The opening ceremony was stirring but the prospects for progress are stark.
A new round of UN climate talks has begun in Mexico with almost 200 nations trying to agree on modest steps to slow global warming.
After no breakthrough in Copenhagen last year, the two-week conference at the beach resort of Cancun seeks to get negotiations back on track.
The talks, at a tightly-guarded compound, aim to agree a tougher climate deal to succeed the Kyoto Protocol, whose present round ends in 2012.
On the sidelines of the summit, Oxfam threw a bottle out to sea with a message to delegates reading: “Urgent: Save Lives in Cancun.”