Ve have read the science. Global warming is real, and we are a prime cause. We have heard the warnings. Unless we act, now, we face serious consequences. Polar ice may melt. Sea levels will rise. A third of our plant and animal species could vanish. There will be famine around the world, particularly in Africa and Central Asia. Largely lost in the debate is the good news. We can do something about this-more easily, and at far less cost, than most of us imagine. These are the conclusions of the latest report from the Intergovernmental Panel on Climate Change, the scientific body that recently shared the Nobel peace prize. It is sobering reading, but we must not miss its optimistic bottom-line: to repeat, we can do this - in ways that are both affordable and promote prosperity. This week, world leaders gather for the summit in Bali. We need a break-through: a comprehensive climate change agreement that all nations can embrace. We must set an agenda - a roadmap to a better future, coupled with a tight timeline that produces a deal by 2009. We do not yet know what such an accord might look like. Should it tax greenhouse gas emissions, or create an international carbon-trading system? Should it provide mechanisms for preventing de-forestation, accounting for 20 percent of CO2 emissions, or help less developed nations adapt to the inevitable effects of global warming - effects weighing disproportionately on them? Should it emphasize conservation and renewable fuels, like biomass or nuclear power, and make provisions for transferring new "green technologies around the world? The answer, of course, is some variation on all the above - and much, much more. If the negotiations bog down in the sheer breadth and complexity of the issues, we lose our most precious resource: time. In this, it helps to have a vision of how the future might look, if we succeed. That is not merely a cleaner, healthier, more secure world for all. Handled correctly, our fight against global warming could, in fact, set the stage for an eco-friendly transformation of the global economy - one that spurs growth and development rather than crimps it, as many national leaders fear. We have witnessed three economic transformations in the past century. First came the industrial revolution, then the technology revolution, followed by our modern era of globalization. We stand, now, at the threshold of another great change: the age of green economics. The evidence is all about us, often in unexpected places. Visiting South America recently, I saw how Brazil has become one of the biggest players in green economics, drawing some 44 percent of its energy needs from renewable fuels. World average: 13 percent. The figure in Europe: 6.1 percent. Much is made of the fact that China is poised to surpass the United States as the world's biggest emitter of greenhouse gases. Less well-known, however, are its more recent efforts to confront grave environmental problems. China will invest $10 billion in renewable energy this year, second only to Germany. It has become a world leader in solar and wind power. At a recent summit of East Asian leaders in Singapore, Premier Wen Jiabao pledged to reduce energy consumption (per unit of GDP) by 20 percent over five years - not so far removed, in spirit, from Europe's commitment to a 20 percent reduction in greenhouse gas emissions by 2020. This is the way of the future. According to some estimates, growth in global energy demand could be cut in half over the next 15 years simply by deploying existing technologies yielding a return on investment of 10 percent or more. The new IPCC report lays out the very practical ways, from tougher standards for air conditioners and refrigerators to improved efficiency in industry, building and transport. It estimates that overcoming climate change may cost as little as 0.1 percent of global GDP a year over the next three decades. Growth need not suffer and in fact may accelerate. Research by the University of California at Berkeley indicates that the United States could create 300,000 jobs if 20 percent of electricity needs were met by renewables. A leading Munich consulting firm predicts that more people will be employed in Germany's enviro-technology industry than in the auto industry by the end of the next decade. The UN Environment Program estimates that global investment in zero-greenhouse energy will reach $1.9 trillion by 2020 - seed money for a wholesale reconfiguration of global industry. Already, businesses in many parts of the world are demanding clear public policies on climate change, regardless of what form they might take - regulation, emissions caps, efficiency guidelines. The reason is obvious. Business needs ground rules. Helping to create them is very much the role of the United Nations. Our job, in Bali and beyond, is to shape this nascent global transformation - to open the door to the age of green economics and green development. What's missing is a global framework within which we, the world's peoples, can coordinate our efforts to fight climate change. The scientists have done their job. Now it's up to the politicians. Bali is a test of their leadership. What are we waiting for? Ban Ki-moon is Secretary-General of the United Nations
