Failure to do so would send a direct message of contempt to poorer nations and people, who cannot afford the costs of mitigating the impacts of increasing temperatures, Tutu said in a statement.

"It will trigger unprecedented economic and refugee crises, and dramatically deepen global insecurity," he said.

Almost 150 heads of state and government, including President Jacob Zuma, were expected to assemble for the 21st Conference of the Parties.

Tutu encouraged that the leaders draft a legally binding treaty to mitigate climate change, saying this would lead to an end to reckless consumption, exploitation and greed.

"Anything less than a legally enforceable treaty on carbon emissions will be to condemn our children from inheriting a disfigured world and a blighted human family," he said.

"It’s a simple equation, really. Agree on mechanisms to enforce adherence to environmental justice, or consciously embrace injustice and add fuel to the fire of human division and pain," he warned.

Tutu expressed strong support for sustainable technology, calling for a reduction in dependency of carbon fuels.

"Continuing to spend trillions of dollars searching for new oil, gas and coal reserves we will never be able to use, is a self-fulfilling prophecy of doom," he said.

"And that is why we say: Global warming is the human rights challenge of our time. If we do not address it, collectively, it can only mean we have decided that the rights of some members of the human family are more important than others," he said.

-News24.com