Former Archbishop of Canterbury, Dr Rowan Williams, led protesters over the weekend in praying for the world's leaders to take tougher action on climate change.
The prayer vigil brought Christians together outside St Paul's Cathedral in London on Palm Sunday to mark the start of the Extinction Rebellion's week of peaceful climate protests.
The vigil was organised by Christian Climate Action (CCA), a community of Christians committed to acts of public witness and non-violent direct action to challenge climate breakdown.
In London, Extinction Rebellion campaigners will be blocking roads, hosting art installations and putting on protest performances.
Dr Williams said CCA was responding to the scale of the environmental crisis facing the world.
He said: "Christians are called by God to show to the world what the divine image looks like - the image of a divine creator who brought the world to birth, called it good, and summoned human beings to reflect this divine care and delight through their own work in the world, animated by the gift of Christ's Spirit.
"Christian Climate Action seeks to respond to that summons; in the face of impending environmental crisis, we need to encourage one another to grow more fully into the joyful responsibility we are made for."
Churches around London are supporting the Extinction Rebellion's week of action by opening up their facilities as accommodation for protesters.
Others will ring their church bells 12 times to symbolise the warning from scientists that the world has just 12 years to avert a climate catastrophe by limiting global warming to 1.5C.
In Marble Arch, in the heart of the capital, clergy will be taking part in environmental stations of the cross and foot-washing to support tired protesters.
Holly-Anna Petersen, a member of CCA who attends St Luke's Church in North London, said that in spite of years of protests and petitions, she was "frustrated that decision-makers still aren't creating the change needed".
"The desperation and suffering that climate change is causing around the world breaks my heart," she said.
"People are fighting for their very survival. This is not okay, this is an emergency and must be treated like one.
"In the UK, people hear the science of climate change and are scared for their children and grandchildren."
She said, however, that her Christian faith gave her hope for the future.
"My hope does not come from blindly repeating the same old strategies which have failed us," she said.
"It comes from seeing ordinary people responding prayerfully to the challenge of climate breakdown - having the bravery to work through the anxieties that we each have and taking the action required."
CCA member Fr Martin Newell, from Birmingham, said he was prepared to go to prison if it meant that more would be done to stem harmful climate change.
"As Christians, we are called to do all we can to stand up against injustice and for our common home," he said.
"I don't want to be arrested or go to prison, but if that is what it means to be faithful in the face of climate breakdown then I am willing do so, just as Jesus did after he turned over the tables in the temple.
"We know Christians are called to a sacrificial faith and that we are each called to do all that we can."
He added that more needed to be done at the government level to address climate change.
"Changing our light bulbs is not going to cut it. We need dramatic changes in government policy if we stand any chance of saving God's beautiful creation and the humanity that He loves," he said.
"Non-violent direct action is a strategy that can bring the political earthquake that is needed, and so like many faithful Christians before me, this is my response."