Climate change poses a threat to the lives of people in the world’s poorest communities, the Queen has told a meeting of hundreds of Anglican bishops.

In a letter to the 650 members of the clergy gathering from across the world at the Lambeth Conference, the Queen warned “those less able to adapt and adjust” were most at risk from environmental collapse.

“Now, as so often in the past, you have convened during a period of immense challenge for bishops, clergy and lay people around the world, with many of you serving in places of suffering, conflict and trauma,” she said.

We also live in a time when the effects of climate change are threatening the lives and livelihoods of many people and communities, not least the poorest

“It is of comfort to me that you do so in the strength of God.

“We also live in a time when the effects of climate change are threatening the lives and livelihoods of many people and communities, not least the poorest and those less able to adapt and adjust.”

The Queen added that the environment was “a cause close to the heart” of her late husband Prince Philip, and his interest in the field had been “carried on by the Prince of Wales and the Duke of Cambridge”.

The Lambeth Conference of Anglican bishops is convened by the Archbishop of Canterbury once every 10 years. It is taking place at the University of Kent, Canterbury Cathedral and Lambeth Palace between July 26 and August 8.

Bishops designated Wednesday as a day of prayer, fellowship and reflection on the themes of the environment and sustainable development.

The day includes the launch of the Communion Forest, a worldwide environmental programme to include tree planting, the creation of wetlands and coastal restoration projects by Anglican provinces, dioceses and churches across the world.

The Queen, who is Supreme Governor of the Church of England, also said in her welcome message: “It is with great pleasure that I send my warm greetings as you continue your meeting in the fifteenth Lambeth Conference.

“As we all emerge from the pandemic, I know that the Conference is taking place at a time of great need for the love of God – both in word and deed.”

The Queen’s message comes after the Archbishop of Canterbury Justin Welby confirmed that “validity” of Resolution 1.10 from the 1998 Lambeth Conference — which affirmed that marriage was “between a man and a woman”, and that same-sex relationships were unscriptural — is “not in doubt”.

In a letter to Anglican bishops written on Tuesday, he said: “I write therefore to affirm that the validity of the resolution passed at the Lambeth Conference 1998, 1.10, is not in doubt and that whole resolution is still in existence.

“Indeed the Call on Human Dignity made clear this is the case, as the resolution is quoted from three times in the paragraph 2.3 of the Call on Human Dignity.”

“The Call states that many Provinces — and I think we need to acknowledge it is the majority — continue to affirm that same-gender marriage is not permissible.

“The Call also states that other Provinces have blessed and welcomed same sex union/marriage, after careful theological reflection and a process of reception.

“In that way, the Call states the reality of life in the Communion today. There is no mention of sanctions, or exclusion, in 1.10 1998. There is much mention of pastoral care. We have a plurality of views.

“As Lambeth 1.10 also states: ‘All baptised, believing and faithful persons, regardless of sexual orientation are full members of the Body of Christ’ and to be welcomed, cared for and treated with respect (1.10, 1998).”

Speaking at the conference on Tuesday, the Archbishop of Canterbury added that he could not and would not punish churches for conducting gay marriages.

He said: “I neither have, nor do I seek, the authority to discipline or exclude a church of the Anglican Communion. I will not do so.”