Christians are urging country leaders to agree to 'transformative action' on climate change when a major UN climate summit takes place this week.

COP24 is taking place in Katowice, Poland, from Sunday to renew the commitment countries made in Paris in 2015 to keep global temperature rises to 1.5C.

The World Council of Churches (WCC) said it was time for global solidarity and urgent action to support the communities that are already feeling the effects of climate change.

Rev Dr Olav Fykse Tveit, general secretary of the World Council of Churches, said UN member states needed to ramp up their climate pledges if the target of 1.5C is to be met.

'There is no more time to waste in short-term self-interestedness,' he said.

'Urgent adaptation and mitigation measures, transformation of economic systems, deep behavioural change, and supportive national and global policies and institutional arrangements are needed now to avoid potentially catastrophic consequences of climate change.

'In facing this existential challenge, hope lies in realizing that sustainability and justice are two sides of the same coin.'

The Lutheran World Federation (LWF) and ACT Alliance are making similar appeals. Rev Dr Martin Junge, LWF general secretary, said it was the responsibility of churches to advocate for climate justice.

'As people of faith we know well how God wants this world to be and what God wants for human beings and calls them to be in this world,' he said.

'Our message to the churches and to the world is that creation is not for sale. As churches we should focus on that vision and engage in action for climate justice.'

The LWF will be bringing its call for climate justice straight to COP24 with a delegation of seven young church members involved in climate advocacy from around the world.

'They are issuing a clear call to the current generation, for future generations. Because climate change won't disappear by declaring that it doesn't exist,' added Dr Junge.

Rudelmar Bueno de Faria, general secretary of ACT Alliance, said that the successful implementation of the Paris Agreement was hinging on the guidelines that are further developed at COP24.

He said it was important that world leaders meeting in Poland agree on an 'ambitious and just' implementation of the Paris Agreement 'rather than watering it down'.

'Our call for climate justice and climate action is urgent. We are faced with unprecedented crises,' he said.

'Communities and countries are losing their territories in the Pacific to rising sea levels.

'Floods and droughts are causing humanitarian emergencies in Asia and Africa.'

He voiced concern that developed countries are not keeping their promises of financial support for developing countries to implement climate adaptation and resilience strategies.

'We are also disappointed that there isn't adequate climate change finance, and so far it has not met the criteria of predictability, additionality and transparency,' he added.