LEXINGTON -- Special Masses are celebrated in Catholic churches throughout the world marking the Season of Creation, Sept. 1 to Oct. 4, the feast of St. Francis of Assisi.

The Masses, centered around Pope Francis's 2015 encyclical "Laudato si' -- On the Care for Our Common Home," are meant to encourage all Christians to care for the Earth and do their best to mitigate global climate change.

The Archdiocese of Boston's fourth annual Mass of Creation was celebrated by Vicar General Bishop Mark O'Connell at Sacred Heart Parish in Lexington on Sept. 14. The Eucharist at the Mass was whole-wheat unleavened bread baked at the Paulist Center in Boston.

"It was made by human hands, not a machine," said Fran Ludwig, co-chair of the Boston Catholic Climate Movement. "We wanted to work with human hands. It's more of a direct connection to the Earth if you can actually see that it's made out of wheat."

The Boston Catholic Climate Movement, founded in 2016, is one of thousands of groups in the global Laudato Si' movement.

In her remarks to the gathering before the Mass, Ludwig acknowledged the Massachusetts and Pawtucket tribes who first inhabited the land that came to be known as Lexington.

"They cared for the land for so many years in stewardship," she said, "they gave their gratitude to the Creator, and they also considered their kinship with the rest of nature. These are qualities that we are now thinking we need to emulate in this world today."

In his homily, Bishop O'Connell said that the words of "Laudato Si'" are not meant to be a political statement, but are rather "just the truth of our situation." He added that climate change is not viewed as a divisive political issue in Latin America the way it is in the U.S.

"They just think of climate change and the care for our planet as obvious," he said.

Pope Francis, Bishop O'Connell said, "takes the politics out of" climate change, and that Catholics in the U.S. should do the same.

"In our wonderful country, sometimes we mix up the obvious with the political," he said.He added that climate change should not be looked at as a "left-wing" or "right-wing" issue, but as a reality that should be addressed in a nonpolitical way."We should talk about our Earth and eventually bring up that we need to care for it," he said. "This is my hope and prayer for this particular movement in our archdiocese. That we start small, like Jesus did."

He said that the success of the Catholic environmental movement is not based on short-term involvement but on lasting impact, giving lifelong church attendance as an example.

If 20 people come to an environmental concern meeting, he said, "great! Twenty people who want to save the world. Beautiful!"

He also advised that Catholic environmental activists must be humble and pray for those who disagree, "rather than trying to fight back like a troll on the internet."

After Mass, the Boston Catholic Climate Movement hosted an informative reception in the parish center. Inside, there was a cardboard cutout of Pope Francis, with a speech bubble reading "Let's take care of our common home and all the people in it."

On a table next to the cutout was a petition urging the Massachusetts State Legislature to enact a climate bill, and books and pamphlets with information about climate change and Laudato Si'. The flowers that decorated the tables were saved from a local Trader Joe's that would have thrown them away. Almost all waste at the reception could be recycled or composted, even the plastic cups.

Deacon Tim Donohue, diocesan director of Catholic Relief Services, encouraged the assembly to make their concerns about climate change known to those who represent them in government.

"We live in a democracy where your voice is very, very important," he said. "And if you feel strongly about an issue, strongly enough to give up one of the nicest days of the year to be here, then you probably feel strongly enough to call the people that you are paying to represent you and tell them what you think."

He said that when calling representatives, it's best to research the issue beforehand, be friendly, and let them know you're part of a larger community of like-minded individuals.

"You have a lot of friends, and you can use that to your advantage to make a point," he said. "So if we don't say anything, we're abdicating our right to have a say."

Like parables in the Gospel, he said, environmental advocates should use stories of how they, their families, and their neighborhoods are caring for creation. These stories will inspire others to follow the example.

"We're trying hard to light a fire here in the archdiocese to talk more about creation," he said.