The awful possibility, which spread a frisson of fear through the meeting rooms and negotiating huddles, was that instead of ending as scheduled last night, the conference was going to continue until today, or even tomorrow. Global warming, rising oceans, malaria epidemics and skin cancer suddenly paled into insignificance. Nothing, nothing, could be worse than another day of this.
Future generations may or may not look back on the Kyoto conference as a historic moment when the nations of the world put aside greed and self-interest for the sake of their unborn grandchildren. Those of us who were present will remember it for very different reasons - as a tedious, migraine-inducing waste of time, an orgy of dismal food, pompous rhetoric, short tempers, and bad jokes.
Several things have made the conference nearly unbearable, first among them its setting - the Kyoto International Conference Hall (Kich). Reports from Kyoto have all described the city as Japan's "ancient capital", a Shangri-la of temples, palaces and exotic beauties in exquisite kimono. The truth is that since COP3 opened 10 days ago very few delegates have stepped beyond the grey portals of the Kich, a modernist concrete spaceship, appropriately pronounced "kitsch". Instead of exploring the surrounding mountains, they have spent 10 days drinking cups of coffee and eating sandwiches containing cold pork cutlets (a Japanese favourite).
Kich is huge, but so is the conference and all week journalists, politicians and NGOs have trod on one another's toes with increasing grumpiness. John Prescott, the Deputy Prime Minister, lost his rag on Monday night after being kept waiting for an hour by the American delegation. Michael Meacher and several of his European counterparts narrowly escaped being crushed yesterday when a mob of cameramen almost knocked down a temporary cubicle on their heads.
Even the best-natured stunts have fallen victim to sense of humour failure. One green group mounted a wacky allegoric stunt involving members dressed as world leaders kicking around a ball representing the planet. But when an Italian journalist stole their globe, they called security and tried to have him chucked out.
It is one measure of the conference's awfulness that a meeting of the some of liveliest minds in the world has so far generated just one COP3 joke. Q. How many Americans does it take to change a light bulb? A. None. Free-market forces will change it all by themselves. Har-har-har.
If, like me, you failed to secure a hotel room the requisite three months before the conference your plight has been doubly wretched - 10 days dependent on the generosity of better-organised friends, with personal belongings scattered across various parts of the city, moving from place to place in unchanged shirt, reeking socks, and recycled underpants.
An average collection of conference literature fills one suitcase alone, but even the most disciplined delegates have been reduced to shambling bag ladies, bent double under the weight of recycled paper press releases.
It is not even as if this effort and expense has fulfilled expectations. The situation was drolly summed up the other day by Raul Estrada-Oyuela, the Argentine roly-poly who revels in the title of chairman, Committee of the Whole. Goaded to distraction by the possibility of an extended conference, one journalist pinned him down: what, he begged, was the final deadline for the conference.
Mr Estrada tipped his head to one side and leant into the microphone: "The deadline? It is the end of the world, no?"