By Clár Ní Chonghaile for the Guardian. 

For three days this week, New York will be the centre of the world when the pope, presidents and pop stars descend on the city to ratify the sustainable development goals and celebrate the start of a new era.

The summit will adopt a new set of priorities and pledges meant to end poverty and huger, fight inequality and injustice, and achieve gender equality by 2030. Those are some of the broad aims of the 17 sustainable development goals due to be ratified by the UN’s 193 members on Friday.

But the men and women gathered in New York will be acutely aware that this defining moment is taking place against the backdrop of multiple global challenges – from the worst refugee crisis since the second world war to the threat of dramatic climate change.