Leaders of the Catholic church in America took their "marching orders" from the pope's encyclical on Thursday, fanning out to Congress and the White House to push for action on climate change.

The high-level meetings offered a first glimpse of a vast and highly organised effort by the leadership of America's nearly 80 million Catholics to turn the pope's moral call for action into reality.

"It is our marching orders for advocacy," Joseph Kurtz, the president of the US Conference of Catholic Bishops and the Archbishop of Louisville, said. "It really brings about a new urgency for us."

Representatives of the US Conference of Catholic Bishops said they would hold two briefings for members of Congress on Thursday and visit the White House on Friday to promote and explain the pope's environmental message.

Those efforts will get a new injection of urgency, when the pope delivers a much-anticipated address to Congress during his visit to the US in September, church leaders said.