As the Secretary-General has said, climate change continues to move faster than our efforts to address it. Amid record-breaking temperatures in parts of the world, and with the past two decades the warmest on record, the Secretary-General delivered a major address at UN Headquarters on 10 September. Speaking to an audience of young people, business leaders, journalists and diplomats on the eve of the Global Climate Action Summit in San Francisco and the annual gathering of world leaders for the opening of the new General Assembly session in New York, he outlined the danger, highlighted solutions, and emphasized the need for greater ambition and stronger leadership in addressing what he has called “the defining threat of our time”.