Predicting what the future holds is nearly always a risky pursuit. We can examine and dissect events past, trends and patterns, but do we ever really know what is to come? We do in one case: America will elect a new president in 2016, ending President Barack Obama’s second term. And experts agree overwhelmingly that the world will continue to be plagued by the threat of terrorism. But what about the global economy? Gun violence? The Iran nuke deal? Europe’s migrant crisis? Some of the world’s most pressing issues will be stubbornly familiar and hard to remedy; others are likely to emerge as new challenges in a new year.