Most of my memories of Copenhagen involve walking. Strongest of all are memories of following long, slow-paced marches from point A to distant B, sometimes hedged round by bristling police, sometimes alone in the dark afternoon.
Unlike most journalists, penned up in the daylight-free hole that was the press room at the Bella Centre, I was outside with the activists. The deal-making took place at a distance. We read up on it at the end of the day, or tossed rumours about as we walked around the city in the snow. At the end of the fortnight we all looked, unsurprised, at politicians on all sides, backing away with hands up, and saying: "It was him, it wasn't me!"
My favourite memory, however, doesn't involve any world leaders. It is of the moment when activists very briefly succeeded in their goal, on the Reclaim Power demonstration, of breaching the Bella and holding their own summit inside its walls. We had already been walking for four hours that day, meeting at 8am at a nearby railway station and then marching to the venue of the summit. To the south, across a small moat, lay the Bella Centre. Between the moat and the cops, success seemed pretty unlikely.
Suddenly, out of a cluster of demonstrators arose a column of people, running frantically with something on their heads . . . could it really be? It was! Under cover, they had blown up seven or eight Lilos and tied them together to form a makeshift bridge. They were heading for the moat, leaping over the fence to the north of it and down the bank. The Lilo-bridge snagged on the thick gorse - and then was out, launched into the moat.
Police were already beginning to gather on the other side; fairly quickly the dogs were brought along. Meanwhile the activists started to crawl out on the bridge. I have never been so full of admiration for anyone as the man at the front who crawled slowly but determinedly right to the other side to receive a faceful of pepper spray, before being taken away in handcuffs. It was brave, bonkers and extraordinary.
After I got home I had an argument with someone who claimed that the small African countries had sabotaged the deal. "Why didn't they sign up? They ruined it," he raged. I tried to explain that they were fighting for their lives. Why should they sign something that would cook their own continent for the sake of a face-saving "deal"? Like that Lilo-bridge, they would not give in to the inevitable.
And so it was with the activists, with the people trying to right the world at the "alternative summit" down at Klimaforum09. Much of the time it felt like a desperate rearguard action, out there in the snow with gigantic Danish police looming over you. But they'd rather go out feet first.
And it's for that reason we've got an interesting year coming up, I think. The activists may not have turned out in quite the numbers hoped for, but there were enough of them to make a lot of noise. They got to know each other better, formed links with groups and people from northern and southern hemispheres, and came away with convictions that had not been weakened by the snow, the darkness, the police, the endless walking. Bring it on, is what I keep on hearing. Bring it on.
Bibi van der Zee's column runs fortnightly
Next week: Mark Lynas