"The destruction of the earth environment is the human rights challenge of our time," Tutu said.
Uploaded to YouTube by The Desmond & Leah Tutu Legacy Foundation, the video addressed rising greenhouse gas emissions and climate degradation which wreak havoc primarily on the poor and underprivileged.
"Time is running out," Tutu urged.
Tutu called the summit a "decisive moment in the struggle to maintain God's Earth." But the UN alone can only do so much, Tutu said. Independent governments and world leaders must also step up to the challenge to protect the environment for future generations.
The archbishop wrote an article for The Guardian in May saying, "We need an apartheid-style boycott to save the planet."
There is no excuse not to prioritize the earth, Tutu wrote, for climate change affects us all. He encouraged colleges, companies and faith organizations to divest from fossil fuels, as the World Council of Churches has done.
"To serve as custodians of creation is not an empty title," Tutu wrote. "It requires that we act, and with all the urgency this dire situation demands."