10个想法改变世界：共同财富

By JEFFREY D. SACHS

The 21st century will overturn many of our basic assumptions about economic life. The 20th century saw the end of European dominance of global politics and economics. The 21st century will see the end of American dominance too, as new powers, including China, India and Brazil, continue to grow and make their voices heard on the world stage. Yet the century's changes will be even deeper than a rebalancing of economics and geopolitics. The challenges of sustainable development—protecting the environment, stabilizing the world's population, narrowing the gaps of rich and poor and ending extreme poverty—will render passé the very idea of competing nation-states that scramble for markets, power and resources.

The defining challenge of the 21st century will be to face the reality that humanity shares a common fate on a crowded planet. We have reached the beginning of the century with 6.6 billion people living in an interconnected global economy producing an astounding $60 trillion of output each year. Human beings fill every ecological niche on the planet, from the icy tundra to the tropical rain forests to the deserts. In some locations, societies have outstripped the carrying capacity of the land, resulting in chronic hunger, environmental degradation and a large-scale exodus of desperate populations. We are, in short, in one another's faces as never before, crowded into an interconnected society of global trade, migration, ideas and, yes, risk of pandemic diseases, terrorism, refugee movements and conflict.

We also face a momentous choice. Continue on our current course, and the world is likely to experience growing conflicts between haves and have-nots, intensifying environmental catastrophes and downturns in living standards caused by interlocking crises of energy, water, food and violent conflict. Yet for a small annual investment of world income, undertaken cooperatively across the world, our generation can harness new technologies for clean energy, reliable food supplies, disease control and the end of extreme poverty.

That's why the idea that has the greatest potential to change the world is simply this: by overcoming cynicism, ending our misguided view of the world as an enduring struggle of "us" vs. "them" and instead seeking global solutions, we actually have the power to save the world for all, today and in the future. Whether we end up fighting one another or whether we work together to confront common threats—our fate, our common wealth, is in our hands.

To make the right choice, we must understand four earth-changing trends unprecedented in human history:

First, the spread of modern economic growth means that the world on average is rapidly getting richer in terms of incomes per person. Moreover, the gap in average income per person between the rich world, centered in the North Atlantic (that is, Europe and the U.S.), and much of the developing world, especially Asia, is narrowing fast. With well over half the world's population, fast-growing Asia will also become the center of gravity of the world economy.

Second, the world's population will continue to rise, thereby amplifying the overall growth of the global economy. Not only are we each producing more output on average, but there will be many more of us by midcentury. The scale of the world's economic production by midcentury is therefore likely to be several times that of today.

Third, our bulging population and voracious use of the earth's resources are leading to unprecedented multiple environmental crises. Never before has the magnitude of human economic activity been large enough to change fundamental natural processes at the global scale, including the climate itself. Humanity has also filled the world's ecological niches; there is no place to run.

Fourth, while many of the poor are making progress, many of the very poorest are stuck at the bottom. Nearly 10 million children die each year because their families, communities and nations are too poor to sustain them. The instability of impoverished and water-stressed countries has ignited a swath of violence across the Horn of Africa, the Middle East and Central Asia. What we call violent fundamentalism should be seen for what it really is: poverty, hunger, water scarcity and despair.

These great challenges have not entirely escaped worldwide notice. In the past 20 years, world leaders on occasion have groped for ways to cope with them. In fact, they've achieved some important successes, and with considerable public support, which can provide a foothold for a sustainable future. We have adopted a global treaty for climate change; we have pledged to protect biodiversity; we are committed globally to fighting the encroachment of deserts in today's conflict-ridden dry lands of Africa, the Middle East and Asia. And the world has adopted the Millennium Development Goals to cut extreme poverty, hunger and disease by 2015. The challenge is to turn those fragile and unfulfilled global commitments into real solutions.

Global Goals
When it comes to problem-solving on a global scale, we remain weighed down by cynicism, defeatism and outdated institutions. A world of untrammeled market forces and competing nation-states offers no automatic solutions to these challenges. The key will lie in developing new sustainable technologies and ensuring that they rapidly reach all those who need them. If the trillions of dollars that the U.S. is squandering in Iraq was instead being invested in clean energy, disease control and new, ecologically sound ways of growing food, we wouldn't be facing the cusp of a rapidly weakening dollar, soaring food and energy prices and the threats of much worse to come.

Here are four bold but achievable goals for the U.S. and the rest of the world: — Sustainable systems of energy, land and resource use that avert the most dangerous trends of climate change, species extinction and destruction of ecosystems
— Stabilization of the world population at 8 billion or below by 2050, through a voluntary reduction of fertility rates, rather than the current trajectory of more than 9 billion by midcentury
— The end of extreme poverty by 2025, and improved economic security within the rich countries as well
— A new approach to global problem-solving based on cooperation among nations and the dynamism and creativity of the nongovernmental sector.

What will it take to attain these goals? The greatest successes in global cooperation combine four elements: a clear objective, an effective technology, a clear implementation strategy and a source of financing.

Smallpox eradication, for example, started with a clear objective (the eradication of the disease) and an effective vaccine. It built on a clear implementation strategy, in which smallpox vaccines were given for free on a mass basis, and local outbreaks were quickly isolated through careful surveillance and response. The effort was funded on a sustained basis by several donor governments, including the U.S.'s. Similarly, the Green Revolution in Asia, which lifted China and India out of chronic hunger, built on a clear objective (raising food yields), an effective technology (a combination of high-yield seeds, fertilizer and irrigation), a clear implementation strategy (mass distribution of the input package at below market cost) and large-scale funding (from the Ford and Rockefeller foundations and the U.S. government, in addition to local financing).

Other examples abound of measurable progress against once daunting challenges: the rapid, if incomplete, expansion of primary schooling and literacy around the world; the systematic control of many killer diseases, including guinea worm disease, leprosy and African river blindness; and the voluntary decline of high fertility rates through access to family planning in almost all parts of the world, with sub-Saharan Africa the last remaining region awaiting a "demographic transition."

We live in a time of cynicism about achieving global public goals, yet whenever we have made the effort to mobilize our powerful technologies, we have succeeded. Measles deaths in Africa are down more than 90% in the past seven years, at a time when many people mistakenly believe that nothing can be accomplished in large parts of Africa. Polio is nearly eradicated. Food production is soaring in Ethiopia and Malawi because modern farming techniques have been brought to peasant communities. Children have filled the schools wherever school meal programs are introduced and school fees are dropped. There is no shortage of examples of how we can attain our goals, only a shortage of will and stamina so far to carry these successes to scale, and to other vital arenas.

Our generation's great environmental challenges can be met with similar resolve and technological focus. Climate change threatens our food supplies, coastlines, health and the survival of countless species. Yet powerful technological solutions are within reach. Coal-fired power plants can capture and store the carbon dioxide that they produce, rather than releasing the carbon dioxide into the atmosphere.

Plug-in hybrid automobiles, nearly ready for the market, have the potential to quadruple our miles per gallon. Solar energy, concentrated by rapidly improving systems of parabolic mirrors, could be deployed in Africa's great desert and dry-land regions to provide electricity for Africa and Southern Europe at a cost competitive with fossil fuels. New land-management strategies, backed by modest financial incentives, could end most of today's tropical deforestation, which now contributes around one-fifth of all global carbon emissions as well as causing a massive loss of biodiversity. And all these steps to sustainable energy, according to today's best economic and engineering evidence, can be implemented for less than 1% of annual world income.

Beyond Markets
If the solutions are so attainable, why haven't we reached them already? Part of the reason is that we are facing our problems in the wrong way. We are so convinced that the problems are intractable—or deathly expensive to solve—that paralysis reigns. Even when we are aware of what needs to be done, we are often trapped by a free-market ideology, the same kind of no-regulation policy that has led us into our current financial crisis.

On the three great challenges—environmental sustainability, a stable world population and the end of extreme poverty—market forces will not be enough. The world's producers and consumers currently regard the air as a free dumping ground for carbon dioxide and other climate-changing greenhouse gases. We need to correct market forces—for example, by taxing carbon emissions that are offset by tax reductions elsewhere—in order to create the right incentives. We need to expand greatly our public investments in early-stage clean technologies, such as improved solar-thermal power and carbon capture and sequestration, just as the National Institutes of Health uses public funding to support medical breakthroughs.

Similarly, population stabilization in poor countries requires a determined public investment—in girls' education, health services and child survival—to promote a rapid and voluntary reduction in birth rates. And we should first help the poorest of the poor to get above survival levels of income before we can expect market forces to lift them further, to market-driven prosperity.

None of this is expensive, but none of it can happen by itself. Indeed, it is the low cost of success that is perhaps the most remarkable feature of all. Consider malaria, the great African killer disease. Three hundred million antimalaria bed nets are needed to protect impoverished Africans from the disease. Each net costs $5 and lasts five years, for a total cost of $1.5 billion over five years. Yet that is less than one day's Pentagon spending! Add in the costs of medicines and ongoing delivery services, and we find that comprehensive malaria control would cost less than two days' Pentagon spending each year. Sustainable development will not break the bank. The key is, rather, to make the right choices in our public investments and to find ways to harness, and channel, market forces.

The Power of One
Great social transformations—the end of slavery, the women's and civil rights movements, the end of colonial rule, the birth of environmentalism—all began with public awareness and engagement. Our political leaders followed rather than led. It was scientists, engineers, church-goers and young people who truly led the way. If as citizens we vote for war, then war it will be. If instead we support a global commitment to sustainable development, then our leaders will follow, and we will find a way to peace.

Each of us has a role to play and a chance for leadership. First, study the problems—in school, in reading, on the Web. Second, when possible, travel. There is no substitute for seeing extreme poverty, or deforestation, or the destructive forces of nature in New Orleans, to understand our generation's real challenges. There is no substitute for meeting and engaging with people across cultures, religions and regions to realize that we are all in this together. Third, get your business, community, church or student group active in some aspect of sustainable development. Americans are promoting the control of malaria, the spread of solar power, the end of polio and the reversal of treatable blindness, to name just a few of today's inspiring examples of private leadership. Finally, demand that our politicians honor our nation's global promises and commitments on climate change and the fight against hunger and poverty. If the public leads, politicians will surely follow.

Our generation's greatest challenges—in environment, demography, poverty and global politics—are also our most exciting opportunity. Ours is the generation that can end extreme poverty, turn the tide against climate change and head off a massive, thoughtless and irreversible extinction of other species. Ours is the generation that can, and must, solve the unresolved conundrum of combining economic well-being with environmental sustainability. We will need science, technology and professionalism, but most of all we will need to subdue our fears and cynicism. John F.Kennedy reminded us that peace will come by recognizing our common wealth. "If we can not end now our differences, at least we can help make the world safe for diversity. For, in the final analysis, our most basic common link is that we all inhabit this small planet. We all breathe the same air. We all cherish our children's future. And we are all mortal."

Sachs, author of The End of Poverty, directs the Earth Institute at Columbia University