The causes of such humanitarian crises are many and varied. They may be the result of extreme weather conditions — too much or too little rain, high winds or heavy snows — or a devastating earthquake or volcanic eruption. Often they are the tragic by-products of conflict, as warring factions fight over land or scarce resources, destroying people’s livelihoods and forcing them to flee their homes. Sometimes national economic mismanagement makes the poor destitute and turns hunger into famine. Whether their causes are natural or man-made, such crises invariably bring great human suffering.