<p>Droughts in southern Europe have led to a drop in the production of nuts such as almonds and pistachios."We expect a 23 pct drop in almond production this year from last year," Jose Ugarrio, analyst at the Spanish young farmers' association said.Some see rising temperatures as a long-term trend, which threatens the viability of farming in the region.</p> <p>"In this situation ... you realise it's almost impossible to keep going. You think OK, this year I will try to manage, but if the harvest is like this next year you won't be able to cope any more," said farmer Tocchi, who is also the local head of farmers' group Confagricoltura.Some scientists have said heat waves like this year's are becoming more frequent, and are linked to man-made climate change.</p>