Opening the High Level Segment of the Dec 7-18 summit where around 120 heads of state and government are scheduled to attend, Ban welcomed the Copenhagen Launch Fund by which rich countries will pay $10 billion a year for the next three years to help poor nations cope with climate change effects.
"But this fast start finance is just that, a start," the UN chief warned. "It won’t solve all our problems. We must address medium- and long-term financing needs."
Calling the UN Framework Convention on Climate Change (UNFCCC) conference a "defining moment in history", Ban said: "We’re here to write a different future. Climate change has risen to top of the international agenda. We know what we must do, we know what the world expects. Our job now is to seal a deal in our common interest."
The UN chief has been saying for a long time that climate change "is the defining challenge of our era". Here he added: "No issue is more fundamental to the global challenges we face."
Referring to climate change effects - melting ice caps, advancing deserts, rising sea levels - Ban said: "We have a real chance to change the course of our history. The momentum is there for a fair, ambitious and comprehensive deal. We must keep global temperature rise within two degrees" celsius.
That, the UN chief reminded delegates from 192 countries, required more ambitious (greenhouse gas emission) mitigation targets by industrialized countries, more action by developing countries, adaptation to climate change effects, financial and technical support by rich countries and a transparent structure to govern the money that would be given.
"We’ve come a long way. Let us not falter in the home stretch," he urged the delegates.Acknowledging that contrary to his original plan, there would be no legally binding treaty at this summit, Ban wanted the delegates to lay the foundation for one in 2010.
He said later at a press conference: "We must set a firm date to complete a new legally binding treaty in 2010 - this deadline cannot be left hanging."
Knowing about the bickering between developed and developing countries that has held the summit hostage, he said: "Every leader faces domestic pressures and domestic politics, but every citizen’s well-being is at stake if we don’t act now.Time for maximalist negotiating positions is over, time for consensus has arrived. No one will get everything they want, but if we work together, everyone will get what they need."
Ban gave a huge boost to the position of developing countries when he said the Kyoto Protocol - the current global treaty to tackle climate change - "must be maintained".
He told the delegates the current negotiations are "big as the negotiations that built the UN. Once again we’re at the cusp of history. Our future begins today, here in Copenhagen.
At the press conference that followed the opening session of the summit’s High Level Segment, Ban acknowledged there were "still many issues to be resolved. But I’m reasonably optimistic that Copenhagen will be a success, that we can have a deal that is fair, comprehensive and equitable."
He asked developing countries "to take greater measures to control growth of their emissions", not a statement designed to win him friends among them, but then immediately added that more money was needed for the proposed Copenhagen Growth Fund plus mid- and long-term finance.
Saying that he wanted a "politically binding agreement here", Ban added: "All countries can and must do more. Each leader must consider what more he can do to make Copenhagen a success."
He said current negotiations here were "too slow. I am asking the negotiators to expedite their work."
From the UN point of view, Ban said: "We pay most attention to Africa, small island states, least developed countries, landlocked countries and so on. That is why we are urging industrialized countries to do the maximum, while developing countries should undertake nationally appropriate mitigation actions."
At the opening session, Denmark’s Environment Minister Connie Hedegaard warned: “Success is still within reach, but we can fail. We must change gears and the keyword for the next two days must be compromise."