A COMPELLING WAY OF VIEWING human progress, of equal appeal to those with roots in 19th century liberalism and those inclined to Marx's "scientific" socialism, is to see it as a triumphal march toward a purely hydrogen energy economy--or, if you prefer, a carbon-free economy. This is just how a collection of scholars looked at the world when they were assembled a few years ago by the American Academy of Arts and Sciences to produce a special issue of Daedalus magazine on the global environment.
Setting the stage for the special issue, its editor Jesse Ausubel, director of the program for the human environment at Rockefeller University in New York City, reminded readers that it is the conversion of hydrogen in hydrocarbon fuels that accounts for most of their energy yield. Since hydrogen produces about four times as much energy per quantity H oxidized as per unit C, wrote Ausubel, "Wood weighs in heavily [with] ten effective Cs for each H. Coal approaches parity with one or two Cs per H, while oil improves to two H per C, and a molecule of natural gas (methane) is a carbon-trim CH 4 ."
From this perspective, in a utopian carbon-free future, all energy might come from some combination of fission, fusion, and fuel cells. And nowadays, the advanced industrial economies, relying mainly on natural gas, can be seen as traversing their carbon-trim phase on the way to that goal. But countries like China and India are struggling at a stage in some ways akin to the worst and least efficient phases of Europe's Industrial Revolution, two centuries back. To a remarkable extent, the peasants and farmers who make up most of their huge populations rely on biomass (woody matter, dung, and crop residues) for their fuel, while their modernizing industrial sectors run on coal.
Almost entirely because of that dependence on coal and biomass, China and India together contribute nearly one-fifth of the carbon dioxide the human race pumps into the atmosphere yearly. And since CO 2 is by far the most important greenhouse gas thought to be warming the world, China and India already are a major ingredient in climate-change scenarios. If China continues to grow at the remarkable rates registered since 1980, it will surpass the United States as the leading source of CO 2 emissions by the middle of the next century. And should India enter into a similar take-off phase of breakneck economic growth, it will not be far behind.
So, if countries like the United States want to mitigate risks of climate change, after cleaning up for themselves and getting their own houses in order, the next-best thing they can do is help China and India do the same.
This, then, is the subject of IEEE Spectrum 's special report: what can China and India realistically hope to do in the next two or three decades to reduce reliance on coal and get on the road to decarbonization, whether by burning coal more cleanly and efficiently or by adopting alternative energy technologies? And what can the advanced industrial countries do to help?
Why should anyone care?
After water, the carbon released in the production and use of energy is the largest mass flow connected with human activity. Annual carbon emissions are estimated at 6 billion tons, or roughly 1 ton per person on earth. To be sure, the ratio of carbon used to energy produced has improved by 40 percent since the middle of the last century, representing an average decline of about 0.3 percent per year. But because of both economic and demographic growth, the total amount of carbon emitted into the atmosphere has gone on increasing and at present rates would roughly double in the next 40 or 50 years.
Why should this matter? Surely the relationship between carbon dioxide emissions and climate is highly speculative? Aren't the temperature records and climate models on which projections are based full of ambiguities and holes? For every scientist who thinks people are making the world warmer, is there not another who believes the opposite?
The short answer to all those questions is No. Scientists who flatly disbelieve human activity is warming the world are a tiny minority among those studying the subject. The link between changes in levels of greenhouse gases (GHG) and climate change is firmly established. And temperature records and climate models are becoming more precise with every passing year.
In 1995, the Intergovernmental Panel on Climate Change (IPCC) reported for the first time that a human fingerprint could be detected in the world's persistent warming trend. The IPCC is a global network of scientists set up under United Nations auspices in 1988 to provide authoritative assessments of knowledge as it evolves. The panel concluded that "the balance of evidence suggests a discernible human influence on global climate."
Since 1995, the evidence has mounted that the world is heating up alarmingly, and that such changes in the world's climate correlate closely with concentrations of carbon dioxide in the atmosphere. Accelerated melting of glaciers and ice sheets in the Arctic, Greenland, and Antarctica, changes in wildlife habitats reported from many parts of the earth, weather irregularities consistent with predictions from the best climate models--all this and more are omens of difficulties to come. Hanging in the balance: patterns of agricultural productivity, sea levels and coastal economic systems, forests, and species.
A 1000-year record
The most direct evidence of climate change comes from the climate record itself and from paleohistorical studies of greenhouse gas concentrations.
A team at the University of Massachu-setts, in Amherst, is generally considered the world's most expert group on the earth's intermediate-term temperature record--the last millennium, that is. Last March, it reported that the warming experienced this century runs counter to a very gradual cooling trend seen throughout the previous 900 years. Before the 20th century, the Massachusetts researchers found, the earth was cooling by about 0.02 degree kelvin each century; but in just one century it has now warmed by nearly a degree kelvin.
The Massachusetts study confirmed findings from other teams that the 1990s have been warmer than any decade of the last century, with nearly every year outdoing the last one. But the Massachusetts group also went further, affirming that the earth is now warmer than it has ever been in the last millennium, including even a noted balmy spell experienced by Europe in the Middle Ages. Still, the suddenness and sharpness of this century's reversal in trend are what worry the team the most. "If temperatures change slowly, society and the environment have time to adjust," said Michael Mann, a member of the Massachusetts team now at the University of Virginia, Charlottesville. "The slow, moderate, long-term cooling trend that we found makes the abrupt warming of the late 20th century even more dramatic" [Fig. 2].
 A 900-year cooling trend has reversed in the last century.
The Massachusetts study was based on data from tree rings in Scandinavia, Russia, Tasmania, Argentina, Morocco, and France, as well as North America, plus ice cores from holes drilled deep in the ice of Greenland and the Andes. In addition, Mann told Spectrum , the team drew on information of the kind used by historians, including anecdotal evidence and documentary records from Europe and Asia. The all-India monsoon record going well back into the 19th century proved useful, as did records from Japan and China on harvests, floods, and freezes.
"Suddenly," said Mann, "we're seeing warmth at the global or hemispheric scale that hasn't been exhibited by the climate in 1000 years and probably longer. The warming of the 20th century is outside the envelope of that longer time frame. And there are no variations at the decadal or century time scales that are as sharp and rapid as the warming of the 20th century, or that led to a regime anywhere near as warm."
Uncertainties not to be minimized
Needless to say, the farther back into climate history the probing extends, the more guesswork is involved. Assumptions have to be made about how data originated, what feedback mechanisms were at work, whether complexly coupled systems worked essentially the same way as today or not, and so on.
Phil Jones, a professor at the University of East Anglia, in Norwich, England, has commented that the Massachusetts work, precise and careful as it may be, still has to rely on a lot of assumptions as soon as it parts way with actual instrument readings. Widely considered the world's leading expert on the instrumental temperature records, which go back into the 19th century, Jones emphasizes the need for still more work.
Mann in turn told Spectrum that when one goes deeper into prehistory than his colleagues have gone, where researchers have to rely entirely on data from ice cores and ocean-floor borings, with little collaborative evidence except for the geological record, the assumptions naturally get even more heroic.
An argument often propounded by political economists of a conservative cast of mind urges that in the absence of perfect knowledge, it is better not to act at all than to act in haste, which can lead to unintended consequences and may possibly make things worse rather than better. Naturally enormous uncertainties and unknowns in climate science can be mustered to support such arguments.
The actions and reactions of the earth's cloud cover, which both reflects and captures solar energy, is one subject of ongoing empirical and theoretical study. Another top research subject is the character of ocean-atmosphere coupling (exchanges of heat and moisture between the oceanic and atmospheric systems). Until very recently, all the major climate models required a "flux correction factor" to be built in, to fudge that. Yet another uncertainty concerns the magnitude and nature of the world's carbon sinks, a dilemma highlighted by the failure of many models to account for all the carbon thought to be entering the atmosphere.
The skeptic's argument probably arousing the most public controversy, at least of late, concerns the impact of sunspot cycles. It has been ably articulated by Sally Baliunas, an astrophysicist currently working as chief scientist at the George C. Marshall Institute, in Washington, D.C., and deputy director of the Mount Wilson Observatory, outside Pasadena, Calif. Writing in The Wall Street Journal on 5 August, Baliunas said: "Changes in the length of the [solar] magnetic cycle and in Northern Hemisphere land temperatures are closely correlated over three centuries....Those changes in the sun's magnetism would track changes in the sun's brightness, for which direct measurements are lacking. If this is so, changes in the sunspot cycle would explain the average temperature change of about 0.5 degree Celsius in the past 100 years."
In a rebuttal submitted to the Journal , the University of Virginia's Mann said: "Recent studies, including our own, suggest that solar influences may have played a part in some of the warming during the period from roughly 1850 to 1950....The very same studies quite clearly indicate, however, that neither variations in solar output, nor volcanic influences, can account for the magnitude of the observed 20th century warming, especially the dramatic warming since the late 1970s."
The biggest-ever increase in CO 2
So vast are the uncertainties in the science (or art) of climate modeling that many key issues will not be resolved for decades to come, if then. Some crucial facts, however, are largely agreed upon. The earth's temperatures and the amounts of greenhouse gases in the atmosphere are precisely measurable quantities, and both are steeply higher than in previous epochs. Further, the general factors driving climate change in aeons past are not much in dispute, even if the details are controversial in the extreme.
The general consensus among climate modelers, paleoclimatologists, and climate historians is that most climate change during the Ice Age cycles of the last two million years was driven by astronomical variables. Specifically, changes in the earth's orbital parameters--eccentricity, obliquity, and precession of axis--are what led to variations in the intensity and distribution of sunlight. These in turn caused carbon dioxide and methane levels to change, mainly because of effects from biological systems, whereupon the modified concentrations of those gases amplified temperature changes.
Taking the known uncertainties into account and employing methods of almost mind-numbing complexity, a large international team reported last June that they had pushed the climate record back 420 000 years. Relying mostly on ice cores from a drilling station at Vostok in East Antarctica, they compared climate variation and changes in atmospheric chemistry through the past four cycles from ice age to warm period and back. Their main finding, reported in Nature magazine, was that levels of carbon dioxide and methane correlated well throughout the period with air temperatures, and that present levels of the two greenhouse gases are very much higher than at any other time during the last 420 millennia. Specifically, during all four glacial-to-interglacial transitions, concentrations of carbon dioxide climbed from 180 parts or so per million to about 280300 ppm. Since preindustrial times, the level has risen from 280 ppm to about 360 ppm [Fig. 3].
 A 420 000-year climate record [above] shows carbon dioxide, methane, and temperature levels changing in lockstep. It is based mainly on ice core samples from Antarctica [near right].
In other words, best estimates indicate the level is now much higher than it has been at any time since the beginning of the ice ages.
Better safe than sorry?
Given the evident dangers of failing to act on global warming warnings until it is too late, the world community has chosen to take the IPCC at its word and use its reports as a basis for concerted action. The panel's first global assessment, in 1990, laid the foundation for the 1992 Framework Convention on Climate Change, which established a procedure for continuing negotiation and reporting by 170 member states. Similarly, the 1995 IPCC report identifying the human fingerprint provided the basis for the 1997 Kyoto Protocol. This pact set emission-reduction targets for the industrial countries, allowed countries to meet targets partly by trading "emission credits," and provided mechanisms for the richer countries to help the less advanced minimize growth in emissions.
In follow-on meetings, every major aspect of the Kyoto Protocol has remained enormously contentious. Europe and the United States are split on how fast emissions can be reduced and how much allowance should be made for emissions trading--allowing countries that have surpassed reduction targets to trade credits with those failing to meet them. The developing countries are loath to admit global warming into their economic development plans. Yet the precautionary principle enshrined in the Kyoto Protocol--the common-sense proposition that when it comes to the global environment, it is better to be safe than sorry--seems here to stay.
The Kyoto targets were an average reduction by 200812 in comparison with the 1990 level of 5.2 percent for the world as a whole, 6 percent for the United States. When they were adopted, critics were quick to denounce them as too ambitious. The U.S. target was tantamount to a real cut of 30 percent, if projected growth in U.S. emissions under business-as-usual scenarios were reckoned in, argued Vito Sagliano in Elsevier's Electricity Journal. Sagliano is a former deputy assistant energy secretary for policy analysis in the U.S. Department of Energy.
A chairman of the U.S. President's Coun-cil of Economic Advisers said that Kyoto implementation might add $70$110 to the average U.S. resident's yearly energy bill.
Because of such concerns, the Clinton administration proposed measures that emphasized energy research but eschewed the carbon or energy taxes adopted by a few European countries (sometimes with tax-credit offsets, to make them fiscally neutral). Soon, though, an analysis by the U.S. Department of Energy's Energy Information Administration (EIA) found that little in the way of concrete results could be expected from the measures proposed.
Happily, the latest data on U.S. and global emissions suggests that it may be less difficult and costly to reduce GHG emissions than first supposed. The EIA reported this summer that U.S. emissions stayed flat last year, despite robust economic growth. Independently, Christopher Flavin of Worldwatch Institute in Washington, D.C., used data from the oil company BP Amoco PLC to calculate that global emissions dropped 0.5 percent in 1998 while the world economy grew 2.5 percent. Astonishingly, China's emissions fell almost 4 percent, even as its economic growth passed 7 percent.
The role of China and India
During China's economic reform period, now nearly two decades old, there has been a steady decline in the amount of energy it needs to produce a unit of output. According to the World Bank, this energy intensity has shrunk by close to 50 percent. India's energy intensity, in contrast, has continued to increase somewhat in recent decades, suggesting it might have something to learn from its neighbor. At the same time, India has pioneered some alternatives to coal--wind energy, for example --where China might have something to learn.
Any efforts at cooperation naturally must reckon with the glaring cultural, social, and political differences that separate the two neighbors. Equally important are differences in the resources the two countries can deploy in campaigns to improve their energy sectors, including human resources.
Although drinking water is comparable in quality in each country, the general level of public sanitation, health, and education is vastly superior in China. Partly because of that, no doubt, China's economy has been growing for nearly 20 years at rates mostly in the vicinity of 10 percent a year, a truly striking take-off into industrialization. Granted, India's economy also has been growing quite smartly in recent years. But it has yet to match China's amazing performance.
The economic contrast between the two great countries is underscored by their balance of international payments. China's exports and imports each are approaching US $200 billion per year, and at last definitive reckoning (1998), its foreign currency reserves came to a whopping $150 billion. India's exports in 1998 were $33 billion and imports $43 billion; its reserves are just over $30 billion. China, in a nutshell, has a lot more disposable cash to spend on new technology. Moreover, foreign direct investment in China came to more than $44 billion in 1996, 13 times as much as went to India that year.
Yet here, too, in the realm of political and economic prognostication, uncertainties are enormous. When one reads that China's economy will keep growing at current rates, so that in 2025 total demand for electricity and emissions of greenhouse gases will be three or four times as high as now, the first thing to say is maybe . In some ways, China's economic performance resembles the boom-bust cycles seen in the industrial countries during the late 19th century. Not to be left out of the reckoning, either, are fundamental political indeterminates.
Looking at China from the outside, it is tempting to compare its political leaders with the non-ideological technocrats who governed in countries like Spain during an authoritarian transition from dictatorship to democracy. But that is not how the Chinese leaders see themselves. What they view themselves as doing, argues Maurice Meisner, author of a recent book on the Deng Xiaoping era, is building the capitalist foundation that according to Marx is the precondition for true socialism. In essence, they consider themselves much more orthodox Marxists than Mao himself, argues Meisner, a China scholar at the University of Wisconsin, Madison.
India may also have surprises in store. Just a year ago, when Spectrum began the groundwork for this special report, the subcontinent seemed to be coming apart politically. At the beginning of the decade, the eminent writer V.S. Naipaul had just published a major survey of the country subtitled A Million Mutinies Now. What he meant was that the country was dissolving into ever more finely grained sectarian strife. Nothing in the next nine and a half years seemed to prove him wrong. Yet in just the past few months the new Hindu-nationalist government has skillfully consolidated its position--not without cynically exploiting foreign conflicts and domestic xenophobia, let it be said--and has just registered a major electoral victory.
So, while scientists may be able to state the typical relationship between greenhouse gases and world temperatures on a scale of millennia or hundreds of millennia, only a fool would claim to know what a country like China or India will look like a decade from now.
The special report
In considering China and India, it should be borne in mind that both are still heavily agricultural, and that not all greenhouse gases are due to industrialization or even energy. Rice paddies and ruminant livestock are a significant source of methane, a more potent greenhouse gas than carbon dioxide. Thus, in China, according to the most authoritative study yet of GHG emissions, over half of current and projected methane emissions stem from agriculture. A similar study of India found that agriculture (excluding burning of biomass) at present accounts for about one-third of total GHG emissions.
Also to be recalled: while the general global effects of GHG emissions can be stated with some confidence, estimates of near-term regional impacts are far more fraught with error and uncertainty. In particular, the sulfate aerosols closely associated with coal combustion mask rather than enhance the greenhouse effects, so that the immediate effects of burning coal can be to make local climates cooler rather than warmer. Thus, there are dangers in implying that China and India will suffer immediately if they do not take action on GHG abatement, or will benefit right away from actions taken.
That said, in both China and India energy conversion is by far the most important single source of greenhouse gases, and from a global perspective, it is one of the most important factors influencing the world's long-term climate. And within their energy profiles, the power sectors are the largest and most readily analyzed item.
Therefore, the following articles provide overviews of the energy economies in China and India and point to some key issues that will have to be addressed if dependence on coal is to be reduced. The objective is to assess how much potential there is for burning coal more cleanly and efficiently, and how much potential there is for substituting other energy technologies for coal.
The first two articles are coauthored by Marlowe Hood, a China specialist and journalist based in France, who spent three weeks in China. The same job was done in India by Vir Singh, an Indian journalist based in Delhi.
A second package of articles in the December issue will discuss some key changes that will be required to improve energy efficiency in China and India and help them join the advanced industrial countries on a path to carbon-free energy. Topics to be discussed will include energy pricing, air pollution abatement, and the application of new technology to achieve efficiencies in energy use.
To Probe Further
A special issue of the magazine Daedalus , "The Liberation of the Environment," was published in summer 1996 and republished in book form by the National Academy Press, Washington, D.C.
Expected impacts of climate change, not discussed here, may be explored on the World Wide Web site maintained by Britain's Hadley Centre for Climate Prediction and Research, Bracknell, Berkshire. Co-located with England's Meteorological Office, it does much of the work on this subject for negotiators from the Intergovernmental Panel on Climate Change (IPCC), in Geneva. The Web address is: http://www.meto.govt.uk/sec5/CR_div/Brochure98/findings.html.
The major climate models are created and maintained by the National Center for Atmospheric Research, Boulder; the Princeton Fluid Dynamics Laboratory; the Max Planck Institute for Meteorology, Hamburg; and the Hadley Centre. The Hamburg model may be accessed through a Web site maintained by four German institutions: http://www.dkrz.de. Information on the Hadley Centre's model can be accessed at the British Meteorological Office's Web site, above. For Boulder's model, go to http://www.ncar.ucar.edu/; and for Princeton's, http://www.gfdl.gov. The Intergovernmental Panel on Climate Change (IPCC) can be accessed by e-mail at
The most recent work on the 1000-year temperature record by Michael Mann, et al., appeared in the 15 March 15 of Geophysical Research Letters . Background information about it, including reactions from other scholars, may be found on the Web at http://www.umass.edu/newsoffice/press/98/0422cli.html. The report on the 420 000-year record by J.R. Petit, et al., appeared in Nature , 3 June 1999, pp. 42935. Leads and lags in that record were explored by H. Fisher, et al., in Science , 12 March 1999, pp. 171214.
Articles in the 16 October 1998 issue of Science by Oliver L. Phillip, et al. (pp. 43942) and by S. Fan, et al. (pp. 442449), suggested that much larger carbon sinks might exist in both tropical forests and in North America. Those results were noted in The Electricity Journal , December 1998, p. 15. The same journal has publicized Baliunas' views about the sunspot cycle (October 1998, pp. 1112) and published a provocative critique of the Kyoto accord by Vita Stagliano (October 1998, pp. 7173).
The role of public health and education in economic performance is discussed by economist and Nobelist Amartya Sen in Development as Freedom (Knopf, New York, 1999). Maurice Meisner's book is The Deng Xiaoping Era (Hill & Wang, New York, 1996).
The two major greenhouse gas reports are: India: National Report on Asia Least-Cost Greenhouse Gas Abatement Strategy , Ministry of Environment and Forests, New Delhi, June 1998; and China Climate Change Country Study , U.S. Department of Energy and the State Science & Technology Commission of China (Tsinghua University Press, Beijing, 1999).