Some of the practical results that could emerge from the 2005 World Summit are global actions with high short-term impact on the fight against poverty. The final communique looks set to include a section on "Quick Impact Initiatives" and another on the special needs of Africa that, if followed, would have an enormous effect on global poverty by the end of the decade.

The two points of most significance involve the fight against malaria and the fight against hunger in Africa.

The declaration calls for quick actions against malaria in two critical areas: mass distribution of insecticide-treated bed nets and the mass availability of effective medicines. Repeated trials throughout African villages have shown that the intensive use of these special bed nets, when combined with access to the improved medicines, can reduce malaria illness and death decisively. More than 1m children could be saved each year, and at a cost of just Dollars 3 (Euros 3.70, Pounds 2.10) per person from the donor countries.

The evidence is clear that stopping malaria would not only end a tremendous amount of suffering and needless death, but would also be a major spur to longer-lasting economic development. Malaria cuts not only African incomes, but also growth prospects.

Ironically, the millions of children's deaths from malaria each year induce impoverished households to maintain high fertility rates, in the fear that children will not survive. Reducing malaria deaths would actually reduce fertility by an even larger amount, thereby slowing population growth. It would also raise labour productivity, school performance and the ability to attract foreign investment.

A second key measure in the declaration is for an African Green Revolution. This year has been another of intense hunger crises throughout the continent; "emergencies" have become chronic rather than exceptional. The deeper reasons are clear enough. While Africa's rural populations have risen, farm techniques have not improved. Most subsistence farmers in Africa continue to farm without high-yield seeds, fertilisers, modern agro-forestry techniques, and small-scale irrigation and other water management.

It is no mystery what to do. Impoverished farmers need improved inputs of seed, nutrients, and water management. Their yields could triple within the next few farming cycles. The cost of those inputs would be a fraction, perhaps a fifth or a tenth, what it would cost to make up the difference in food aid shipped from the US and Europe.

Yet for two decades the donor countries and World Bank have resisted subsidising the inputs to farming, preferring instead to ship food aid.

This is now changing. The World Bank and others are realising that, with directed help to impoverished farmers to obtain scientifically based farm inputs, it will be possible to help spur a Green Revolution for Africa.

The results could be equivalent to Asia's Green Revolution 40 years ago. There, too, subsidised farm inputs in the early years helped farmers to introduce high-yield seed varieties with fertilisers and irrigation.

Yields soared, famines disappeared and Asian economies moved from agricultural stagnation and cycles of famine to sustained food adequacy at the national scale and an opening to manufacturing and service-sector-led growth. It is now Africa's turn

Cynics complain that United Nations goal-setting is just pie in the sky, without a connection to ground reality. The Millennium Development Goals, however, are different. They can be achieved, precisely, through practical investments in proven areas. Slowly, fitfully, the world community seems to be coming around to such a practical plan.

Professor Jeffrey D. Sachs is director of the Earth Institute at Columbia University. For his daily UN summit blog, go to www.ft.com/ sachs