WASHINGTON (CNS)—Carrying banners and signs with quotes from Pope Francis’ encyclical “Laudato Si’,” hundreds of Catholics joined the People’s Climate March to call for moral and prayerful action to protect creation.

On a sweltering day that reinforced the message about the need to respond to climate change—the 91-degree temperature at 3 p.m. April 29 tied a 43-year-old Washington record for the date—many in the Catholic contingent said they felt they had a moral obligation to witness in the streets.

“We march for our grandchildren. Stop global warming,” read one sign propped up in the back of St. Dominic Church in Washington, where about 300 people gathered before the march for Mass celebrated by Dominican Father Hyacinth Marie Cordell, the parish’s parochial vicar.

“The Vatican is solar. What about US?” read another. “We resist, we build, we rise,” read a sign from St. Francis and Therese Catholic Worker Community in Worcester, Massachusetts.

Underlying the messages on the signs and banners were people who shared a heartfelt concern to carry out Pope Francis’ call in his 2015 encyclical to live responsibly with the planet, remember the needs of others around the world and to reduce consumption and energy usage for the sake of God’s creation.

They also wanted to send a message to President Donald Trump that his policies on the environment and energy development do not follow the pontiff’s call to protect Earth.

The 300 people at the Mass heard Father Cordell call for an “ecological conversion” during his homily. He said each person must act in any way possible to protect God’s creation: reducing energy usage; limiting waste; choosing carpooling or biking and walking more; and buying less.

“We can learn increasingly to act not only with our own good and convenience in mind, but above all to think and choose according to what is best for all, especially for the poor and for future generations,” the Dominican said. “This ecological conversion calls us to self-examination, to make an inventory of our lives and habits so that we can learn to be better stewards of our common home and its resources, which are meant for the good of all.”

He said such steps require a revolution of the heart, as Pope Francis has called each person to undertake. He described it as a “change toward responsibility and virtue, a transition to thinking about the common good, future generations, the poor, other living beings, God’s glory and the environment in all of our decisions instead of thinking only in terms of a short-term, fleeting and superficial good or convenience for ourselves.”

March organizers said the event had been planned as a follow-up to the September 2014 People’s Climate March in New York City before Trump’s election in November. The April 29 march was led by indigenous people who already are facing disrupted lives as the climate warms and causes drought and rising ocean levels.

The march kicked off less than 48 hours after the Environmental Protection Agency began to revamp its website, taking down pages devoted to climate science. The agency said in a statement late April 28 that the information was “under review.”

Some of the Catholic marchers, a multicultural mix of young and old, families, and clergy, religious and laity, said they never had been involved in such a massive event, but that it was time to put their faith into action.

Atlanta environmentalist Susan M. Varlamoff took the Atlanta Archdiocese’s Catholic sustainability plan to the national march, using the cover of the Archdiocesan Action Plan as a sign, which drew a lot of attention.

In an email, she said, “What a day we had … marching in D.C. with people of all faiths, the indigenous people, scientists, the environmental nonprofits and children and their parents. Two hundred thousand strong we filled Pennsylvania Avenue. In the faith community, Catholics ruled with their numbers and signs. There were giant signs with Pope Francis’ quotes from Laudato Si’.”

She said that her sign, made from the front cover of the “Laudato Si’ Action Plan for the Archdiocese of Atlanta,” was noticed by many.

“People from all over the country came up to me to say they had read it.”

Along the march route on Pennsylvania Avenue from the Capitol to the White House, Nancy Lorence, a member of St. Francis Xavier Parish in New York City, said personal actions are crucial if people of faith are going to make a difference. She carried a colorful cardboard sunflower on a short stick that read, “Catholics 4 the EPA,” one of 45 similar signs that she and others making the trip had made.

“We feel like ‘Laudato Si’’ calls us to be in the streets, as Pope Francis says, and be active on the social justice issues and climate change,” Lorence told CNS.