This paper quantifies how African farmers have adapted their crop and irrigation decisions to their farm's current agro-ecological zone. The results indicate that farmers carefully consider the climate and other conditions of their farm when making these choices. These results are then used to forecast how farmers might change their irrigation and crop choice decisions if climate changes. The model predicts African farmers would adopt irrigation more often under a very hot and dry climate scenario but less often with a mild and wet scenario.

This report develops a Structural Ricardian model to measure climate change impacts that explicitly models the choice of farm type in African agriculture. This two stage model first estimates the type of farm chosen and then the conditional incomes of each farm type after removing selection biases.

pharmaceutical giant GlaxoSmithKline is recalling its malaria drug Lapdap and has discontinued development of another malaria drug, Dacart, saying the drugs can lead to anaemia in some patients.

Enlarge View   an international research team has provided the first scientific evidence that deadly emerging diseases have risen steeply across the world,

Food scientists are meeting in Cusco, Peru, this week to find ways of boosting world potato production to ease the strain of surging cereal prices on the world's poorest countries. Potato production already reached a record high last year as cereal prices rose, partly as a consequence of grain producers - such as the US - switching to bio-fuel crops. The impact of more expensive cereals has been harshest on developing countries that are dependent on imports.

In Africa, hard-hit by HIV, the proportion of TB drug-resistance is no less alarming. In former Soviet Union, almost half of all TB cases are resistant to at least one anti-TB drug -Bobby Ramakant

Abstract Black carbon in soot is the dominant absorber of visible solar radiation in the atmosphere. Anthropogenic sources of black carbon, although distributed globally, are most concentrated in the tropics where solar irradiance is highest. Black carbon is often transported over long distances, mixing with other aerosols along the way. The aerosol mix can form transcontinental plumes of atmospheric brown clouds, with vertical extents of 3 to 5 km.

In the 7 December 2007 issue, L. Roberts and M. Enserink discuss malaria eradication in the News Focus Story "Did they really say..eradication?" Information from India's 5-year economic plans shows that even if complete eradication cannot be secured, economic gains and reduced suffering may be worth the effort. (Letters)

Rinderpest, an animal disease that devastated cattle and other animals-and their human keepers-across Eurasia and Africa for millennia, may join smallpox as the only viral diseases to have been eradicated.

Sir, It is appalling that in 2008 you still publish articles such as "Africa's greatest challenge is to reduce fertility' (March 14) by John May and Jean-Pierre Guengant.