Slowing global warming.

SLOWING GLOBAL WARMING

Global warming promises to be one of the central environmental issues of the '90s. After a decade of scientific concern but popular neglect, the '80s ended with a growing political and scientific consensus that the world can no longer afford to procrastinate about this issue. Plans call for the drafting of an international climate treaty in 1990, and for its formal adoption at a global environmental summit in 1992.

This action can hardly come too soon. Changes to the earth's atmosphere are by nature global and - for all practical purposes - irreversible, not only in our lifetimes but in those of our children and grandchildren as well. Lending urgency to the problem is the fact that the chemical composition of the earth's atmosphere is already quite different than it was just a century and a half ago. We have already committed ourselves to more climate change than many societies will be able to cope with.

Nitrogen and oxygen are still the main constituents of the atmosphere, but several more complex gases are building steadily: carbon dioxide ([CO.sub.2]) is up 25 percent, nitrous oxide 19 percent, and methane 100 percent. Chlorofluorocarbons (CFCs), a class of synthetic chemicals not normally found in the atmosphere, have added further to this blanket of gases that allow sunlight in but trap the resulting heat.

Global average temperatures are now about 0.6 degrees Celsius warmer than they were 100 years ago. No conclusive proof links this recent heating to the greenhouse effect, but circumstantial evidence has convinced many scientists that this is the cause. Of more concern, however, is the much faster warming that is predicted by a half-dozen computer models - reaching an increase of 2.5 to 5.5 degrees Celsius late in the next century. The difference between the warming of the past century and that expected in the decades ahead is like that between a mild day in April and a late-summer scorcher.

Although climate change is a young science, many aspects of which are uncertain, this is no excuse for delay. Societies invest in many programs, such as defense, to protect against an uncertain but potentially disastrous threat. Similarly, investing in strategies to slow global warming is a sort of insurance policy - against catastrophes that have far greater odds of occurring than do most events for which we buy insurance. And many of these programs are economical investments in their own right, cutting energy bills and air pollution as well as helping to restore the carbon balance.

Coping effectively with global warming will force societies to move rapidly into uncharted terrain, reversing powerful trends that have dominated the industrial age. This challenge cannot be met without a strong commitment by both individual consumers and governments. In terms of the earth's carbon balance, the unprecedented policy changes that have now become urgent include a new commitment to greater energy efficiency and renewable energy sources, a "carbon tax" on fossil fuels, a reversal of deforestation in tropical countries, and the rapid elimination of CFCs.

The Global Carbon Budget

The element carbon has become one of the largest waste products of modern industrial civilization. During 1988, some 5.66 billion tons were produced by the combustion of fossil fuels - more than a ton for each human being. Another one to two billion tons were released by the felling and burning of forests, mainly in tropical areas. Each ton of carbon emitted into the air results in 3.7 tons of carbon dioxide, the seemingly innocuous gas that is now one of the principal threats to humanity's future.

Global carbon emissions have grown rapidly during the postwar period. It took 10 years for them to go from two billion to three billion tons, but just six more years to get up to four billion. This trend has of course been fueled by other exponential growth rates - namely of population and economic output, which translated into ever-greater use of fossil fuels. Increases in oil use have been particularly rapid, but during the '80s the use of coal and gas has also swelled.

The past four decades of growth can be broken into three distinct periods. (See Figure 1.) From 1950 to 1973, the annual increase in carbon emissions was a remarkably steady 4.5 percent; from 1973 to 1983, emissions gyrated wildly but on average increased at a yearly rate of just 1.0 percent; since then, more rapid growth has resumed, at an average rate of 2.8 percent a year. In 1988, carbon emissions went up 3.7 percent, the largest annual increase in almost a decade.

If expansion had continued at the pre-1973 rate, annual emissions today would be almost three billion tons higher. Of course, the slowdown was not the result of actions to protect the atmosphere. It stemmed from the effects of the two oil crises, energy-policy changes in some countries, and global economic problems that have hit developing countries severely.

More than one-third of the drop in the carbon-emissions growth rate since 1973 can be traced to the declining energy intensity of many countries, although a large disparity in percapita carbon emissions still exists even among industrial market countries (see Table 1). The impact of improved energy efficiency would have been even greater except for the fact that the efficiency revolution largely bypassed other parts of the world. Rising use of renewable energy and nuclear power played a significant but smaller role since 1973, offsetting some 500 million tons of annual emissions.

Table : Table 1. Carbon Emissions from Fossil Fuels, Selected Countries, 1960 and 1987

                                  CARBON PER    CARBON PER
                    CARBON        DOLLAR GNP       CAPITA
COUNTRY          1960    1987    1960   1987    1960   1987
                 (million tons)     (grams)        (tons)
United States    791     1,224   420    276     4.38   5.03
Canada            52       110   373    247     2.89   4.24
Australia         24        65   334    320     2.33   4.00
Soviet Union     396     1,035   416    436     1.85   3.68
Saudi Arabia       1        45    41    565     0.18   3.60
Poland            55       128   470    492     1.86   3.38
West Germany     149       182   410    223     2.68   2.98
United Kingdom   161       156   430    224     3.05   2.73
Japan             64       251   219    156     0.69   2.12
Italy             30       102   118    147     0.60   1.78
France            75        95   290    133     1.64   1.70
South Korea        3        44   274    374     0.14   1.14
Mexico            15        80   446    609     0.39   0.96
China            215       594     -  2,024     0.33   0.56
Egypt              4        21   688    801     0.17   0.41
Brazil            13        53   228    170     0.17   0.38
India             33       151   388    655     0.08   0.19
Indonesia          6        28   337    403     0.06   0.16
Zaire              1         1     -    183     0.04   0.03
  World        2,547     5,599   411    327     0.82   1.08

SOURCE: Worldwatch Institute, based on Gregg Marland et al., Estimates of [CO.sub.2] Emissions from Fossil Fuel Burning and Cement Manufacturing, Based on the United Nations Energy Statistics and the U.S. Bureau of Mines Cement Manufacturing Data (Oak Ridge, Tenn.: Oak Ridge National Laboratory (ORNL), 1989); Gregg Marland, ORNL, private communication, July 6, 1989; Economic Research Service, World Population by Country and Region, 1950-86, and Projections to 2050 (Washington, D.C.: U.S. Department of Agriculture, 1988); U.S. Central Intelligence Agency, Handbook of Economic Statistics, 1988 (Washington, D.C: 1988); World Bank, World Development Report 1989 (New York: Oxford University Press, 1989).

In Eastern Europe and the Soviet Union, where most industries and individuals are shielded from market incentives, energy intensities have remained essentially unchanged, and efficiency in most sectors is only about half that in Western Europe. Thus, although Soviet per-capita economic output (measured in purchasing power) is only two-thirds that of Western Europe, per-capita carbon emissions are almost twice as high. Though economic restructuring is intended to improve energy efficiency and thus reduce carbon emissions, a Soviet society with automobiles and larger houses could push carbon emissions beyond the current level.

The Third World currently burns fossil fuels at far lower rates than the industrial world. With many people continuing to live in poverty in the countryside, fossil fuels are often too expensive or simply unavailable. In many of these countries, a sizable portion of energy needs is met through the combustion of wood, straw, and other biomass fuels, which despite their importance are not generally counted in energy statistics. Yet burning these fuels also emits carbon, and when they are not replaced by new trees or other plants, the atmosphere receives an additional burden.

Many developing countries are adding far more carbon to the atmosphere through deforestation than through fossil-fuel combustion. Brazil, for example, contributes some 336 million tons of carbon each year through deforestation, over six times as much as through burning fossil fuels (see Table 2). Combining these two sources makes Brazil the fourth largest carbon emitter in the world. Deforestation also pushes Indonesia and Colombia into the top 10 global emitters.

Table : Table 2. Estimated Carbon Emissions from Deforestation and Fossil Fuels in Selected Countries

                DEFORESTATION,             FOSSIL FUELS,     TOTAL
COUNTRY              1980                       1987         TOTAL
                          (million tons)
Brazil               336                        53           389
Indonesia            192                        28           220
Colombia             123                        14           137
Thailand              95                        16           111
Cote d'Ivoire        101                         1           102
Laos                  85         [is less than ] 1            85
Nigeria               60                         9            69
Philippines           57                        10            67
Malaysia              50                        11            61
Burma                 51                         2            53
Others(1)            509                       181           690
  Total(1)         1,659                       325         1,984

(1)65 countries. SOURCES: R.A. Houghton et al., "The Flux of Carbon from Terrestrial Ecosystems to the Atmosphere in 1980 Due to Changes in land Uses: Geographic Distribution of the Global Flux,"Tellus, February-April 1987; Gregg Marland, Oak Ridge National Laboratory, private communication, July 6, 1989.

Although considerable uncertainty remains about the precise rate of deforestation, strong circumstantial evidence indicates it is accelerating. Tropical countries report ever more rapid losses of forests, and satellite reconnaissance confirms this. As with fossil-fuel use, this suggests a challenge ahead. It is one thing to accomplish a goal from a standing start. It is quite another to turn around an ongoing and powerful trend.

The U.S. Environmental Protection Agency has estimated that to stabilize atmospheric concentrations of CO2 at the current level, carbon emissions must be cut by 50 to 80 percent, taking them back to the level of the '50s. Policymakers meeting in Toronto in June 1988 offered a short-term goal: cutting them by 20 percent by 2005.

Even a 20-percent cut in carbon emissions would mark a dramatic shift in direction and require wholesale changes in energy policy and land-use patterns around the world. Such goals, though feasible, will force policymakers to consider familiar issues in a dramatically different context. In the past, international emissions of carbon were left to the marketplace. But markets by nature ignore environmental costs. Continuing with business as usual will result in a rapid undermining of the habitability of the planet during the next 20 to 30 years.

Any realistic strategy must start with the fact that one-fourth of the world's population accounts for nearly 70 percent of the fossil-fuel-based carbon emissions. This wealthy, energy-intensive quarter has an obvious responsibility to lead in the search for solutions. But the level of carbon emissions in developing countries remains an extraordinarily difficult issue. It is a simple fact of science that the planet will never be able to support a population of eight billion people generating carbon emissions at the rate, say, of Western Europe today.

The implied growth to just more than 16 billion tons of carbon emissions per year during the next few decades would result in a concentration of [CO.sub.2] that is perhaps three times the preindustrial level - well above even the doomsday scenarios developed by climate modelers. But even continuing along the current path would not leave the world in much better shape. At the recent annual growth rate of about three percent, carbon emissions in the year 2010 would reach nearly twice the current level, and by 2025 would be three times where we are today. And since other greenhouse gases are rising in concentration as well, the amount of warming would be well above that projected from carbon dioxide alone.

A frighteningly large gap looms between projected growth rates in carbon emissions and the level that atmospheric scientists believe is necessary to maintain a climate that can meet human needs. World leaders meeting at the Hague environmental summit in March 1989 and the Paris economic summit in July 1989 agreed on a need to cut carbon emissions. But no one has begun to wrestle with the crucial equity issues this need raises.

How much of a burden should the United States, as a wealthy and energy-intensive country, have to bear? And what about Japan, which is frugal in its consumption of fossil fuels but is one of the few nations with capital surpluses? Should the use of fossil fuels be constrained in developing countries or should most of their effort be devoted to reversing deforestation? And what of the Soviet Union, which is embarking on an economic program that could boost energy consumption even higher than it already is?

A growing world population and the associated demand for energy, land, and other resources will also have an impact on carbon emissions. In countries such as Kenya and the Philippines, a three-percent annual growth rate of emissions is just enough to stay even with population, implying static per-capita carbon emissions. Successful efforts to slow population increases would allow such nations to cut emissions more easily. Indeed, unless Third World population growth does slow drastically, it is hard to imagine any global program of carbon reductions that is both sufficient and equitable.

Alternatives to Fossil Fuels

Fossil fuels today provide 78 percent of our energy (oil provides 33 percent; coal 27 percent, and natural gas 18). But we have always known that the world must stop using them eventually since nonrenewable resources are by definition limited and will one day run out. Now the specter of global warming requires us to phase out fossil fuels during the early part of the 21st century, long before reserves are depleted. Not only do they contain carbon, but the extraction and use of fossil fuels contribute a significant share of the emissions of two other greenhouse gases - methane and nitrous oxide.

Although it is important that the transition away from fossil fuels begin in the near future, the process will extend over a period of decades. Many new technologies will have to be developed, and even then installing replacement sources will take time.

Fossil-fuel alternatives include several renewable energy sources poised to develop rapidly. Wind, geothermal, solar thermal, photovoltaic, and various biomass technologies are among the energy sources with potential to move strongly into the market during the '90s. And renewable energy technologies as a group have a big advantage over nuclear power as a means of reducing CO2 emissions: they can be used not only to produce electricity but also to displace many other uses of fossil fuels, such as running autos.

Biomass sources such as wood, agricultural wastes, and garbage have great potential to fuel a sustainable energy system. Already, biomass supplies about 12 percent of world energy, a figure that reaches as high as 50 percent or more in some developing countries. Much of this use is not sustainable, however, and could even exacerbate global warming. In Brazil, for example, smelters fueled by wood from virgin forests emit more carbon dioxide than if they were fueled by coal. Yet with careful management and efficient conversion, these sources could play an important role in a sustainable world energy system.

Wood-and waste-fired power plants are now being built in many nations at costs competitive with those of fossil-fuel plants. They produce minimal air pollution, and as long as they use waste materials or wood from forests that are being replanted, they do not add to CO2 buildup. Power plants that burn methane building up in landfills are particularly effective at slowing global warming, since they consume a gas with 25 times the greenhouse strength of carbon dioxide. A California study found that a kilowatt-hour of electricity produced this way removes methane equivalent to the carbon released by 10 kilowatt-hours generated by a coal-fired plant.

Among the transport fuels that yield substantially lower carbon emissions are alcohol fuels from biomass. Brazil has the world's largest alcohol-fuels program, with about 72 million barrels of ethanol derived from sugarcane annually. In 1988, this provided 62 percent of the country's automotive fuel. Although this huge program has helped reduce Brazil's dependence on imported oil, it has done so at the price of enormous government subsidies. The United States is the second largest producer of alcohol fuels - 20 million barrels per year, derived mainly from corn. But this country is no model either, since its program is also subsidized and is based on a crop grown on prime land. Because fossil fuels are used in the production, U.S. ethanol yields only a 63-percent reduction in carbon emissions on an energy-unit basis.

To make biomass fuels a workable alternative, the world will have to turn to crops grown on marginal lands, to conversion of waste materials, and to the development of integrated cropping systems that allow the same land to produce as much food as at present, and to produce fuel as well.

As societies adopt the slowing of climate change as a guiding principle in selecting energy strategies, it is important that they seize alternatives that are both practical and economical. The relative cost of avoiding carbon emissions is one central consideration for policymakers to keep in mind. In many nations, coal-fired electricity is still the mainstay of the power system, so it makes sense to evaluate technologies that can displace the carbon emitted by this form of energy. Since the fuel and operating costs of a coal-fired power plant are about two cents per kilowatt-hour, and pollution costs about 1.5 cents per kilowatt-hour, anything above 3.5 cents can be attributed to "carbon avoidance."

Significantly more economical than fossil-fuel substitutes are a number of the emerging renewable options, including wind, wood, geothermal, and solar thermal, with carbon-avoidance costs as low as $107 per ton. Moreover, all these costs are falling. The cheapest way to reduce carbon emissions, however, is energy efficiency - enormously abundant and costing a maximum of $19 per ton of avoided carbon. Indeed, many efficiency investments are less expensive than operating existing coal-fired power plants, meaning that the cost of avoided carbon emissions is zero.

Other Greenhouse Strategies

As noted earlier, two important components of efforts to slow global warming are the reversal of deforestation backed by a commitment to replant trees, especially in the Third World, and the elimination of chlorofluorocarbons. The first of these relies on using forests and agricultural lands as a carbon sink.

Several analysts have attempted to estimate the carbon-fixing potential of various kinds of forest, and to design appropriate tree-planting programs. In State of the World 1989 we considered the likely contribution of 130 million hectares (321 million acres) of tropical forest - an area twice the size of France. Trees covering that much territory, planted around the world, could meet the fuelwood and timber needs of the Third World and restore degraded lands. At the same time, they would sequester about 5.5 tons of carbon per hectare. Such a "carbon bank" would absorb 660 million tons of carbon each year until the trees reach maturity in about three decades. This is more than a third of the amount currently thought to be emitted each year by deforestation, and a little under 10 percent of total net carbon emissions.

Slowing deforestation requires that tropical countries end financial incentives for land speculators and settlers to move into virgin forests and for loggers to export hardwoods. Governments and international aid agencies also need to work actively to support sustainable development projects such as agroforestry and woodlots that allow people to make a living from forests that are left standing rather than cutting them down.

Remarkably, in a 1989 policy paper on global warming, the World Bank concluded that "the economics of vigorously pursuing (reforestation) are probably not favorable at this time." This statement ignores the impact of the current rate of deforestation and the potential leverage of the international community in easing the pace of destruction. Stopping deforestation within their own borders is by far the largest contribution that many developing countries can make to global climate stabilization, as well as to their own economic futures.

Countries in temperate regions can also help restore the earth's carbon balance by planting trees. Surveys show that Europe and Japan are the only parts of the world currently increasing their total forested area. Even in Canada and the United States, forests are shrinking, largely due to the spread of land-intensive suburban and commercial development. And in both North America and the Soviet Union, the clearcutting of virgin forests not only continues but is subsidized by governments. Relatively minor policy changes could convert North American, central Asian, and Australian forests into net carbon absorbers. The prime minister of Australia has taken the lead in such efforts with his recent announcement of a program to plant one billion trees by the end of this decade. (And President Bush deftly played one-upsmanship in his January State of the Union speech, calling for the planting of a billion trees a year in the U.S. - Ed.)

A major step in this direction would be to convert large areas of marginal crop and grazing lands to trees, which stabilizes soils at the same time as it increases the rate of carbon fixing. Trees planted, for example, on the 13 million hectares (32 million acres) of erodible cropland set aside in the United States since 1986 under the Conservation Reserve Program would absorb 65 million tons of carbon annually for the first few decades. This would lower U.S. net carbon emissions by about five percent, a major step. Once the new trees reach maturity, in 20 to 30 years, and cease to absorb carbon, they could be harvested on a sustainable basis for use as fuel to replace oil or coal, further lowering carbon emissions.

A number of cities have already decided that the local benefits of tree planting are so great that they will not wait for national governments or the international community to adopt new measures. The American Forestry Association launched a program in late 1988 called Global ReLeaf, [R] which aims to encourage U.S. communities to plant 100 million trees by 1992. This project was spurred by concern over global warming and the desire of individuals to make a contribution. (One hundred million growing trees would sequester an estimated five million tons of carbon annually.)

Global ReLeaf [R] also recognizes that tree planting will improve the urban environment itself, moderating summer heat and improving aesthetics. The mayor of Los Angeles announced in February 1989 that the city hopes to plant between two million and five million trees by 1994, and in September the mayor of Houston, Texas, set forth a plan to plant two million trees by 2000. Other cities are expected to join in.

The real challenge facing these programs is maintaining the trees once they are in the ground. In the past, trees put in during crash campaigns, such as in China, have been plagued by high mortality rates. This can be prevented only by careful nurturing of the saplings. If such difficulties can be overcome, tree planting will make a small but important contribution to climate stabilization. Newly planted trees have an even larger educational and symbolic value, enlisting individuals and their communities in the fight to slow global warming.

A National and Global

Policy Agenda

This past year has been marked by a flurry of proposals to deal with global warming. According to one U.S. count, 130 bills were introduced in 22 state legislatures during the first half of 1989. Major proposals are also being debated in national parliaments (see Table 3). And in some areas, city government and private groups are getting into the act as well. Rarely has a new policy issue taken hold so quickly. [Tabular Data Omitted]

In the United States, two comprehensive global warming bills were first introduced in Congress in late 1988. They proposed a national goal of cutting carbon emissions 20 percent over the next 10 years and included programs to implement national least-cost planning, improve automobile fuel economy, develop renewable energy sources, plant trees, and assist developing countries in slowing population growth and deforestation. In the ensuing months, however, the bills ran into the opposition of entrenched industries, and key elements of the legislation failed to move forward.

The picture in Europe is more encouraging. The public is strongly concerned about climate change, is willing to pay to avoid it, and is electing politicians who are ready to act. The Netherlands, Norway, and Sweden are considering plans to freeze or cut national [CO.sub.2] emissions. In Sweden one oil-fired power project has already been put on hold pending evaluation of its greenhouse impact. The United Kingdom and West Germany report similar sentiments and are reviewing their energy policies. A special West suggest major policy initiatives, but already the opposition Social Democratic Party has called for higher energy taxes, new efficiency incentives, and a sweeping overhaul of utility laws. An inexorable environmental bandwagon may next push the European Parliament, with its dominant coalition of pro-environment parties, to take up related proposals.

Other parts of the world are moving much more slowly on a greenhouse policy agenda. Brazil, China, Japan, and the Soviet Union have done little beyond supporting more research and strong rhetoric. Canada, which has played a leading role in international discussions, failed to reach agreement on a 20-percent-reduction goal at an August 1989 meeting of provincial energy ministers. Some small countries, however, have actively supported new policy initiatives on global warming. These include nations like the Maldives and Malta that believe they may be big losers as the climate changes.

National goals to limit emissions of the four main greenhouse gases - carbon dioxide, CFCs, methane, and nitrous oxide - are among the most important features of any meaningful global warming strategy. But beyond establishing goals, it is important that credible policies be put in place to achieve them, including giving relevant government agencies responsibility to implement useful measures.

It is encouraging that so many governments have begun to mobilize to slow global warming, but an international agreement to stabilize the climate is still needed. Indeed, global warming presents an unprecedented challenge to the global community, forcing everyone from prime ministers to the general public to understand that we inhabit a single planet and share responsibility for its health. National differences and old rivalries will have to be cast aside, so that countries can act in concert as never before.

This seemed to be recognized by leaders of the seven largest industrial democracies, meeting in Paris for their annual summit in July 1989. Environmental proposals occupied one-third of the resulting communique. On global warming, the leaders said, "We strongly advocate common efforts to limit emissions of carbon dioxide and other greenhouse gases, which threaten to induce climate change."

After the rhetoric, however, come complex and difficult negotiations. That process began in November 1988, when representatives of 30 countries met in Geneva under the auspices of the United Nations Environment Programme (UNEP) and the World Meteorological Organization. Following a pattern established in arms talks, these nations have formed an Inter-governmental Panel on Climate Change that will meet periodically to forge an agreement.

The first step is the establishment of ambitious but practical goals for the reduction of carbon emissions, particularly in those countries that currently use fossil fuels most heavily. Any plan that reduces carbon emissions is also likely to help cut back on two other greenhouse gases, nitrous oxide and methane. Only by reducing carbon emissions at least 10 percent in the next decade can the world get on course to at least halve emissions by mid-century.

In an effort to balance practicality and equity against the urgency of the problem, we have formulated a set of reduction targets based on today's per-capita carbon emissions levels (see Table 5). Countries such as the United States and the Soviet Union that currently produce carbon dioxide at a high rate would be required to reduce emissions by about 35 percent in the next 10 years, while nations such as India or Kenya could continue to increase emissions. Those with carbon emissions between these two extremes, such as Italy and Japan, would have to reduce them less rapidly.

The goals are designed to gradually narrow the disparities that now exist among national emissions levels. They are also practical, calling for a realizable 12-percent cut in global emissions by the year 2000 (see Table 6). Under them, projected emissions of 6.4 billion tons are 38 percent below what they will be if the world continues on its current path. Although a 12-percent reduction would not by itself stabilize the climate, it would put the world on a course toward stabilization of global [CO.sub.2] concentrations by mid-century (see Figure 2).

What would a climate-change agreement for the '90s look like? The first element would be a commitment to stabilize atmospheric concentrations of greenhouse gases by the middle of the 21st century, reducing net carbon emissions to a maximum of two billion tons per year. With a projected world population of eight billion, this would imply a per-capita rate of carbon emissions close to India's today, or one-eighth the European level. To get to this point, the world needs to end the production of CFCs and to cut global carbon emissions by 10 to 20 percent over the next decade, adopting country-specific targets based on the per-capita figures described earlier. Within a year of the agreement's signing, each country would submit a plan to achieve the goals, and then issue progress reports every two years. Negotiators, meanwhile, would consider the adoption of stricter goals to begin in 2000.

To accomplish these goals, UNEP would need to become a more powerful agency, given the tasks of coordinating research and of reviewing and assisting with national climate strategies. Verification is essential to a credible agreement. But today UNEP has a minimal budget and is mainly chartered to coordinate the work of larger U.N. organizations. Recognizing this weakness, the leaders of 17 countries, including France, Japan, and West Germany, met in the Netherlands in March 1989. The resulting Hague Declaration called for the development within the United Nations of a strong new institutional authority with powers to carry out the provisions of a global warming agreement.

As the scientific evidence mounts, the time has arrived for a global warming agreement - comprehensive, detailed, and prescriptive. Only a rapid turnaround in carbon-emissions trends can begin to get the world on the path to a stable climate. Wholesale changes in energy, land use, and population policies are implied. Unless such action is taken in the next few years, however, the '90s will become a lost decade for the world's atmosphere, relegating the next generation to a world less able to meet growing human needs. No other environmental problem has such an exponential and cumulative dimension to it, a fact that argues persuasively for the immediate adoption of strong policies.

The benefits of such an effort extend well beyond stabilization of the climate. Economies would be strengthened, new industries created, air pollution reduced, and forests preserved for their economic and recreational benefits. For humanity as a whole, it would be another step in the evolution of society, demostrating the ability to work cooperatively as a world community. It would be an auspicious beginning to the new millennium. [Tabular Data Omitted]

PHOTO : Figure 2-1. Carbon Emissions from Fossil Fuels, 1950-88

PHOTO : Figure 2-2. Carbon Emissions from Fossil Fuels, 1950-88, With Alternative Projections to 2010

Christopher Flavin is vice president for research at Worldwatch Institute, a nonprofit research group devoted to analyzing global environmental issues,