After the opening warning shots of “agree a deal to save the planet or else”, comes the hard talking.
Organisers in Copenhagen of the biggest climate change conference in history told diplomats from 192 nations that now is the time to put flesh onto the bones of promises.
At stake is a deal that aims to wean the world from fossil fuels to greener sources of energy and to transfer hundreds of billions of euros from rich to poor countries to help them adapt to climate change.
Those in the conference hall were left in no doubt by a 24-year-old from Fiji, as to the importance to countries likely to be washed away by rising sea levels as the world heats up.
Leah Wickham broke down when she urged delegates to agree a climate change deal.
“We need a deal that is fair to the poorest people and nations that have had little or nothing to do with the issue, but that will be affected the most,” she said.