A quiet bombshell on Copenhagen climate treaty?
All eyes are on New York today, for the latest political moves ahead of the make-or-break conference in Copenhagen in December seeking a global climate deal to replace the Kyoto Protocol.
And last night it looked as if Danish prime minister and host of the talks, Lars Løkke Rasmussen, was about to drop a quiet bombshell.
He was expected to make clear that he is no longer looking to Copenhagen to deliver a "treaty", that is a document with legally enforceable emissions cuts, but only "a political declaration" - an altogether different outcome.
But overnight reaction from European countries has now put a question mark over that, suggesting that he may now defer his announcement.
Downgrading from a treaty to a political declaration would be a bitterly disappointing result for those pinning their hopes on Copenhagen, despite all the warning signs that a meaningful deal looks perilously close to impossible.
Yet, a political declaration may still be worth having, if the detail is right.
If it includes a line committing countries to agreeing emissions cuts say by the middle of next year, then it may still be effective.
If not, then the politicians risk going home thinking they have achieved a deal, but one that proves empty and undermines the carbon price.
Granted, everything is still "in the balance" as the Miliband brothers put it two weeks ago.
And there are positive signs. Later on Tuesday, Chinese president Hu Jintao is expected to say enough on China's emissions plans that it can stake a claim to be leading the world.
At least that is the way his speech was trailed last night by the UN's senior climate negotiator, Yvo de Boer.
After all, someone has to fill the leadership vacuum.
President Barack Obama is struggling with his climate bill at home. This is in second place to getting healthcare reforms passed. And even if health goes well, and earns Obama political capital from unexpected success, hopes of formulating a meaningful US offer in time for Copenhagen - with real figures on emissions cuts - will remain on a knife-edge.
The problem is that all this "high-level" political activity has a downside as well as an upside.
If prime ministers and presidents get involved, then they can at least negotiate with real authority - without having to constantly "phone home". But they also bring their own staff, with the risk that they edge to one side the climate negotiators with knowledge of the detail that is needed for a deal to have an impact in the real world.
Because it is the real world that sets a time limit on these talks - and marks them out from other global discussions.
Leaders of the world's largest economies have accepted scientific advice that the increase in global average temperature above pre-industrial levels ought to stay below 2C - defining this as the threshold into dangerous climate change.
So success or failure at Copenhagen has one simple test - is the deal enough to secure that 2C limit?
If the talks fail, it gets tougher to fix the problem later, because climate scientists are now confident that for a reasonable chance of keeping temperature rise below 2C, the concentration of greenhouse gases should not go beyond 450ppm of carbon dioxide equivalent.
And to do this, they say, global carbon emissions must peak within the period 2015-2020 and decline rapidly after that.
Hence the race against time, and the need for the detail to be right.