Climate change could hit crops far worse than thought

SciDev.net: The impact of climate change on key food crops in Africa and South Asia may be much worse than previously estimated — with reductions of up to 40 percent by the 2080s — according to a study, which synthesised results from related studies published over the last 20 years. It also identified "major gaps in climate change impact knowledge" for certain crops and regions, such as central Africa. Such lack of knowledge could hamper effective adaptation policy decisions, it warns.

The study projects an eight per cent average decrease for all crop yields — and this figure increases to 40 per cent in worst-case scenarios. In Africa, the most significant yield reductions are predicted for maize, millet, sorghum and wheat, while in South Asia, maize and sorghum will be hardest hit.

The study looked at more than 1,140 publications that have projected the impact of climate change on eight key food and commodity crops (rice, wheat, maize, sorghum, millet, cassava, yam, and sugarcane) that together account for more than 80 per cent of total crop production in the two regions,   and then analysed 52 of those studies in depth.

The strength of evidence on how severe the impact will be differed for different crops and regions. In Africa, just six out of 162 observations from the scientific publications analysed were about rice, yam and sugarcane, despite these accounting for almost a third of Africa's cropped area.

The study says that that the development of new crop varieties and uptake of new technologies — the most costly adaptation options — are likely to bring the most benefits....

Starting a new rice crop near Hanoi, public domain