Is there one word that sums up what the world needs more of? That’s the question posed by the UN for this year’s World Humanitarian Day, when it pledges to “turn those words into currency”. Change, peace, hope and teamwork (the latter as favoured by UN Secretary-General Ban Ki-Moon) spring instinctively to mind. Along with justice and equality, they are among the trending suggestions in the run up to 19 August. But just how realistic is it to think that words have the power to accelerate global change to the extent that is needed?