Climate change is the defining challenge of our age and the eyes of the world are upon the delegates gathered for the climate change conference here, UN Secretary General Ban Ki-moon said on Wednesday at the opening of the high-level segment of the summit.
"The time for equivocation is over and the time to act is now," he said. "We now know that unless we act there will be severe consequences (of global warming) - sea level rise, droughts, floods and the loss of one-third of the world's animal species. The cost of inaction is far more than the cost of action."
As power suits took over from batik at the opening of the high-level segment and security reached an all-time high, the longest applause at the plenary hall of the Bali International Convention Centre was reserved for Australia's Prime Minister Kevin Rudd, who has ratified the 1997 Kyoto Protocol, his first act after he took office 10 days ago.
From the tone of remarks by the UN secretary general and other senior officials, it was clear that the delegates had not yet been able to agree on the Bali roadmap to start negotiations for a post-2012 treaty when the current phase of the Kyoto Protocol comes to end.
Reminding the delegates that climate change also provided an opportunity to move to a new age of green economics and sustainable development, Ban told them: "You must make this change possible.
"The consensus on the building blocks to address climate change must involve all nations - developed and developing. The atmosphere cannot distinguish between them.
"Climate change affects all but not equally. The poorest are hit hardest. Developed countries must continue to curb their greenhouse gas emissions. Developing countries need incentives to move in the same direction."
The UN secretary general told the assembled delegates: "What the world expects is for you to start negotiations. I know agreement will not be easy. The UN will assist in every possible way.
"You have a clear charge. This is your chance to live up to it. If we leave Bali without a breakthrough we'll fail the people of the world and future generations.
"We're all part of the problem. Let us all be part of the solution."