It is a big scale-back from the grand hopes of a couple of years ago, when the journey started down the road from Bali, but probably inevitable when individual national interests are competing with a more amorphous global problem.

Even so, Kevin Rudd has considerable incentive to do a domestic deal.

He is one of a small number of "friends of the chair" and will be at the December Copenhagen conference.

To have something tangible would be a boost for him.

The Government gives every impression of being serious about a deal on its legislation.

The question is: how serious?

The weekend concession on agriculture is important but not enough for an agreement, and not the hardest thing for Rudd to give.

Agricultural emissions were to be considered in 2013, and their possible inclusion in the scheme in 2015 was always going to present problems, so Rudd may have done himself a favour as well as the Opposition.

Even with this concession, there is still a significant gap between the two sides as crunch time comes.

The word from Malcolm Turnbull's quarter has been that if Labor came to the party on agriculture and excluded the "fugitive" emissions from coal mining, agreement could be on the cards.

Whether that would be enough for his truculent party room is another matter.

And what should we make of the Government announcing its concession on agriculture while the talks continue?

This can be seen as a sign of good faith. But Opposition negotiator Ian Macfarlane is more inclined to view it as a Government tactic, and believes it makes things harder for him with the party room.

While Rudd is hoping for his legislation, if he can't get it, he will play hard politically, shifting much of the blame to Turnbull for the failure to nail down a degree of bipartisanship.