Pope Francis has urged world leaders to take “radical decisions” at next week’s global environmental summit in a special message recorded for BBC Radio 4’s Thought for the Day.

Leaders attending the Cop26 conference in Glasgow must offer “concrete hope to future generations”, the pontiff said.

Francis is not attending the summit, despite earlier suggestions that he would fly in for a brief appearance to reinforce the significance of the event. His message was recorded in Italian and lasted almost five minutes. It was broadcast on Friday morning with a voiceover in English.

He said: “Climate change and the Covid-19 pandemic have exposed our deep vulnerability and raised numerous doubts and concerns about our economic systems and the way we organise our societies.

“We have lost our sense of security, and are experiencing a sense of powerlessness and loss of control over our lives. We find ourselves increasingly frail and even fearful.”

A succession of crises relating to healthcare, the environment, food supplies and the economy were “profoundly interconnected”, he said. “They also forecast a perfect storm that could rupture the bonds holding our society together.”

Every crisis called for “vision, the ability to formulate plans and put them rapidly into action, to rethink the future of the world, our common home, and to reassess our common purpose. These crises present us with the need to take decisions, radical decisions that are not always easy. At the same time, moments of difficulty like these also present opportunities, opportunities that we must not waste.

“We can confront these crises by retreating into isolationism, protectionism and exploitation. Or we can see in them a real chance for change, a genuine moment of conversion, and not simply in a spiritual sense.”

This could only be pursued through “a renewed sense of shared responsibility for our world, and an effective solidarity based on justice, a sense of our common destiny and a recognition of the unity of our human family in God’s plan for the world”.

Political decision-makers meeting at Cop26 “are urgently summoned to provide effective responses to the present ecological crisis and in this way to offer concrete hope to future generations. And it is worth repeating that each of us – whoever and wherever we may be – can play our own part in changing our collective response to the unprecedented threat of climate change and the degradation of our common home.”

Later on Friday, the pope was due to receive Joe Biden at the Vatican. The pair will discuss the climate emergency, an issue that Francis has put at the heart of his papacy since 2013.

On Saturday, leaders from the world’s leading economies will meet in Rome for the G20 summit to discuss the Covid pandemic, climate change, the global energy crisis and other major challenges.

A draft G20 communique says leaders will pledge to take urgent steps to reach the goal of limiting global warming to 1.5C.

The US president, a devout Catholic who carries a rosary and attends mass most Sundays, last met the pope in 2016 during a papal visit to the US. After Biden’s election victory almost a year ago, Francis was one of the first world leaders to congratulate the president-elect.

In 2015, Francis published an encyclical on the environment that was an ambitious call to the world population to take urgent action to avert a climate catastrophe. Laudato Si’ criticised consumerism and the lack of effective action from world leaders.