VATICAN CITY – Pope Francis arrived late for his weekly address in St. Peter’s Square on Sunday, explaining that he had been stuck in an elevator in the Vatican for 25 minutes and had to be freed by firefighters.

“I have to beg your pardon,” the smiling pontiff said as he started the address about 10 minutes late.

He then explained that there had been a electrical power problem in the Vatican and that he had been stuck in the elevator until freed by Vatican fire officers.

“A round of applause for the fire brigade,” he told the crowd.

Pope Francis leaves on Wednesday for Africa, where poverty, the environment, foreign exploitation of resources and corruption are expected to be high on his agenda as he visits the continent where Catholicism is growing fast.

He will spend most of the September 4-10 trip in Mozambique and Madagascar and briefly visit Mauritius at the end.

Fires in the Amazon have given new urgency to the pope’s calls to protect the environment, tackle climate change and promote sustainable development.

Aides say the trip, his second trip to sub-Saharan Africa, is a key opportunity to renew appeals enshrined in his 2015 encyclical “Laudato Si” on environmental protection.

Rampant deforestation has plagued Mozambique and Madagascar. Deforestation, along with soil erosion, made Mozambique more vulnerable when two cyclones hit the country this year.

According to the World Bank, Mozambique has lost 8 million hectares of forest, about the size of Portugal, since the 1970s.

“Here in Mozambique we like to say that not even our wood is ours because the Chinese are taking it all away, said Costantino Bogaio, head of the Comboni religious order in Mozambique. “The earth is ours and we have to protect it more.”

As Asian supplies of valuable hardwoods like rosewood used to make luxury furniture have been depleted, Chinese importers have shifted to Africa. Mozambique is currently the 10th-largest supplier of rosewood to China, according to Chinese customs data cited by U.S.-based non-profit group Forest Trends.

In Madagascar, the world’s fourth-largest island, about 44 percent of forests have disappeared over the past 60 years, according to the French agricultural research centre CIRAD. The environmental danger there is aggravated because 80 percent of its plant and animal species are not found anywhere else.

Poverty, war and corruption will also loom large during the trip.

According to the U.N. World Food Programme (WFP), 80 percent of Mozambique’s population of about 30 million cannot afford the minimum costs for an adequate diet.

The WFP says more than 90 percent of Madagascar’s population of 26 million live on less than US$2.00 a day and chronic child malnutrition is widespread.

Francis has called for a fairer distribution of wealth between prosperous and developing countries and defended the right of countries to control their mineral resources.

“We must invest in Africa, but invest in an orderly way and create employment, not go there to exploit it,” the pope told Reuters in an interview last year.

“When a country grants independence to an African country it is from the ground up – but the subsoil is not independent. And then people (outside Africa) complain about hungry Africans coming here. There are injustices there!” he said.

Mozambique, a former Portuguese colony, emerged from 15 years of civil war in 1992 but it was only last month that President Filipe Nyusi of the ruling Frelimo party and the leader of the Renamo opposition, Ossufo Momade, signed a permanent cease-fire.

“I think he is going to give a forceful message to the country’s leaders about their responsibility to bring about peace and reconciliation, but also about addressing the root cases of the conflict,” said Erica Dahl-Bredine, Mozambique country representative for Catholic Relief Services.

She said unequal sharing of wealth from extraction industries could spark new conflict.

Francis has called corruption “one of the most decimating plagues” in society.

Mozambique and Madagascar rank in the lowest quarter of Transparency International’s Corruption Perceptions Index.

“Corruption is huge. Many Mozambicans have lost faith completely in their political leaders,” said Dahl-Bredine.

Catholicism in Africa grew by 238 percent between 1980 and 2015, according to the Centre for Applied Research in the Apostolate at Georgetown University. This continuing growth gives the Church increasing influence.

Francis makes an eight-hour stop in Mauritius, a small island in the Indian Ocean that is rich compared Madagascar and Mozambique.

But anti-poverty campaigners say Mauritius’ tax treaties and financial services industry facilitates tax avoidance, draining desperately-needed revenues from poor countries.

Francis will pay tribute to Jacques-Dèsirè Laval, a 19th century French priest who helped former slaves on what was then a British colony. – Reuters