ROME — Pope Francis recalled a massive storm that struck northern Italy last fall, saying such natural disasters are nature’s way of sounding an alarm to make us more environmentally engaged.

Speaking in Saint Peter’s Square for the inauguration of the Vatican Christmas tree and Nativity scene on Thursday, the pope thanked the people of the regions of Veneto and Trentino-Alto Adige, who donated the tree and crèche scene.

“Today’s meeting offers me the opportunity to renew my encouragement to your people, who last year suffered a devastating natural disaster, with the demolition of entire wooded areas,” Francis said. “These are events that frighten us; they are alarm signals that creation sends us, which summon us to immediately take effective decisions to safeguard our common home.”

Thanking the people for the large spruce tree at the center of the square as well as a number of the smaller trees that will be placed around the Vatican, Francis said he was “pleased to learn that 40 fir trees will be planted to replace the trees that have been removed trees and to replenish the woods that were severely damaged by the storm of 2018.”

In 2015, Pope Francis became the first Roman pontiff in history to devote an entire encyclical letter to the issue of care for the environment, in which he decried human exploitation of nature.

The earth “now cries out to us because of the harm we have inflicted on her by our irresponsible use and abuse of the goods with which God has endowed her,” Francis wrote. “We have come to see ourselves as her lords and masters, entitled to plunder her at will. The violence present in our hearts, wounded by sin, is also reflected in the symptoms of sickness evident in the soil, in the water, in the air and in all forms of life.”

“Now, faced as we are with global environmental deterioration, I wish to address every person living on this planet,” the pope continued, comparing the ecological crisis to the nuclear crisis of the Cold War era.

Since then, the pope has become one of the most vocal opponents of global warming, urging “drastic measures” to combat “a climate emergency that gravely threatens nature and life itself.”

“Too many of us act like tyrants with regard to creation,” he declared. “Let us make an effort to change and to adopt more simple and respectful lifestyles!”

“Now is the time to abandon our dependence on fossil fuels and move, quickly and decisively, towards forms of clean energy and a sustainable and circular economy. Let us also learn to listen to indigenous peoples, whose age-old wisdom can teach us how to live in a better relationship with the environment,” he said.

Just this week, Francis scolded political leaders for their half-hearted response to the climate crisis, suggesting that their “weak” resolve in cutting emissions reveals a lack of political will.

In his message to the participants in the COP25 United Nations convention on climate change, the pope reiterated his conviction that climate change is “one of the main challenges for humanity” because it threatens the future of the human race.

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