This brings the South Korean in line with the groundswell of opinion ahead of the COP16 talks, which will take place from November 29 to December 10.
Ban said at a UN press conference: "We need to be practical and realistic.
"It may be the case that we may not be able to have that comprehensive binding agreement in Cancun."
The secretary general did identify areas of "real progress", such as financing poor countries to tackle climate change.
He
