Pope Francis urged scientists to be in the vanguard of protecting the environment, in a speech critical of politicians yet to show "concrete will" in implementing global climate agreements.
The remarks at a symposium whose attendees included the British physicist Stephen Hawking, an avowed atheist, may have been directed at US President-elect Donald Trump.
Trump threatened to pull the United States out of the COP21 Paris Agreement, that binds countries to national pledges to reduce greenhouse gas emissions, during a bruising election campaign.
Francis said it had fallen to the scientific and Christian communities to join together "in the shared goal of protecting our common home, threatened as it is by ecological collapse."
Such an alliance was possible because both "work free of political, economic or ideological interests" albeit using different approaches.
In contrast, "international politics has reacted weakly – albeit with some praiseworthy exceptions – regarding the concrete will to seek the common good," he said.
"The submission of politics to a technology and an economy which seek profit above all else, is shown by the 'distraction' or delay in implementing global agreements on the environment," he added.
During the race for the White House, Trump repeatedly told crowds of rustbelt and southern voters -- factory workers, coal miners and oilmen among them -- that he would tear up climate agreements.
As far back as 2012 he had tweeted: "The concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive."
Since being elected, however, Trump has said he is "open minded" about whether to support global accords.
The Pope, who did not refer to Trump or any other politician by name, wrote a papal letter on the environment last year in which he said rapid action was needed to save the planet from ruin.