VATICAN CITY (Reuters) - Environmentalists and aid agencies urged executives of the world’s top oil companies attending a Vatican conference on climate change on Friday to heed Pope Francis’s warnings about global warming.

Pope Francis arrives to lead the Wednesday general audience in Saint Peter's square at the Vatican, May 30, 2018. REUTERS/Max Rossi

Pope Francis, who wrote a major document on protecting the environment from global warming in 2015, will address the some 40 participants - including leading oil and gas executives and major industry investors - on Saturday.

The oil and gas industry has come under growing pressure from investors and activists to play a bigger role in reducing greenhouse gas emissions to meet goals set out in a 2015 climate agreement signed in Paris.

Companies are betting on increased demand for gas, the least polluting fossil fuel, and to a lesser extent on renewable power such as wind and solar to meet global targets of net zero emissions by the end of the century.

The Vatican has been tight-lipped about the closed-door event. But a Vatican source said the heads or senior executives of companies including ExxonMobil, Eni, BP, Royal Dutch Shell, Norway’s Equinor and Pemex were expected.

“Oil CEOs would do well to find common cause with the pope and ensure that their skilled staff and deep balance sheets are deployed to ensure that business is a force for good,” said Nigel Topping, head of We Mean Business, a non-profit coalition which works with businesses to promote action on climate change.

As severe weather events hit least developed countries hardest, many investors were demanding that companies take heed of the Paris targets, he told Reuters.

The conference, titled “Energy Transition and Care for Our Common Home”, is being held in the Pontifical Academy of Sciences, housed in a secluded 16th century villa in the Vatican gardens.

“If energy companies are serious about caring for our common home, they need to take the pope’s advice and hurry up with shifting their priorities – and therefore their money – from fossil fuels to renewables,” Neil Thorns, director of advocacy at Catholic aid agency CAFOD in London, said in a statement.

Groups such as CAFOD or We Mean Business are not taking part in the meeting, which is exclusively for oil executives and investors.

The participants will hear talks by top Vatican officials including Cardinal Peter Turkson, head of the Vatican’s department on promoting human development, who is a firm backer of the need to stem global warming.

In the 2015 encyclical, called “Laudato Si (Praise Be), On the Care of Our Common Home”, Francis, the first pope from a developing nation, called for policies to drastically reduce polluting gases, saying technology based on fossil fuels “needs to be progressively replaced without delay.”

Eldar Saetre, CEO of Norwegian oil firm Equinor, which changed its name from Statoil last month as part of a campaign to broaden away from its roots as an oil producer, is attending.

“We look forward to the dialogue, and the opportunity to discuss how we can address climate change and opportunities in the energy transition,” Equinor spokesman Baard Glad Pedersen said.