IN THE PAPERS - Monday, September 23: The UN Climate Action summit dominates newspapers globally. "It's now or never" is the headline on the front page of Libération. The French daily urges world leaders to curb carbon emissions and criticises Emmanuel Macron for failing to take the lead. Meanwhile, tensions in the Arab-Persian Gulf are high on the agenda at this week's UN General Assembly. We end with coverage of the "Mediator" trial in France, one of the country's biggest healthcare scandals.