Many of those taking part are from nations which are already bearing the brunt of climate change.
Piper Willie Park will open the service by leading a procession into the 12th century building, and later members of the clergy will walk to the tomb of St Mungo, the patron Saint of Glasgow, who was buried on the site in the 7th century.
Church leaders from Scotland have each been asked to invite young climate activists as guests.
Representatives from the Young Christian Climate Network (YCCN), a group who have completed a 1,200 mile relay to Glasgow will also be in the congregation.
Rev Dr Martin Johnstone, who is the COP26 Ambassador for Glasgow Churches Together, said: “It has been inspiring over the last week to meet and learn from passionate young people committed to climate justice and to spend time listening to the wisdom of people from some of the nations most impacted by climate change.
“It will be wonderful to have many of them at Sunday’s service.”
The sermon will be delivered by Rev Dr Susan Henry-Crowe, General Secretary of the General Board of Church and Society of the United Methodist Church, who will use Psalm 23 (The Lord’s My Shepherd) as her text.
As part of her reflection Dr Henry-Crowe will draw on three art installations which are in the Cathedral: ‘Returning and Into your Arms’ by James Pfaff; ‘I will sit with you and I will learn to listen’ by Gardner and Gardner; and ‘A Lament in Black Paint’ by I.D Campbell.
Dr Henry-Crowe said: “Our stories of faith acknowledge the stories of God’s goodness in creating our world.
“We know the stories of how it began and how exquisite it was.
“And we have a special responsibility to listen to those living closest to the earth and seas, indigenous communities – animals birds, fish.
“Do not pollute the waters.
“Return the habitation of your communities to clean and healthy spaces.”
There will be additional contributions from Bishop Bill Nolan, from the Catholic Church in Scotland, and Most Rev Mark Strange, Primus of the Scottish Episcopal Church.
Lord Wallace, the Moderator of the General Assembly of the Church of Scotland will give a Bible reading.
Other groups represented include representatives from the All Africa Conference of Churches, the Pacific Conference of Churches, the Anglican Communion, the Catholic Church, the Orthodox Church, the World Communion of Reformed Churches, the World Council of Churches, Eco-Congregation Scotland and the Scottish Church Leaders’ Forum.
Rev Mark Johnstone, who is the minister of Glasgow Cathedral, said: “Over the last week, we have welcomed the world to Glasgow.
“On Sunday, it will be wonderful to welcome people from many nations to Glasgow Cathedral, a place where people from all over the world have gathered for centuries to meet and to worship.”
The event, which is by invitation only, will begin at 4pm and will be live-streamed on the Glasgow Cathedral website.
A professional photographer will be distributing photographs to picture desks after the event. If you are particularly interested in receiving photographs please let Jane Bristow know by emailing firstname.lastname@example.org or phoning 07963633941.