At one end of the facility is a small out-patient clinic where people who can pay $1 a day receive life-sustaining AIDS drugs. “They take the medicine and they get better,” Sachs declares. “They return to work. They go back to caring for their children.” Unfortunately, $1 a day is nearly twice what a typical Malawian lives on. So most AIDS patients end up in wards like the one just down the hall from the outpatient clinic. There 450 emaciated souls lie crammed into 160 cots, moaning softly and waiting for death to end their misery. “Ladies and gentlemen,” Sachs tells the now hushed hall, “this plague is exploding. Its consequences will make the world quake. Rich countries could stop the devastation. And most are still looking away.”

Sachs is not the first to sound this alarm, but he speaks with special authority. As the newly appointed director of Columbia University’s Earth Institute, he heads a huge, interdisciplinary effort to help poor countries build sustainable economies. Instead of treating soil depletion, climate change, epidemic disease and social upheaval as distinct phenomena, the institute’s 800 scientists study the links among such problems–and work to translate their insights into action. Sachs also chairs blue-ribbon panels for the World Health Organization, advises U.N. Secretary-General Kofi Annan on development issues and circles the globe pleading with policymakers to support the fledgling Global Fund to Fight AIDS, Tuberculosis and Malaria. In the coming year he’ll help seed new treatment-and-prevention programs throughout Asia and Africa. He’ll also work with government ministers in China, India and other high-risk countries to improve overall health services.

From Sachs’s perspective, controlling AIDS is not only a moral imperative but also a practical necessity. As he is forever trying to convince political leaders, disease can perpetuate poverty, ruin economies and undermine civic order. As a Sachs-led WHO commission concluded last year, “The burden of disease in some low-income regions… stands as a stark barrier to economic growth and must be addressed frontally and centrally in any comprehensive development strategy.” As a group, the world’s richest countries now spend just $6 billion a year in health-related development assistance. The Sachs commission concluded that by raising the commitment to $27 billion by 2007 and $38 billion by 2015, we would save 8 million lives every year–while improving a third of the world’s prospects for prosperity.

Will that dream come true? The U.S. government could have gotten on the Sachs track by spending at least $2.5 billion on AIDS, TB and malaria this past year. The Bush administration pledged less than $1 billion, while pressing ahead with Middle East war plans that could cost $100 billion or more. Sachs doesn’t doubt that priorities will shift as the pandemic grows. The issue that worries him–and it’s a big one–is how long the awakening will take.