AS THE world gets ready for next week's expected publication of Pope Francis's encyclical on the environment, negotiators met in Bonn, Germany, to work on a global agreement to tackle climate change which is due to be struck in Paris later this year.

The intervention of the Pope has raised awareness of the global climate debate. The Archbishop of Cape Town, the Most Revd Thabo Makgoba, attended the summit for the first time.

He is co-ordinating the Anglican "Eco Bishops" initiative: a network of 20 leading Anglicans from around the world who are keen to provide a spiritual vision on a subject that is often left to economists, scientists, and politicians.

Archbishop Makgoba said that Christian leaders had an important part to play: "We meet millions of people without coercion every Sunday. They come every week to our churches and our house groups. We have a mandate, but not a short-term one like politicians. We are able to look long-term.

"We have a responsibility to shape God's people so they reflect the nature of God, which is love, hope, compassion, forgiveness, and inclusivity. We don't exist for ourselves: we exist for something greater."

At the talks in Bonn, climate sceptics were thin on the ground. But the Pope's impending contribution to the debate has drawn the ire of some, especially in the United States, where he will address Congress in September.

Rick Santorum, the Roman Catholic senator who is running for the Republican presidential nomination, recently called on the Pope to keep quiet on the issue. But he was rebuked this week by the Fox News host Chris Wallace, who, while noting that Pope Francis had a science degree, unlike Mr Santorum, asked: "I guess the question would be: if he shouldn't talk about it, should you?"

In the UK, the papal encyclical is likely to coincide with a mass lobby of Parliament. Thousands of people are being asked to travel to Westminster next Wednesday to speak to their MP about making climate change a priority.

As well as a rally, there will be an ecumenical service at which the Bishop of Salisbury, the Rt Revd Nick Holtam, will speak. The Bishop, who returned last week from Malawi, where he saw effects attributed to climate change, said: "The changing climate is affecting all of us, but is pressing hardest on those who are most vulnerable.

"As the Church, we are called to serve the world's poorest people; that's why we need to speak up and call our government to act now."

The lobby is being supported by the Climate Coalition, consisting of more than 100 organisations, including Christian Aid and the Salvation Army.

The UN summit in Paris later this year has started to inspire acts of solidarity among faith groups around the globe. In the vulnerable Pacific island of Vanuatu last week, the former climate-change commissioner for the Philippines, Yeb Sano, launched the Global People's Pilgrimage, on which people from every continent will walk to demonstrate their concern and call for a strong deal in Paris.

"In our common aspiration to confront the climate crisis, we cannot afford to say that we'll cross the bridge when we get there. We have to get there now," he said.

A sign that governments are starting to take the climate issue seriously was this week's meeting of G7 leaders. The communiqué made front-page headlines around the world when the leading industrial nations agreed to phase out fossil fuels by the end of the century.

Joe Ware is Church and Campaigns Journalist for Christian Aid.