Droughts and heat waves have tripled in Europe Droughts and heat waves have tripled in the last 50 years in Europe, with a corresponding reduction in harvests, especially cereals, indicates a study developed by three researchers from Universidade Nova. The study, published in the scientific journal "Environmental Research Letters", warns that the effects of climate change on harvests can lead to food shortages and higher prices. Teresa Armada Brás, the researcher who led the study, explained to Lusa that, although there are many investigations that show the increase in the frequency of extreme climate events, the losses in agriculture associated to these events have not been studied.