Pope Francis highlighted on Monday what he considers two main threats to humanity, namely the “immense crisis” of global warming and the possibility of nuclear war.

In his address to the Pontifical Academy of Sciences, the pope urged his listeners to do all they can to assist humanity in facing the most pressing threats facing the planet, noting that in the first place these are “the immense and ongoing crisis of climate change and the nuclear menace.”

Human actions are at the root of many global changes, the pontiff insisted, especially where climate change is concerned. “Hence there is also a need for adequate responses aimed at protecting the health of the planet and its inhabitants, a health put at risk by all those human activities that employ fossil fuels and deforest the planet.”

Just as the scientific community, he said, “has made progress in identifying these risks, it is now called to propose workable solutions and to convince societies and their leaders to pursue them.”

Pope Francis has made the war on climate change one of the hallmarks of his pontificate, never missing an opportunity to decry the evils of global warming and the human activities he believes are its root cause.

Francis was the first pope in history to write an encyclical letter, called Laudato Si, on the topic of care for the environment, in which he declared that the earth “is beginning to look more and more like an immense pile of filth” as “once beautiful landscapes are now covered with rubbish.”

He also identified the destruction of “biological diversity” and the degradation of the integrity of the earth “by causing changes in its climate” as “sins.”

Last November, Francis declared that humanity is undergoing a “climate emergency,” while denouncing skepticism toward man-made climate change as a “perverse” attitude that endangers the world.

“We need a conversation that unites us all, because the environmental challenge we are experiencing, and its human roots, affects us all,” Francis said.

Four “perverse” attitudes that obstruct the quest for concrete solutions to the problem of climate change “range from denial of the problem to indifference, nonchalant resignation, or blind trust in technical solutions,” he said.

In July, the pontiff said that “radical change” in human behavior is needed to beat global warming while calling on mankind to hear “the increasingly desperate cries of the earth.”

Immediate action is needed to save the planet from being reduced to “rubble,” he said.

The pope emphasized the “urgent need” for an “ecological conversion” as well as “concrete steps to save the planet.”

Our planet “needs urgently to be repaired and secured for a sustainable future,” the pope warned.

Pope Francis has publicly proclaimed his belief that “wars and climate change” are the root causes of world hunger and mass migration.

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