"We have to start and struggle again, and it is a harsh way in front of us," Msgr. Sayer told Catholic News Service minutes after the Mass at the 16th-century church Dec. 13, the day after the climate conference produced its final agreement.

He and other Catholic groups varied as to which of their summit ambitions had been met and which had not, but all of them contended that their struggle to save the environment was just beginning, and they called for further mobilization.

The same day, after reciting the Angelus at the Vatican, Pope Francis said the agreement required a "concerted commitment" to continue forward.

"In the hopes that it guarantees particular attention to the most vulnerable populations, I urge the entire international community to continue the path undertaken with care, in a sign of solidarity that becomes ever more constructive," Pope Francis said.

The conference in the Paris suburb of Le Bourget ran one day longer than expected in an effort to produce an agreement. Catholic activists had lobbied for the inclusion of human rights protections and lowering the threshold for the earth's temperatures to be more in line with scientific research. They also advocated for adequate financing for poor countries to adapt to cleaner energy, and the phasing out of fossil fuels.

Bernd Nilles, who served on the Vatican's official delegation to the climate change conference, said because the issue of human rights for indigenous and other vulnerable people had made it only to the preamble and not in the new accord's binding body, some nations might say "'Yes, we have to reduce greenhouse gas emissions, so we build major hydroelectric, or major dams and we move all these people.'"

"It will give us a lot of headaches in the future because governments now can take climate action by ignoring the local population," Nilles told Catholic News Service at Saint-Merry.

Genevieve Talbot, who lobbied at the Paris talks for the Canadian Catholic organization Development and Peace, concurred that "the human rights aspect should have been included in the operative part" of the text, as well as the issue of food security.

"In fact in the operative part, we no longer mention food security, but rather food production, which is quite worrisome: It means that in order to ensure food security, (greenhouse gas) emission can increase," Talbot told CNS in an email from Montreal, where she returned after the conference.

Michel Roy, secretary-general of Caritas Internationalis, said that despite the new accord's "essential connection between climate change, poverty eradication and equitable access to sustainable development," it was "regrettable that human rights are not at the core," adding "we should avoid vested interests prevailing over the common good."

On another key issue -- what the highest threshold should be for the earth's heat -- some Catholic groups heralded what they saw as a major feat. Throughout the two-week conference, the groups had referred to scientific studies showing that limiting global warming to an increase of 1.5 degrees Celsius would benefit millions of the world's people by reducing adverse weather disasters, such as floods, drought, typhoons and rising sea levels.

The accord's "long-term goal is well below 2 degrees Celsius, which is a great step," said Talbot.

Talbot and Chloe Schwabe, who lobbied for Maryknoll Office of Global Concerns at the U.N. conference, lamented a lack of guidelines or enforcement mechanisms in the agreement to ensure nations would comply with the new temperature thresholds laid out only as aspirations in the new agreement.

"The 1.5 Celsius degree temperature rise target will only help achieving climate justice if all countries do their fair share," said Talbot.

"Ensuring there is enough ambition to stay below 2 degrees and meet the overall 1.5 goal will be a challenge," Schwabe added.

Another long-term goal of Catholic and other activists in Paris -- to wean the world off fossil fuels, whose extraction and burning are responsible for the global warming that the summit ostensibly aimed to curb -- was not met, said Nilles, secretary-general of the international Catholic development coalition CIDSE, an alliance Catholic development agencies based in Brussels,.

The final text of the accord set no clear limits on greenhouse gas-emitting fuels, said Nilles, something he blamed on several big industry countries, including Saudi Arabia and the United States.

"I was a member of the Holy See delegation, so I could clearly see how Saudi Arabia and others were working really hard to undermine a strong agreement because by phasing out fossil fuels, we take their blood line away," he said.

He expressed disappointment that the financing measures that the accord laid out to help developing nations adopt cleaner sources of energy were "built on hope that industries and companies will invest," and not enough on public funds.

"So it is not that we will take public money in our hands and we will help these vulnerable countries," he said.

Schwabe agreed that the climate accord's lack of public financing for adaptation to alternative fuels was a problem.

"Adaptation is already necessary for some countries and vulnerable communities," she said. "We must make sure there is enough money in place to assist communities on the front lines of climate change to adapt to the impacts of climate change we already witness."

In light of the Paris agreement, and ahead of U.N. climate talks scheduled for next year in Morocco, Catholic groups said further mobilization on a widespread scale would continue to be vital.

"What we have on the table is not sufficient," Msgr. Sayer said of the new climate accord in general.

"We have to start immediately to put all our forces together from the civil society, from the politicians, from the officials in the companies and also from the shareholders -- they have not to think about the short-term profit, but about the long term," he said. He noted with a smile that he was headed to Germany "to further advocate for climate justice at home."

"Everybody here is super tired and yeah, the team deserves to have a break," added Nilles, who said he had spent the day after the accord was announced demonstrating for climate justice along with thousands of other activists on Paris streets.

"But then we must come with renewed energy, to continue mobilizing for climate justice. This is not the end," he said.