With not much time left, talks are deadlocked in Copenhagen. As a result, the heavy artillery is being hauled out with world leaders like Chinese Prime Minister Wen Jiabao, Us president Barack Obama, German Chancellor Angela Merkel, UK Prime Minister Gordon Brown, Brazilian President Luiz Inacio Lula de Silva and Iranian President Mahmoud Ahmadinejad set to descend on Copenhagen.

It's not looking good and China now says it sees no chance of getting any sort of deal. The closest thing we can get, it says, is some sort of political declaration.

If that's the best, everyone will be hoping that the document could be used as the basis for negotiating some sort of treaty further down the track. Don't hold your breath.

As British Prime Minister Gordon Brown told the BBC: "If you don't get an agreement this week, people will doubt whether you can get an agreement at all."

What that means is that leaders will have to get some sort of agreement that will commit everyone to striking a treaty later next year. If they fail to do at least that, Copenhagen will have been a complete waste of time. And ultimately, it would result in disaster.