The flags of all the UN countries that flank the famous building in New York billowed in the gentle April breeze. I had stepped outside for a bit of fresh air and to call my office in London.

I had just heard Douglas Alexander, the British Development Minister, say that  ‘additional finance needs to be brought on stream to meet the unpredicted costs of climate change’. These words – conceding the need for extra money – had never been used by him in Britain.