running several scenarios, the modelers obtain a set of theoretical projections of how global temperature might change in the future in response to assumed inputs, governed mainly by the levels of fossil fuel use. But like all computer modeling, even state-of-the-art climate modeling has significant limitations. For example, the current models cannot simulate the natural variability of climate over century-long time periods. A further major shortcoming is that they project only gradual climate change, whereas the most serious impacts of climate change could come about from abrupt changes. (A simple analogy is to the abrupt formation of frost, causing leaf damage and plant death, when the ambient air temperature gradually dips below the freezing point.) Given the shortcomings, policymakers should exercise considerable caution in using current climate models as quantitative indicators of future global warming.

Scientists have long been aware that physical factors other than greenhouse gases can influence atmospheric temperature. Among the most important are aerosols—tiny particles (sulfates, black carbon, organic compounds, and so forth) introduced into the atmosphere by a variety of pollution sources, including automobiles and coal-burning electricity generators, as well as by natural sources such as sea spray and desert dust. Some aerosols, such as black carbon, normally contribute to heating of the atmosphere because they absorb the Sun’s heat (though black carbon aerosols residing at high altitudes can actually cool Earth’s surface because they block the Sun’s rays from getting through to it). Other aerosols, composed of sulfates and organic compounds, cool the atmosphere because they reflect or scatter the Sun’s rays away from Earth. Current evidence indicates that aerosols may be responsible for cooling effects at Earth’s surface and warming effects in Earth’s atmosphere. But the impacts of pollution on Earth’s climate are very uncertain. The factors involved are difficult to simulate, but they must be included in computer models if the models are to be useful indicators of future climate. When climate models are finally able to incorporate the full complexity of pollution effects, especially from aerosols, the projected global temperature change could be either higher or lower than current projections, depending on the chemistry, altitude, and geographic region of the particular aerosols involved. Or, it could even be zero.

In addition to pollution, other physical factors that can influence surface and atmospheric temperature are methane (another greenhouse gas), dust from volcanic activity, and changes in cloud cover, ocean circulation patterns, air-sea interactions, and the Sun’s energy output. “The forcings that drive long-term climate change,” concludes James Hansen, one of the pioneers of climate change science, “are not known with an accuracy sufficient to define future climate change. Anthropogenic greenhouse gases, which are well measured, cause a strong positive forcing [warming]. 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.” And as if the physical factors were not challenging enough, the inherent complexity of the climate system will always be present to thwart attempts to predict future climate.

In view of climate’s complexity and the limitations of today’s climate simulations, one might expect that pronouncements as to human culpability for climate change would be made with considerable circumspection, especially pronouncements made in the name of the scientific community. So it was disturbing to many scientists that a summary report of the IPCC issued in 1996 contained the assertion that “the balance of evidence suggests a discernible climate change due to human activities.” The latest IPCC report (2001) goes even further, claiming that “there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” But most of this evidence comes from new computer simulations and does not satisfactorily address either the disparity in the empirical temperature record between surface and atmosphere or the large uncertainties in the contributions of aerosols and other factors. A report issued by the National Academy of Sciences in 2001 says this about the model simulations:

Because of the large and still uncertain level of natural variability inherent in the climate record and the uncertainties in the time histories of the various forcing agents (and presumably aerosols), a causal linkage between the buildup of greenhouse gases in the atmosphere and the observed climate changes during the 20th century cannot be unequivocally established. The fact that the magnitude of the observed warming is large in comparison to natural variability as simulated in climate models is suggestive of such a linkage, but it does not constitute proof of one because the model simulations could be deficient in natural variability on the decadal to century time scale.

These IPCC reports have been adopted as the centerpiece of most current popularizations of global warming in the media and in the environmental literature, and their political impact has been enormous. The 1996 report was the principal basis for government climate policy in most industrial countries, including the United States. The IPCC advised in the report that drastic reductions in the burning of fossil fuels would be required to avoid a disastrous global temperature increase. That advice was the driving force behind the adoption in 1997 of the Kyoto protocol to reduce carbon dioxide emissions in the near future.

In its original form, the protocol had many flaws. First, it exempted developing countries, including China, India, and Brazil, from the emission cutbacks; such countries are increasingly dependent on fossil fuels, and their current greenhouse gas emissions already exceed those of the developed countries. Second, it mandated short-term reductions in fossil fuel use to reach the emission targets without regard to the costs of achieving those targets. Forced cutbacks in fossil fuel use could have severe economic consequences for industrial countries (the protocol would require the United States to cut back its fossil fuel combustion by over 30 percent to reach the targeted reduction of carbon dioxide emissions by 2010), and even greater consequences for poor countries should they ultimately agree to be included in the emissions targets. The costs of the cutbacks would have to be paid up front, whereas the assumed benefits would come only many decades later. Third, the fossil fuel cutbacks mandated by the protocol are too small to be effective—averting, by one estimate, only 0.06ºC of global warming by 2050.

The Kyoto protocol was signed in 1997 by many industrial countries, including the United States, but to have legal status, it must be ratified by nations that together account for 55 percent of global greenhouse gas emissions. As of June 2002, the protocol had been ratified by 73 countries, including Japan and all 15 nations of the European Union. These countries are responsible, in all, for only 36 percent of emissions, but the 55 percent requirement may be met by Russia’s expected ratification. Nonetheless, the treaty is unlikely to have real force without ratification by the United States. The Bush administration opposes the treaty, on the grounds of its likely negative economic impact on America, and has thus far not sought Senate ratification. Even the Clinton administration did not seek ratification, despite its having signed the initial protocol, because it was aware that the U.S. Senate had unanimously adopted a resolution rejecting in principle any climate change treaty that does not include meaningful participation by developing countries.

With the United States retaining its lone dissent, 165 nations agreed in November 2001 to a modified version of Kyoto that would ease the task of reducing carbon dioxide emissions by allowing nations to trade their rights to emit carbon dioxide, and by giving nations credit for the expansion of forests and farmland, which soak up carbon dioxide from the atmosphere. A study by economist William Nordhaus in Science magazine (Nov. 9, 2001) finds that a Kyoto treaty modified along these lines would incur substantial costs, bring little progress toward its objective, and, because of the huge fund transfers that would result from the practice of emissions trading, stir political disputes. Nordhaus concludes that participation in the treaty would have cost the United States some $2.3 trillion over the coming decades—more than twice the combined cost to all other participants. It does not require sympathy with overall U.S. climate change policy to understand the nation’s reluctance to be so unequal a partner in the Kyoto enterprise.

Though the political controversy continues, the science has moved away from its earlier narrow focus on carbon dioxide as a predictor of global warming to an increasing realization that the world’s future climate is likely to be determined by a changing mix of complex and countervailing factors, many of which are not under human control and all of which are insufficiently understood. But regardless of the causes, we do know that Earth’s surface has warmed during the past century. Although we don’t know the extent to which it will warm in the future, or whether it will warm at all, we can’t help but ask a couple of critical questions: How much does global warming matter? What would be the consequences if the global average temperature did actually rise during the current century by, say, some 2ºC?

Some environmentalists have predicted dire consequences from the warming, including extremes of weather, the loss of agricultural productivity, a destructive rise in sea level, and the spread of diseases. Activists press for international commitments much stronger than the Kyoto protocol to reduce the combustion of fossil fuels, and they justify the measures as precautionary. Others counter that the social and economic impacts of forced reductions in fossil fuel use would be more serious than the effects of a temperature rise, which could be small, or even beneficial.

Although the debate over human impacts on climate probably won’t be resolved for decades, a case can be made for adopting a less alarmist view of a warmer world. In any event, the warmer world is already here. In the past 2,500 years, global temperatures have varied by more than 3ºC, and some of the changes have been much more abrupt than the gradual changes projected by the IPCC. During all of recorded history, humans have survived and prospered in climate zones far more different from one another than those that might result from the changes in global temperatures now being discussed.

Those who predict agricultural losses from a warmer climate have most likely got it backwards. Warm periods have historically benefited the development of civilization, and cold periods have been detrimental. For example, the Medieval Warm Period, from about 900 to 1300, facilitated the Viking settlement of Iceland and Greenland, whereas the subsequent Little Ice Age led to crop failures, famines, and disease. Even a small temperature increase brings a longer and more frost-free growing season—an advantage for many farmers, especially those in large, cold countries such as Russia and Canada. Agronomists know that the enrichment of atmospheric carbon dioxide stimulates plant growth and development in greenhouses; such enrichment at the global level might be expected to increase vegetative and biological productivity and water-use efficiency. Studies of the issue from an economic perspective have reached the same conclusion: that moderate global warming would most likely produce net economic benefits, especially for the agriculture and forestry sectors. Of course, such projections are subject to great uncertainty and cannot exclude the possibility that unexpected negative impacts would occur.

As for the concern that warmer temperatures would spread insect-borne diseases such as malaria, dengue fever, and yellow fever, there’s no solid evidence to support it. Although the spread of disease is a complex matter, the main carriers of these diseases—which were common in North America, western Europe, and Russia during the 19th century, when the world was colder than it is today—are most likely humans traveling the globe and insects traveling with people and goods. The strongest ally against future disease is surely not a cold climate but concerted improvement in regional insect control, water quality, and public health. As poverty recedes and people’s living conditions improve in the developing world, the level of disease, and its spread, can be expected to decrease. Paul Reiter, a specialist in insect-borne diseases, puts it this way:

Insect-borne diseases are not diseases of climate but of poverty. Whatever the climate, developing countries will remain at risk until they acquire window screens, air conditioning, modern medicine, and other amenities most Americans take for granted. As a matter of social policy, the best precaution is to improve living standards in general and health infrastructures in particular.

One of the direst (and most highly publicized) predictions of global warming theorists is that greenhouse gas warming will cause sea level to rise and that, as a result, many oceanic islands and lowland areas, such as Bangladesh, may be submerged. But in fact, sea level—which once was low enough to expose a land bridge between Siberia and Alaska—is rising now, and has been rising for thousands of years. Recent analyses suggest that sea level rose at a rate of about one to two centimeters per century (0.4 to 0.8 inch) over the past 3,000 years. Some studies have interpreted direct sea-level measurements made throughout the 20th century to show that the level is now rising at a much faster rate, about 10 to 25 centimeters per century (4 to 10 inches), but other studies conclude that the rate is much lower than that. To whatever extent sea-level rise may have accelerated, the change is thought to have taken place before the period of industrialization.

Before considering whether the ongoing sea-level rise has anything to do with human use of fossil fuels, let’s examine what science has to say about how global temperature change may relate to sea-level change. The matter is more complicated than it first appears. Water expands as it warms, which would contribute to rising sea level. But warming increases the evaporation of ocean water, which could increase the snowfall on the Arctic and Antarctic ice sheets, remove water from the ocean, and lower sea level. The relative importance of these two factors is not known.

We do know from studies of the West Antarctic Ice Sheet that it has been melting continuously since the last great ice age, about 20,000 years ago, and that sea level has been rising ever since. Continued melting of the ice sheet until the next ice age may be inevitable, in which case sea level would rise by 15 to 18 feet when the sheet was completely melted. Other mechanisms have been suggested for natural sea-level rise, including tectonic changes in the shape of the ocean basins. The theoretical computer climate models attribute most of the sea-level rise to thermal expansion of the oceans, and thus they predict that further global temperature increase (presumably from human activities) will accelerate the sea-level rise. But because these models cannot deal adequately with the totality of the natural phenomena involved, their predictions about sea-level rise should be viewed skeptically.

The natural causes of sea-level rise are part of Earth’s evolution. They have nothing to do with human activities, and there’s nothing that humans can do about them. Civilization has always adjusted to such changes, just as it has adjusted to earthquakes and other natural phenomena. This is not to say that adjusting to natural changes is not sometimes painful, but if there’s nothing we can do about certain natural phenomena, we do adjust to them, however painfully. Sea-level rise is, most likely, one of those phenomena over which humans have no control.

Some environmentalists claim that weather-related natural disasters have been increasing in frequency and severity, presumably as a result of human-caused global warming, but the record does not support their claims. On the contrary, several recent statistical studies have found that natural disasters—hurricanes, typhoons, tropical storms, floods, blizzards, wildfires, heat waves, and earthquakes—are not on the increase. The costs of losses from natural disasters are indeed rising, to the dismay of insurance companies and government emergency agencies, but that’s because people in affluent societies construct expensive properties in places vulnerable to natural hazards, such as coastlines, steep hills, and forested areas.

Because society has choices, we must ask what the likely effects would be, on the one hand, if people decided to adjust to climate change, regardless of its causes, and, on the other, if governments implemented drastic policies to attempt to lessen the presumed human contribution to the change. From an economic perspective at least, adjusting to the change would almost surely come out ahead. Several analyses have projected that the overall cost of the worst-case consequences of warming would be no more than about a two percent reduction in world output. Given that average per capita income will probably quadruple during the next century, the potential loss seems small indeed. A recent economic study emphasizing adaptation to climate change indicates that in the market economy of the United States the overall impacts of modest global warming are even likely to be beneficial rather than damaging, though the amount of net benefit would be small, about 0.2 percent of the economy. (We need always to keep in mind the statistical uncertainties inherent in such analyses; there are small probabilities that the benefits or costs could turn out to be much greater than or much less than the most probable outcomes.)

In contrast, the economic costs of governmental actions restricting the use of fossil fuels could be large indeed, as suggested by the Nordhaus study cited earlier on the costs of compliance with the Kyoto treaty. One U.S. government study proposed that a cost-effective way of bringing about fossil fuel reductions would be a combination of carbon taxes and international trading in emissions rights. Emissions rights trading was, in fact, included in the modified Kyoto agreement. But such a trading scheme would result in huge income transfers, as rich nations paid poor nations for emissions quotas that the latter would probably not have used anyway—and it’s not reasonable to assume that rich nations would be willing to do this.

Taking into account the large uncertainties in estimating the future growth of the world economy, and the corresponding growth in fossil fuel use, one group of economists puts the costs of greenhouse gas reduction in the neighborhood of one percent of world output, while another group puts it at around five percent of output. The costs would be considerably higher if large reductions were forced upon the global economy over a short time period, or if, as is likely, the most economically efficient schemes to bring about the reductions were not actually employed. Political economists Henry Jacoby, Ronald Prinn, and Richard Schmalensee put the matter bluntly: “It will be nearly impossible to slow climate warming appreciably without condemning much of the world to poverty, unless energy sources that emit little or no carbon dioxide become competitive with conventional fossil fuels.”

Some global warming has been under way for more than a century, at least partly from natural causes, and the world has been adjusting to it as it did to earlier climate changes. If human activity is finally judged to be adding to the natural warming, the amount of the addition is probably small, and society can adjust to that as well, at relatively low cost or even net benefit. But the industrial nations are not likely to carry out inefficient, Kyoto-type mandated reductions in fossil fuel use on the basis of so incomplete a scientific foundation as currently exists. The costs of so doing could well exceed the potential benefits. Far more effective would be policies and actions by the industrial countries to accelerate the development, in the near term, of technologies that utilize fossil fuels (and all resources) more efficiently and, in the longer term, of technologies that do not require the use of fossil fuels.

If climate science is to have any credibility in the future, its pursuit must be kept separate from global politics. The affluent nations should support research programs that improve the theoretical understanding of climate change, build an empirical database about factors that influence long-term climate change, and increase our understanding of short-term weather dynamics. Such research is fundamental to the greenhouse gas issue. But its rewards may be greater still, for it will also improve our ability to cope with extreme weather events such as hurricanes, tornadoes, and floods, whatever their causes.

Jack M. Hollander is professor emeritus of energy and resources at the University of California, Berkeley. His many books include The Energy-Environment Connection (1992) and The Real Environmental Crisis: Why Poverty, Not Affluence, Is the World’s Number One Enemy (2003), published by the University of California Press, from which this essay has been adapted. Copyright © 2003 by the Regents of the University of California.

indicate if you maintain
a) the majority of CO2 added to the atmosphere since 1850 is from human sources, primarily fossil fuels, or
b) the majority of CO2 added to the atmosphere since 1850 is not anthropogenic.

You left out choice "c)" which you know I maintain.

c) the measured increase in CO2 concentration, whatever its source, is insufficient to induce measureable increase in global temperature.

The issue is not change in CO2.

Variable solar absorption/reflectance(i.e. aldebo) & solar output are the dominant drivers of earths heat balance with water vapor the primary mediator of the earth's greenhouse system.

Minimal CO₂-Temperature correlation with earth's surface temperature, and no causal link, as shown in the many studies cited above in reply #13 above, means nil effect on the earth's heat balance.

Any spectral absorption/reradiation of CO₂ is totally overwhelmed by absorption/re-radiation of H₂0 concentration making up 95% of earth's total greenhouse capacity.

Anthropogenic (man-made) Contribution to the "Greenhouse
Effect," expressed as % of Total (water vapor INCLUDED)

Based on concentrations (ppb) adjusted for heat retention characteristics % of All Greenhouse Gases
% Natural

% Man-made

Water vapor 95.000%
94.999%
0.001%

Carbon Dioxide (CO2) 3.618%
3.502%
0.117%

Methane (CH4) 0.360%
0.294%
0.066%

Nitrous Oxide (N2O) 0.950%
0.903%
0.047%

Misc. gases ( CFC's, etc.) 0.072%
0.025%
0.047%

Total 100.00%
99.72
0.28%

Climate Catastrophe, A spectroscopic Artifact?

"It is hardly to be expected that for CO2 doubling an increment of IR absorption at the 15 µm edges by 0.17% can cause any significant global warming or even a climate catastrophe.
The radiative forcing for doubling can be calculated by using this figure. If we allocate an absorption of 32 W/m² [14] over 180º steradiant to the total integral (area) of the n3 band as observed from satellite measurements (Hanel et al., 1971) and applied to a standard atmosphere, and take an increment of 0.17%, the absorption is 0.054 W/m² - and not 4.3 W/m².
This is roughly 80 times less than IPCC's radiative forcing.
If we allocate 7.2 degC as greenhouse effect for the present CO2 (as asserted by Kondratjew and Moskalenko in J.T. Houghton's book The Global Climate [14]), the doubling effect should be 0.17% which is 0.012 degC only. If we take 1/80 of the 1.2 degC that result from Stefan-Boltzmann's law with a radiative forcing of 4.3 W/m², we get a similar value of 0.015 degC."

Variation in CO₂ concentration is simply not a substantive factor in variation of global temperature of the earth, water vapor overwhelmingly dominates the greenhouse balance.

The UN/IPPC models claim a hair on a dog's tail wags the dog.

You obviously have missed the significance of the following graphical presentation of CO2 vs Surface temperature:

CO2 fell from 7000ppm 600 million years ago to the 320ppm today, variation of earth's temperature, there is nil correlation in response to that change.

Where is the missing runaway greenhouse effect, the (CO2 everything else) multiplier that is the built in presumption of the IPPC Global Climate Models? It does not exist.

I was referring to the OISM hoax survey in this case. I'm glad you didn't post that tripe again.

What survey? There is a petition supported by many in the scientific community in opposition to the claims of Kyoto, & UN/IPCC. The only thing fraudulent is the global warming hype mischaracterizing that petition but by no means countering its claim of "no convincing evidence".

This very debate proves the validity of that claim without a doubt.

Petition Project: http://www.oism.org/pproject/s33p357.htm

During the past 2 years, more than 17,100 basic and applied American scientists, two-thirds with advanced degrees, have signed the Global Warming Petition.

Specifically declaring:
"There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gasses is causing or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate."

Signers of this petition so far include 2,660 physicists, geophysicists, climatologists, meteorologists, oceanographers, and environmental scientists (select this link for a listing of these individuals) who are especially well qualified to evaluate the effects of carbon dioxide on the Earth's atmosphere and climate.
Signers of this petition also include 5,017 scientists whose fields of specialization in chemistry, biochemistry, biology, and other life sciences (select this link for a listing of these individuals) make them especially well qualified to evaluate the effects of carbon dioxide upon the Earth's plant and animal life.
Nearly all of the initial 17,100 scientist signers have technical training suitable for the evaluation of the relevant research data, and many are trained in related fields.

I apologize for "thinking out loud" in your presence, but with my background this note intrigued me:

To the consternation of global warming proponents, the Late Ordovician Period was also an Ice Age, with CO2 concentrations nearly 15 times higher than today-- 5500 ppm. According to greenhouse theory, Earth should have been exceedingly hot. Instead, global temperatures were no warmer than today. Clearly, other factors besides atmospheric carbon influence earth temperatures and global warming.

The reason that I'm thinking out loud is that something we'll return to repeatedly as we consider paleoclimate evidence is the apples-to-oranges comparison trap -- a trap that I'd like to avoid. If we are going to figure out what is happening now and what might happen in the future, we have to make sure that what we are considering is relevant. OK -- there's no doubt that "other factors besides atmospheric carbon [dioxide] influence earth temperatures and global warming". The rate of plate tectonics is a first-order driver over millions of years (something Berner, whom you cite, has studied extensively). But if we are considering climate changes over millenial or shorter timescales, then considering plate tectonic processes is pretty useless. I hope you agree with that.

Having said that, what is known about the Ordovician paleoclimate? Here's a good description, from my Cal-Berkeley friends:

Ordovician: Tectonics and Paleoclimate

Read it at your leisure. Summary: continents were moving around, mountains were rising, ocean currents were totally different tha today, eventually Gondwanaland made it to the South Pole when the Ashgillian glaciation took place. You know how long the Ashgillian was? About 10 million years. All of the Pleistocene glaciations took place in less than 0.5 million years.

So does the fact that CO2 was much, much higher in the Ordovician, when there was an Ice Age, cause me consternation? Not a bit. Because this is an apples-to-oranges comparison; it's virtually meaningless and it does not instruct us regarding processes that are relevant today. Because I know that there are other factors that affect Earth's climate other than CO2, particularly when the timescales under discussion differ by several orders of magnitude. It's also apples-to-oranges in terms of the overall climate setting, i.e., where the continents were, where the ocean currents where, where the continental shelves were, what the ocean chemistry was (note the end of the second paragraph on the linked page), etc.

But there is still an important question regarding whether or not CO2 was a paleoclimate factor. I'll get to that next week. This will be the last post for today and the weekend, but I'll be working on next week's submission in the interim.

I need to know if I first need to prove to you, incontrovertibly, that the increasing CO2 is primarily from human sources (primary among them being fossil fuel burning for energy production).

You don't need to prove anything as the issue is irrelavent, CO2 concentration regardless of source of emmission is increasing, but does not induce substantive increase of temperature with a high water vapor content atmosphere, futhermore, most CO2 is derived from natural sources in any case by a factor of greater than 10 to 1

If you are harboring any sense that there is a possibility that the current trend of increasing CO2 concentrations in the atmosphere is not caused by humans, I need to dispel that completely.

Less than 10% of CO2 emmissions are due to mankind thus less than 10% of any residual effect of increasing CO2 is due to mankind:

Contemporary Climate Change

6.4.1.1. Sources of Atmospheric CO2

Sources of atmospheric CO2 can today be divided into two groups: natural and anthropogenic. Natural sources include the respiration of animals (60Gt per annum) and the surface ocean (90Gt per annum) (Schimel et al., 1995). Anthropogenic sources include the combustion of fossil fuels (power stations and transport) and cement production (5.5Gt per annum)and land-use changes (mainly deforestation) (1.6Gt per annum)

Heat sinks do not distinguish anthropogenic CO2 from natural sources.

6.4.1.2. Sinks of Atmospheric CO2

The surface ocean also acts as a natural sink for atmospheric CO2, with an annual removal flux of 92Gt carbon. The interaction of CO2 between atmosphere and surface ocean was more fully addressed in section 5.3.1.2 (Equations 14 to 17). The other major natural sink is the primary productivity of land vegetation (photosynthesis), which sequesters 61.4Gt carbon every year (Schimel et al., 1995). The regrowth of Northern Hemisphere forests represents the only major anthropogenic sink of atmospheric CO2, although enhanced fertilisation effects due to elevated CO2 concentrations and other climatic feedbacks have also been considered.

BECAUSE... you apparently alluded that the" increasing CO2 concentrations might be a climate effect, i.e., a response to a natural climate trend.

It, without a doubt, is. As a consequence of warming and release of watervapor with warming through variation of aldebo/reflection of solar flux, there is more biomass to produce CO2, greater release of CO2 from solution in oceans and glacial ices ....

You can easily say that a) is correct, and we can move on from there.

a) is incorrect as well as irrelevant due to lack of capacity to effect substantive change in earth's global temperature in comparison to the substantive affects of water vapor, and we can continue from there.

CO2-Temperature Correlations

"(1) correlation does not prove causation, (2) cause must precede effect, and (3) when attempting to evaluate claims of causal relationships between different parameters, it is important to have as much data as possible in order to weed out spurious correlations.

***

Consider, for example, the study of Fischer et al. (1999), who examined trends of atmospheric CO2 and air temperature derived from Antarctic ice core data that extended back in time a quarter of a million years. Over this extended period, the three most dramatic warming events experienced on earth were those associated with the terminations of the last three ice ages; and for each of these climatic transitions, earth's air temperature rose well in advance of any increase in atmospheric CO2. In fact, the air's CO2 content did not begin to rise until 400 to 1,000 years after the planet began to warm. Such findings have been corroborated by Mudelsee (2001), who examined the leads/lags of atmospheric CO2 concentration and air temperature over an even longer time period, finding that variations in atmospheric CO2 concentration lagged behind variations in air temperature by 1,300 to 5,000 years over the past 420,000 years."

[ see also: Indermuhle et al. (2000), Monnin et al. (2001), Yokoyama et al. (2000), Clark and Mix (2000) ]

"Other studies periodically demonstrate a complete uncoupling of CO2 and temperature "

[see: Petit et al. (1999), Staufer et al. (1998), Cheddadi et al., (1998), Raymo et al., 1998, Pagani et al. (1999), Pearson and Palmer (1999), Pearson and Palmer, (2000) ]

"Considered in their entirety, these several results present a truly chaotic picture with respect to any possible effect that variations in atmospheric CO2 concentration may have on global temperature. Clearly, atmospheric CO2 is not the all-important driver of global climate change the climate alarmists make it out to be."

The rate of plate tectonics is a first-order driver over millions of years (something Berner, whom you cite, has studied extensively).

That my friend does not account for the total lack of variation in surface temperature with CO2 across paleological time frames.

So does the fact that CO2 was much, much higher in the Ordovician, when there was an Ice Age, cause me consternation? Not a bit.

Look again, remove the decreases to iceage conditions applicable to the Ordovician etc. tectonic movements. Where is the change that should be in place relating to your supposed CO2 driven warming/cooling? please point it out for us, somehow it seems to escape detection.

According to you, and the UN/IPCC modelers you support, a variation in CO2 should induce a commensurate change in global temperatures by a factor of several times the change that would be induce by CO2 alone. Where are these changes in the paleo-climatic record. Please point them out to us.

CO2 across the 500 million year period varied from 7000ppm down to less than 300ppm in an exponential decay, a factor of 35 to 1 that is about 5 doublings.

Look at the temperature line, flat lined except for occasional excursions into iceage conditions spread out along that flat temperature line.

Where is this alleged variation that should be present due to the 35 to 1 variation in CO2 across that geological record? There should be some evidence of that variation superimposed upon any variation you claim to be due to continental drift.

Taking the UN/IPCC's factors for a CO2 doubling of .75C to 4.5 degrees C according to the reported ranges of their models, we should see a decline of 3.75-12.5 degrees C superimposed on the temperature line below.

No such CO2 induced decline is evident, only declines clearly due to other factors than CO2 concentration are apparent in the data with no evidence of any response to changing CO2 concentrations.

Why? because atmospheric water vapor totally overshadows any marginal effects of CO2.

As pointed out the prior replies, atmospheric CO2 concentration has minimal correlation with the earth's surface temperatures and no causal link as is clearly demonstrated in paleo-climate studies and supported in analysis below:

Climate Catastrophe, A spectroscopic Artifact?

"It is hardly to be expected that for CO2 doubling an increment of IR absorption at the 15 µm edges by 0.17% can cause any significant global warming or even a climate catastrophe.
The radiative forcing for doubling can be calculated by using this figure. If we allocate an absorption of 32 W/m² [14] over 180º steradiant to the total integral (area) of the n3 band as observed from satellite measurements (Hanel et al., 1971) and applied to a standard atmosphere, and take an increment of 0.17%, the absorption is 0.054 W/m² - and not 4.3 W/m².
This is roughly 80 times less than IPCC's radiative forcing.
If we allocate 7.2 degC as greenhouse effect for the present CO2 (as asserted by Kondratjew and Moskalenko in J.T. Houghton's book The Global Climate [14]), the doubling effect should be 0.17% which is 0.012 degC only. If we take 1/80 of the 1.2 degC that result from Stefan-Boltzmann's law with a radiative forcing of 4.3 W/m², we get a similar value of 0.015 degC."

How about looking at the evidence in front of you nose for a change instead of the IPCC hype & flawed computer simulations. There is no CO2 dependant warming crisis.

Having said that, what is known about the Ordovician paleoclimate? Here's a good description, from my Cal-Berkeley friends:

Ordovician: Tectonics and Paleoclimate

Read it at your leisure. Summary: continents were moving around, mountains were rising, ocean currents were totally different tha today, eventually Gondwanaland made it to the South Pole when the Ashgillian glaciation took place. You know how long the Ashgillian was? About 10 million years. All of the Pleistocene glaciations took place in less than 0.5 million years.

Which does not explain the reason for the radical and very rapid GLOBAL cooling at the end of the Ordivician. The article states only that such occurred initiating a mass-extinction.

I suggest you read the following at your leisure which explains not only the rapid onset of the late Ordovician Ice Age, but the distrubution of mass-extinctions that occured as well.

Slow continental drifts do not induce rapid switches into deep iceages from the conditions like that of the Ordovician climate.

Gamma Ray Bursts and other astonomical events involving earths motion through the galaxy offer insight to the Ordovician glaciations and later similar decents in global cooling as well, including the rapid decent into our own Tertiary/Quaternary Ice Age with its repetitive 100kyr interglacial periods with that correlate with earths orbital inclination.

New Scientist article 27 Sept 03: http://www.eurekalert.org/pub_releases/2003-09/ns-dag092403.php

Previous theories blame the two extinctions that occurred in the late Ordovician period on the start and end of an ice age at the time. But it is hard to explain what triggered the ice age itself, which started very suddenly at a time when the climate was quite warm.
Continental changes would have taken too long, and climate models have not been able to replicate the ice age. But a GRB that blocked out the sun could have caused it, points out Pat Brenchley, a retired palaeoecologist from the University of Liverpool, UK, calling the idea" an interesting alternative.

PDF source paper on this subject: Did a gamma-ray burst initiate the late Ordovician mass extinction...,

page 1;

ABSTRACT
At least five times in the history of life, the Earth experienced mass extinctions that
eliminated a large percentage of the biota. Many possible causes have been documented,
and gamma-ray bursts (GRB) may also have contributed. GRB (Mészáros, 2001)
produce a flux of radiation detectable across the observable Universe. A GRB within our
own galaxy could do considerable damage to the Earth's biosphere (Thorsett, 1995;
Scalo & Wheeler, 2002; Dar & DeRújula, 2002). Rate estimates (Thorsett, 1995)
suggest that a number of such GRB may lie within the fossil record. The late Ordovician
mass extinction shows a water-depth dependent extinction pattern that is a natural result
of the attenuation of the strong ultraviolet radiation expected to result from a nearby
GRB. In addition, a GRB would trigger global cooling which is associated with this
mass extinction.

INTRODUCTION AND HYPOTHESIS
As mass extinctions have become well-documented, interest in them has grown, partly
out of concern for our current environmental situation. Extraterrestrial causes have been
more seriously considered in recent years, as the extent of their possible impact becomes
known. It seems likely that a GRB has affected the Earth, and should have had a
substantial effect upon living organisms. We have found patterns of extinction in one
event that match expectations of a GRB-initiated extinction.

*****

page 5;

This extinction has been related to alternating global cooling and warming, each
associated possibly with what may be the two pulses of the late Ordovician mass
extinction (Brenchley et al., 1994; Brenchley et al., 1995; Orth et al., 1986). We do not
dispute the role global cooling may have played in mediating this extinction. Instead, we
emphasize that there is a natural link between GRB and global cooling. There exists a
correlation (Shaviv, 2002) between ice ages and the timing of spiral arm passage, which
has been ascribed to increased cosmic ray flux associated with increased star formation
and supernovae. We note that since GRB probably arise from star-forming regions and
produce opaque nitrogen dioxide in Earth’s atmosphere they provide a mechanism for
global cooling. Paleoclimate modeling (Herrmann and Patzkowsky 2002; Herrmann et
al. 2003) has shown that late Ordovician glaciation would not have proceeded without an
impulse such as reduced solar insolation.

We suggest that the late Ordovician extinction may have been initiated by a GRB. The
oxygen level of the atmosphere was not greatly different from that of the present (Berner
et al., 2003), so that an ozone shield should have been in place. Its destruction would
almost certainly involve similar catastrophic consequences to those observed in modern
organisms (Kiesecker et al., 2001; Hader et al., 2003). A GRB could have triggered the
global cooling, while presenting a host of environmental challenges to life on the planet
through the effects of increased radiation reaching the surface, acid rain, etc., followed
shortly by global cooling; the result: a one, two punch for life on the planet. Notably, the
kind of water depth dependence found in the late Ordovician extinction pattern would
emerge naturally from the attenuation of the UV radiation.

ADDITIONAL ARGUMENT IN SUPPORT OF HYPOTHESIS

Supernovae are known to be correlated, probably going off in chain-reactions of star
formation and detonation, which produce the “superbubbles” found in the interstellar
medium. Given the probable linkage between GRB and supernovae, proximity to one
event would suggest an enhanced probability of a second. The late Ordovician extinction
seems to have occurred in two pulses about 1My apart.

IMPLICATIONS

This hypothesis suggests that a closer look be taken at the geographical distribution of
extinctions in the late Ordovician along the line of what Anstey et al. (2003) have done.
A strong initial muon burst might seriously irradiate only one side of the Earth to
considerable ocean depth, while the other side would mostly be irradiated by post-burst
solar UV due to ozone loss. This suggests an extinction pattern emphasizing depth-dependent
extinction predominantly in one hemisphere, with more complete extinction in
the other hemisphere. We stress however, that such a pattern is likely only if the GRB
emission is isotropic and the event nearby. While at present we only see strong reasons for
associating a GRB with the Ordovician mass extinction, the entire fossil record bears 
examination in this light. Given the uncertainty in the evolution of the GRB rate, it is
possible that such events were involved in more than one mass extinction, or that more distant
GRBs could have a stochastic effect, providing small impulses to evolutionScalo & Wheeler, 2002).
A major challenge for astrophysics is to evaluate the likely flux and spectrum of cosmic rays
accompanying a burst.

Less than 10% of CO2 emmissions are due to mankind thus less than 10% of any residual effect of increasing CO2 is due to mankind:

Interesting way you put that. "Less than 10% of CO2 emissions are due to mankind." Perhaps that's true. However, why is atmospheric CO2 concentration increasing? You say (full exchange reproduced):

-----

cogitator: BECAUSE... you apparently alluded that the" increasing CO2 concentrations might be a climate effect, i.e., a response to a natural climate trend.

cogitator: You can easily say that a) is correct, and we can move on from there.

a) is incorrect as well as irrelevant due to lack of capacity to effect substantive change in earth's global temperature in comparison to the substantive affects of water vapor, and we can continue from there.

-----

for review, "a)" states: "a) the majority of CO2 added to the atmosphere since 1850 is from human sources, primarily fossil fuels"

OK. Let me state this right up front. If you say that a) is incorrect, you're wrong. Totally and completely wrong. I had to figure out where your wrongness is rooted before I can address all the other areas you've brought up. However, I'm prepared to fight out this line if it takes all winter.

There are several different lines of evidence that indicate that the increase in atmospheric CO2 commencing about 1850 ("dawn of the Industrial Age") is almost entirely anthropogenic. They are discussed on this Web page:

Why does atmospheric CO2 rise?

I will provide summary statements of each separate line of evidence for the anthropogenic cause of increasing atmospheric CO2. You can read about them in the Web page for further elucidation. (I've edited a bit for brevity.)

1. Ice cores show that during the past 1000 years until about the year 1800, atmospheric CO2 was fairly stable at levels between 270 and 290 ppmv. The 1994 value of 358 ppmv is higher than any CO2 level observed over the past 220,000 years.

2. The rise of atmospheric CO2 closely parallels the emissions history from fossil fuels and land use changes [Schimel 94, p 46-47].

3. The rise of airborne CO2 falls short of the human-made CO2 emissions. Taken together, the ocean and the terrestrial vegetation and soils must currently be a net sink of CO2 rather than a source [Melillo, p 454] [Schimel 94, p 47, 55] [Schimel 95, p 79] [Siegenthaler].

4. Most "new" CO2 comes from the Northern Hemisphere. Measurements in Antarctica show that Southern Hemisphere CO2 level lags behind by 1 to 2 years, which reflects the interhemispheric mixing time.

5. ** Important point provided in entirety.* Fossil fuels contain practically no carbon 14 (14C) and less carbon 13 (13C) than air. CO2 coming from fossil fuels should show up in the trends of 13C and 14C. Indeed, the observed isotopic trends fit CO2 emissions from fossil fuels. The trends are not compatible with a dominant CO2 source in the terrestrial biosphere or in the ocean. [On the Web page, details of this point are provided in the next two paragraphs.]

Reviewing, you said: "As a consequence of warming and release of watervapor with warming through variation of aldebo/reflection of solar flux, there is more biomass to produce CO2, greater release of CO2 from solution in oceans and glacial ices .... "

I have now shown that this statement is clearly wrong. The page demonstrates beyond scientific doubt that the cause of increasing atmospheric CO2 since about 1850 is predominantly anthropogenic, primarily from fossil fuel burning. Do you now concede that this point is correct?

I have now shown that this statement is clearly wrong.

You have shown nothing actually, as the same article makes it very clear that anthropogenic additions to the atmosphere are less than 5% of total additions to the atmosphere.

Emmissions cited in the article:

2.1 Natural carbon fluxes
                                                                     GtC / year
    Terrestrial vegetation --> atmosphere         60 Respiration
    Soils & detritus --> atmosphere                 60 Respiration
    Surface ocean --> atmosphere                   90
===================================================
Total natural carbon emmissions to atmosphere        210 GtC

2.2 Anthropogenic carbon
     Carbon dioxide sources                             GtC / year
      Fossil fuel burning, cement production               5.5 (5.0-6.0)
      Changes in tropical land use                              1.6 (0.6-2.6)
==================================================
Total anthropogenic emissions                            7.1 (6.0-8.2)

The page demonstrates beyond scientific doubt that the cause of increasing atmospheric CO2 since about 1850 is predominantly anthropogenic, primarily from fossil fuel burning.

Hardly:

Do you now concede that this point is correct?

No I do not, As I stated before, the earth cannot magically distinguish between Carbon from anthropogenic sources and Carbon from natural sources thus all carbon sinks must be taken in aggregate with respect to all sources of Atmospheric CO2 rather than attempting, as the article does, to separate "Anthropogenic" CO2 emmissions from "Natural" emmissions when evaluating Carbon sinks. You cannot take a "net" value of the Natural CO2, and then look at the whole value of Anthropogenic CO2 in evaluation of respective contributions.
Your point is based in a fallacy and without scientific foundation.

In fact, your point is indeed a mere strawman argument to boot to draw away from the essential factor,

Regardless of source of atmospheric CO2, the impact of changing CO2 concentration on the earth's Climate is nil:

As pointout in previous replies, and I will continue to point out:

CO2-Temperature Correlations

(1) correlation does not prove causation,
(2) cause must precede effect, and
(3) when attempting to evaluate claims of causal relationships between different parameters, it is important to have as much data as possible in order to weed out spurious correlations.

***

Consider, for example, the study of Fischer et al. (1999), who examined trends of atmospheric CO2 and air temperature derived from Antarctic ice core data that extended back in time a quarter of a million years. Over this extended period, the three most dramatic warming events experienced on earth were those associated with the terminations of the last three ice ages; and for each of these climatic transitions, earth's air temperature rose well in advance of any increase in atmospheric CO2. In fact, the air's CO2 content did not begin to rise until 400 to 1,000 years after the planet began to warm. Such findings have been corroborated by Mudelsee (2001), who examined the leads/lags of atmospheric CO2 concentration and air temperature over an even longer time period, finding that variations in atmospheric CO2 concentration lagged behind variations in air temperature by 1,300 to 5,000 years over the past 420,000 years."

[ see also: Indermuhle et al. (2000), Monnin et al. (2001), Yokoyama et al. (2000), Clark and Mix (2000) ]

"Other studies periodically demonstrate a complete uncoupling of CO2 and temperature "

[see: Petit et al. (1999), Staufer et al. (1998), Cheddadi et al., (1998), Raymo et al., 1998, Pagani et al. (1999), Pearson and Palmer (1999), Pearson and Palmer, (2000) ]

"Considered in their entirety, these several results present a truly chaotic picture with respect to any possible effect that variations in atmospheric CO2 concentration may have on global temperature. Clearly, atmospheric CO2 is not the all-important driver of global climate change the climate alarmists make it out to be."

Global warming and global dioxide emission and concentration:
a Granger causality analysis
http://isi-eh.usc.es/trabajos/122_41_fullpaper.pdf

"We find, in opposition to previous studies, that there is no evidence of Granger causality from global carbon dioxide emission to global surface temperature. Further, we could not find robust empirical evidence for the causal nexus from global carbon dioxide concentration to global surface temperature."

Here Comes the Sun

"Carbon dioxide, the main culprit in the alleged greenhouse-gas warming, is not a "driver" of climate change at all. Indeed, in earlier research Jan Veizer, of the University of Ottawa and one of the co-authors of the GSA Today article, established that rather than forcing climate change, CO2 levels actually lag behind climatic temperatures, suggesting that global warming may cause carbon dioxide rather than the other way around."
***
"Veizer and Shaviv's greatest contribution is their time scale. They have examined the relationship of cosmic rays, solar activity and CO2, and climate change going back through thousands of major and minor coolings and warmings. They found a strong -- very strong -- correlation between cosmic rays, solar activity and climate change, but almost none between carbon dioxide and global temperature increases."

Again we revisit the Geophysical record of CO2 and it's correlation to global temperture, this time we remove the catastrophic initiations of ice ages due to factors clearly not associated with CO2 concentration.

From the geological record, we can see a remainder trendline of CO2 concentration with respect to temperature by running a trend through the peak global tempertures.

As you have acknowleged the initiation of the deep iceages are clearly due to other factors such as plate tectonics, Gamma Ray Bursts, Meteoric events, etc.which initiate atmospheric cooling incident to the creation of high altitude cloud cover & icefields altering the mean albedo of the earth. Such effects lower overall irradiation of the earths surface and hence cools the surface. Under such conditions the major multi-million year iceages are induced. Remove their effects on the overall record, and what is left behind is a residual that can be perceived, to the first order, as a correlation of CO2 and temperature if we assume an essentially constant Solar radiation flux, which the IPCC modellers insist as being true.

I bring your attention to the two redline additions to our favorite chart:

The upper horizontal red line represents a peak temperature of 22.8^oC as represented at the chart Cambrian CO2 peak of 7000ppm. The second and descending redline is a rough approximation of the average peak temperatures which should be somewhat representative of any residual correlation between CO2 & temperature, we note that the downtrending redline terminates at approximately 21.6^oC and today's 320ppm CO2 concentration.

It should also be noted here that the relationship between CO2 radiant absorption capacity varies logrithmically with concentration of the gas under consideration in the atmosphere. For any fixed multiplier of change in concentration there is a linear incremental change in absorbed energy of the gas. Thus doubling, or halving, the concentration of CO2 will result in a linear increment in the absorbed radiation at the wavelengths CO2 is responsive to where incident radiative flux is constant.

7000ppm/320ppm = 21.9 (~ 4.45 doublings) with 22.8-21.6 = 1.2^oC change in temperature.

Overall atmospheric correlation between CO2 & increment of energy absorbed of necessity includes any temperature/concentration linkages that may actually occur in the atmosphere.

for 1.2^oC & 4.45 doublings, CO2 doubles for ~ 0.27^oC increase in global temperature

A value which is much less than the lowest 1.5to2.5^oC/doubling estimate built into the UN/IPCC global climate models, which suggests the relationship between CO2 and temperature built into the IPCC models is substantially overstated and in error.

The geophysical coefficient of doubling of CO2 concentration for each 0.27^oC increase in temperature, by the way, agrees well with many other means of computing the CO2 correlation.

A Lukewarm Greenhouse
"The average warming predicted by the six methods for a doubling of CO2, is only +0.2 degC."

You need to learn to stay on point. Posting huge amounts of unrelated information over and over again does not further the discussion. I will not respond to ten points at once.

You have shown nothing actually, as the same article makes it very clear that anthropogenic additions to the atmosphere are less than 5% of total additions to the atmosphere.

And they account for the fact that atmospheric CO2 concentrations are increasing, AG. You're either accidentally or deliberately overlooking the point that fossil fuel CO2 emissions can be distinguished from natural sources -- didn't you read the part about 14C and 13C isotopes? You say that the Earth cannot magically distinguish between natural and anthropogenic CO2 -- but scientists can. That's why one of the major efforts to examine the Earth's carbon cycle has been to determine the size of the sources and the sinks.

Here's a simple analogy. You have a bathtub. You have the faucet on and the drain is open. The bathtub is completely full, but because the amount coming in from the faucet is the exactly the same as the amount going down the drain, the level of the water in the bathtub does not change. Do you see that??? Now, you take a thimble and once a minute you add a thimbleful of water to the bathtub.

What is going to happen to the level of the water in the bathtub, AG? It doesn't matter if the rate of water being added from the faucet, or the rate of water going down the drain, are 100x greater than the rate of water being added to the bathtub from the thimble.

Fossil fuel sources of CO2 to the atmosphere account for the increasing concentration of CO2 in the atmosphere, even though they are not nearly as large as natural sources and sinks. They are a new (since the mid-1800s) source of CO2. And all of the evidence that can be brought to bear on this issue indicates that.

This is not a strawman, nor does it detract from what you think is the main issue. You have to admit that this point is true, because it is directly related to the contention that CO2 in the atmosphere is increasing for some other reason. There is only one reason, and that reason is well-known. Do you admit it, or not? (I'll get to all the other points you raise in due time. But this is point 1.)

You need to learn to stay on point.

I am precisely on point and continue to be, though you choose to try to make the issue other than: Change in CO2 concentration has nil effect on global climate.

This is not a strawman, nor does it detract from what you think is the main issue.

Definition of a straw man is simply the introduction of an irrelavant factor to bypass the central the issue. The issue is global temperature and its relation to CO2 concentration. Increasing levels of CO2 is a strawman as Earth's global temperature is only marginally effected by changing CO2 concentration. Where there is minimal causality and correlation it does matter what change in CO2 concentration is or what direction it is going.

You have to admit that this point is true, because it is directly related to the contention that CO2 in the atmosphere is increasing for some other reason.

I don't have to admit to any point regarding changing CO2 concentrations until such time as it can be shown that CO2 is the dominant factor regarding changes in Earth's global climate.

I especially do not have to admit or otherwise acknowledge irrelavent strawman arguments.

A 21 fold decrease across the last 500million years can only be correlated with a 1^oC decrease in global temperature.

I by no mean concede that changing "CO2" concentration has any substantive relevance to the issue at hand.

Fossil fuel sources of CO2 to the atmosphere account for the increasing concentration of CO2 in the atmosphere, even though they are not nearly as large as natural sources and sinks. They are a new (since the mid-1800s) source of CO2. And all of the evidence that can be brought to bear on this issue indicates that.

The issue is change in Earths average global temperature,

1) whether or not it is actually occuring,
2) if (1) is supported, then probable and significant causes global climate variation is of interest with CO2 somewhere near the bottom of the list of possibilities as a prime mover.

CO2 has been shown not to have an appreciable effect on Earth's average global temperature, this is true in a geophysical sense as shown from the information above as well as from other more direct measures as well:

A Lukewarm Greenhouse
"The average warming predicted by the six methods for a doubling of CO2, is only +0.2 degC.

The dominence of water vapor, icefields and high levels clouds are the significant factors in regard to the greenhouse effect as manifested on the earth, along with variation of incident visible light and gamma ray effects on the atmosphere.

Anthropogenic CO2 (e.g. fossil fuel burning) rising or not rising is a negligible factor of less than 0.12% of the total greenhouse effect on the Earth.

Anthropogenic (man-made) Contribution to the "Greenhouse
Effect," expressed as % of Total (water vapor INCLUDED)

Based on concentrations (ppb) adjusted for heat retention characteristics	% of All Greenhouse Gases	% Natural	% Man-made
Water vapor	95.000%	94.999%	0.001%
Carbon Dioxide (CO2)	3.618%	3.502%	0.117%
Methane (CH4)	0.360%	0.294%	0.066%
Nitrous Oxide (N2O)	0.950%	0.903%	0.047%
Misc. gases ( CFC's, etc.)	0.072%	0.025%	0.047%
Total	100.00%	99.72	0.28%

Until you are prepared to accept the marginality of the role of CO2 in the Earth's atmosphere in regard to changing climate, you and I really have no basis on which to discuss this matter.

Atmospheric CO2 concentration is simply not a substantive causitive factor in changing Earth's climate.

I am precisely on point and continue to be, though you choose to try to make the issue other than: Change in CO2 concentration has nil effect on global climate.

That's your central contention; I'm aware of that. However, to address it we have to address the Earth's entire climate system. The indication that you thought/think that the currently increasing atmospheric CO2 concentrations are a climate effect (rather than having a primarily anthropogenic cause) tells me that you have only a minimal understanding of Earth's climate system. I would like to introduce into this discussion a couple of papers by Berner (one very recent one) that are utterly at odds with your stated contention above. However, in order to do that I first have to be convinced that you comprehend the basics of what's happening now. And one of the basic things that's happening now is increasing atmospheric CO2 concentrations due to energy production and land use changes. I will state that now as a postulate, so that we can move on to the next phase of the discussion. In essence, I'm going to have to ignore your intractability and take it as a sign of advancing senility. I'll do my best to work around it.

The issue is global temperature and its relation to CO2 concentration.

Precisely why it's important to know what is happening with atmospheric CO2 concentrations and why.

Increasing levels of CO2 is a strawman as Earth's global temperature is only marginally effected by changing CO2 concentration.

Not according to Dr. Berner. Here's a lead quotation from one of the papers I wish to introduce:

"Over Phanerozoic time a major control on global climate has been the CO2 greenhouse effect, and changes in CO2 have been a consequence of a combination of geological, biological, and astronomical factors."

That's totally at odds with your contention, AG. And you're an anonymous name to me. Dr. Berner is:

Robert A. Berner

Alan M. Bateman Professor of Geology and Geophysics (Yale University)

Member of National Academy of Sciences
Doctor Honoris Causa, Universite Aix-Marseille (France), 1991
Huntsman Medal in Oceanography (Canada), 1993
Goldschmidt Medal (Geochemical Society), 1995
Arthur L. Day Medal (Geological Society of America), 1996
Murchinson Medal (Geological Society-London), 1996

Lest you contend that this is an argument from authority, it's not. I am attempting to bring the published research statements of one of the most noted geochemists in the United States (and the world) into this discussion. And he basically says that your contention is wrong; that CO2 is a major climate factor.

I don't have to admit to any point regarding changing CO2 concentrations until such time as it can be shown that CO2 is the dominant factor regarding changes in Earth's global climate.

OK, then Dr. Berner's statement has been introduced into this discussion as a counterpoint to yours. Therefore, I state that is now relevant for you to admit the cause of increasing atmospheric CO2 concentrations, because Dr. Robert Berner states that the CO2 greenhouse effect is a major control on global climate over Phanerozoic time.

The issue is change in Earths average global temperature,

1) whether or not it is actually occuring,

Global temperatures are currently rising.

2) if (1) is supported, then probable and significant causes global climate variation is of interest with CO2 somewhere near the bottom of the list of possibilities as a prime mover.

Reread the statement by Dr. Berner that has been introduced into the discussion.

CO2 has been shown not to have an appreciable effect on Earth's average global temperature, this is true in a geophysical sense as shown from the information above as well as from other more direct measures as well:

Your statement above is at odds with Dr. Berner's statement.

Interesting that you should bring up icefields. So does Dr. Berner when discussing Dr. Veizer's research results, of which you are so fond. Dr. Berner does not find them nearly so compelling.

Until you are prepared to accept the marginality of the role of CO2 in the Earth's atmosphere in regard to changing climate, you and I really have no basis on which to discuss this matter.

It's hard to dislodge a tree whose roots have grown so deep, AG. However, the statements of the esteemed Dr. Berner indicate that your contention regarding the marginality of atmospheric CO2 concentrations on Earth's climate is incorrect. Until such time as you allow discussion so that you can demonstrate why and how Dr. Berner is incorrect, I will accept his statement over your contention (particularly since it is so hard for you to admit a simple statement of fact, that the rise in atmospheric CO2 concentrations occurring since the mid-1800s is due to fossil fuel burning and land-use changes).

I don't care if you decline to continue this discussion. But if I comment on a global warming thread, or if I see your commentary, my next step will be to introduce Dr. Crowley and Dr. Berner's recently published paper regarding CO2 and climate change. I'm being eminently fair here; now you can look up this reference and see what I'm talking about. Or we can continue on this thread.

What do you want to do next, AG?

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