BBC: El Nino events can have a significant impact on the yields of certain major food crops, a study has shown. Researchers say the climatic phenomenon, which triggers changes in temperature and rainfall, can reduce maize yields by more than 4%. El Nino episodes are caused by changes in the sea surface temperature in the eastern tropical Pacific Ocean. Writing in Nature Communications, the team said the data could be used by governments to manage food supplies. They wrote: "Results show that El Nino...