Pope Francis on Saturday urged people to pull investments from companies that are not committed to protecting the environment, adding his voice to calls for the economic model that emerges from the coronavirus pandemic to be a sustainable one.

Francis spoke in a video message for an online event called "Countdown Global Launch, A Call to Action on Climate Change."

"Science tells us, every day with more precision, that we need to act urgently ... if we are to have any hope of avoiding radical and catastrophic climate change," he said.

The pope listed three action points: better education about the environment, sustainable agriculture and access to clean water, and a transition away from fossil fuels.

"One way to encourage this change is to lead companies towards the urgent need to commit to the integral care of our common home, excluding from investments companies that do not meet (these) parameters ... and rewarding those that (do)," he said.

He said the pandemic had made the need to address the climate crisis and related social problems even more pressing.

"The current economic system is unsustainable. We are faced with a moral imperative ... to rethink many things," he said, listing means of production, consumerism, waste, indifference to the poor, and harmful energy sources.

In June, a Vatican document urged Catholics to disinvest from the armaments and fossil fuel industries and to monitor companies in sectors such as mining for possible damage to the environment.

Other speakers and activists at the online event included actress Jane Fonda, Britain's Prince William, former U.S. Vice-President Al Gore, and European Commission President Ursula von der Leyen.