During his first prepared remarks in the United States, Pope Francis made a strong pitch for battling climate change, calling the present a "critical moment in history."
Speaking to President Obama and the crowds on the South Lawn of the White House, the pope said that the warming planet "demands on our part a serious and responsible recognition" of how this affects "our children [and] the millions of people living under a system which has overlooked them."
He continued, "Mr. President, I find it encouraging that you are proposing an initiative for reducing air pollution. Accepting the urgency, it seems clear to me also that climate change is a problem which can no longer be left to a future generation.”
The pontiff quoted his own encyclical on the environment, a papal document released earlier this year to global attention. In it, the pope called for a bold cultural revolution to correct what he calls the "structurally perverse" economic system of the rich exploiting the poor and destroying the planet.
"When it comes to the care of our common home, we are living at a critical moment of history," he said Wednesday. "We still have time to make the changes needed to bring about a 'sustainable and integral development, for we know that things can change,' " he said, quoting his encyclical.
"To use a telling phrase of the Reverend Martin Luther King, we can say that we have defaulted on a promissory note, and now is the time to honor it," Francis added, paraphrasing a line from the famous "I have a dream" speech.
During his trip to South America this summer, the pope highlighted the tensions between environment, business, and the plight of the poor in Ecuador. He appealed for better care of the Amazon rain forest and the indigenous people who live within it.
Not all American Catholics have joined Pope Francis's climate action campaign. Some US Catholic churches are leasing out their lands for drilling by oil and gas companies, despite the Pope's repeated calls to reduce fossil fuel use in order to combat climate change.
Climate change remains a hotly divisive issue in US politics. Climate change denier Rep. Paul Gosar (R) of Arizona has said he will boycott an address by Pope Francis to Congress on Thursday in protest of the pontiff's climate activism.
Last month, prominent Muslim scholars echoed the pope's call for climate action by asking world leaders to phase out their use of fossil fuels and called on Muslims to treat action on global warming as a religious duty.
On Wednesday, the pope reminded his secular audience of the theological roots of his environmental activism.
"We know by faith that the Creator does not abandon us; He never forsakes his loving plan or repents of having created us," he said. "As Christians inspired by this certainty, we wish to commit ourselves to the conscious and responsible care of our common home."