The secret deal has been proposed by the Danes, who are in charge of the conference, with some support from Australia and Mexico.
The two-day old UN summit went into a frenzy when the deal was leaked to the Guardian newspaper on Tuesday. That's because some poorer countries think the deal is too soft on rich countries, and they have threatened to turn their backs on the negotiations - rendering the summit of 192 countries a failure.
The 13-page document aims to limit global warming to two degrees, which means Australia would have to cut greenhouse gas emissions by 25 per cent by 2020.
It says rich countries would have to cut emissions by 80 per cent by 2050 - that's more than Australia is promising. And rich countries would have to find $US10 billion ($A11 billion) a year right away to help poor countries tackle climate change.
The deal is more green than past proposals, but it's not green enough for poor countries, who think it would let rich countries off the hook on climate change. They're worried that the deal seems to ditch the old climate treaty, the Kyoto protocol, which made rich countries cut their emissions. And China is worried because the deal would insist on international verification of countries' greenhouse gas emissions - a sovereignty issue