Tutu was speaking at a World Aids Day event, hosted by the Desmond Tutu HIV Foundation, in Masiphumelele township, near Cape Town yesterday.

He cautioned the foundation's main sponsor, oil company Chevron SA, about the effects of climate change.

"I've just come back from Durban and I have to have two sides of my face because we really have to take the challenges of climate change seriously," said Tutu.

"We might be able to defeat Aids and discover that we are getting ourselves fried or are drowning."

He recently spoke at the global climate change talks, COP17, now under way in Durban.

Tutu said the fact that "all of us want to see this country do well" gives him hope and that South Africa was doing well in the battle against Aids.

"We have made significant inroads. There was a time when we were overwhelmed and thought we would never see the end of the road but now it's clear that we can in fact get to the point where we have a generation not infected by Aids.

"It is possible, and I want to pay tribute to all of the wonderful people who have worked and are reducing the mountain to something manageable," Tutu said.

He urged the young to take the lead in the fight against Aids and climate change.

He said young people especially should get tested for Aids.

The theme for World Aids Day is "Getting to Zero" - which translates to no new HIV infections, zero discrimination and zero Aids-related deaths.