Protesters are stepping up pressure as the climate talks teeter on the brink of failure [Reuters]

The word everyone was using when Wednesday began in Copenhagen was "crucial".

It was used about the important discussions in the hall and violent confrontations outside.

Outside, in the swirling snow, hundreds gathered close to the city centre.  Their intention was to march to the summit and the break into the talks.

But there was an underlying tension. They wanted to breach the police lines, and claim the meeting hall.

They said they wanted to create a people's assembly. The police weren't going to let that happen.

They set up a line outside the centre to push the demonstrators back. This led to violent confrontations.

Police used their batons to break up the crowd, they even used pepper spray.

No one managed to get through security.

The talks so far have produced little but disappointment [AFP]

This was a sign of the growing frustration with the politicians and the disappointment of the talks so far.

In the hall itself, a surprise resignation. Connie Hedgaard, the Danish President of this summit, delivered her resignation.

"Protocol" her spokeswoman said. "A simple acknowledgement of the need for the Danish prime minister to take control".

"The need for a political heavyweight to steer the discussions to a deal" said the whispers.

'Lifeboats'

And so in the hall they talked. They discussed the procedures, the need for discussion, the desperate need for agreement, but still there was none.

"I have the feeling of dread we are on the Titanic and we are sinking fast," he said.

"But we can't launch any lifeboats because a member of the crew has decided that we are not sinking and that we have to have informal consultations to decide if we are sinking or not".

One of the biggest sticking points remains finance; who pays what to whom and who gets cash to help fight climate change.

Economist Nicholas Stern wrote an influential report which warned the costs of doing something now would be much less than living with the consequences of a warming planet.

"What we talking about is not an enormous amount of money, but it could transform the planet," he told me.

"It would be a more dramatic development than electricity or the railways. The world can't afford to do nothing."

'Capitalism obstacle'

Bolivia's Evo Morales says rich nations are scuppering chances for a deal [Reuters]

Evo Morales, the Bolivian president, is here. His population is at increasing threat of climate warming.

"The white poncho has disappeared from the mountains and so our water source is disappearing", he told me.

He has watched the events here over the last 10 days with increasing concern. He says he does not believe there will be a deal and he lays the blame with the world's richest countries, increasing industrialisation and the pursuit of profit.

"The principle obstacle to combating climate change is capitalism. Until we put an end to capitalism, it will continue to be a big obstacle for life and humanity." 
 
And now everyone waits for all the leaders to arrive, particularly those from the US and China.

Many believe the two of them can use their influence to craft a deal, to produce something that will mean Copenhagen is not regarded as a failure.

But there is a lot of work to do, a lot of ground to cover and not a lot of time.

"Crucial" was the word everyone was using at the beginning of Wednesday, but by the end it was "deadlock".

And everyone is hoping they are still not using the same word when Friday comes around.