Pope Francis has said he got stuck in a lift for 25 minutes at the Vatican and had to be rescued by firefighters.

The pontiff apologised to the faithful gathered in St Peter’s Square on Sunday for showing up seven minutes late to his traditional noon appointment with the public.

Apparently referring to electric power, Francis said a “drop in tension” caused the problem. He said he was rescued by Holy See firefighters and asked the people in the square to applaud them.

In his address he challenged governments to take “drastic measures” to combat global warming and reduce the use of fossil fuels, saying the world was experiencing a climate emergency.

Francis issued his appeal, a written message for Sunday’s World Day of Prayer for the Care of Creation, ahead of the United Nations Climate Action Summit this month in New York, a follow up to the 2016 Paris Agreement to curb global warming.

Calling the UN summit “of particular importance,” he added: “There, governments will have the responsibility of showing the political will to take drastic measures to achieve as quickly as possible zero net greenhouse gas emissions and to limit the average increase in global temperature to 1.5 degrees Celsius with respect to pre-industrial levels, in accordance with the Paris Agreement goals.”

The pope also announced that he will elevate 13 Roman Catholic prelates to the rank of cardinal next month, including 10 “cardinal electors” under 80 years old and thus eligible to vote in an eventual conclave to choose his successor. They come from countries including Indonesia, Cuba, Luxembourg, Morocco and the Democratic Republic of Congo.