Copenhagen 'high level agreement' possible: Key

"I think you are seeing some political momentum building and that's positive," he said at his post-cabinet press conference.

"But ultimately you will not see a binding agreement concluded in December. That would require much better work in 2010."

The United Nations conference began today, with the leaders' meeting due on December 17 and 18.

Initially, Mr Key had not planned to attend because the conference was not expected to reach any firm conclusions on a binding international agreement.

Earlier today Mr Key, speaking on TVNZ's Breakfast programme, said while he had originally intended to skip the meeting he changed his mind after his recent trip to the Commonwealth Heads of Government (Chogm) meeting.

"When I went off to Trinidad and Tobago a number of leaders said to me 'look we think it's important that New Zealand's there, partly to show solidarity, but also to make sure we get a balanced approach there. I think you've got to be in the room'," he said.

Not attending could give the wrong impression, he said, "... and also it's important to make sure that if we do sign up to something, even though I don't think it will be binding in December, but it well may might be next year, I think it is important that I am there and I can at least put our case if we need to."

The possibility of some "face time" with the president has boosted Mr Key's claim that Copenhagen has become too important a networking opportunity to miss.

The United Nations conference this and next week faces the very difficult task of agreeing on the outlines of a new pact to replace the existing Kyoto Protocol to reduce emissions blamed for upsetting earth's climate system.

But the two-year process leading up to Copenhagen has yielded little progress, with divisions between rich nations and poor ones, and friction between advanced economies over burden-sharing.

LEADERS SIGN UP FOR SUMMIT

Originally the summit was for ministers rather than leaders, but Danish prime minister Lars Lokke Rasmussen has pushed for leaders of countries attending the summit to be there in person with many, including United States President Barack Obama, now attending.

As many as 100 world leaders are now expected to join tens of thousands of environmentalists, media and protesters in gathering for the summit, which is being touted in some quarters as the most important since World War II.

The White House announced during the weekend that President Obama was shifting the timing of his visit so he could attend the leaders' meeting on December 17 and 18.

He had originally planned to attend earlier sessions of the talks, but was now hoping to capitalise on steps by India and China to put forward specific proposals for cutting carbon emissions and financing efforts by developing countries.

Mr Key will now attend the leaders' meeting with Mr Obama.

"The Danish Prime Minister, who is hosting the event, needed to get some momentum to get it back on the rails, so they organised the leaders' event," Mr Key said.

Mr Key said New Zealand has difficult issues regarding climate change including that per capita it was facing faster population growth than other developed countries, that it already was a big user of renewable energy so there was less room to expand on that and that half the country's emissions were from agriculture; "we have no answer to methane and nitrate emissions and in the same breath we are trying to feed the world".

He leaves for Denmark next Tuesday.

Other leaders attending include Australian Prime Minister Kevin Rudd, British Prime Minister Gordon Brown and French President Nicolas Sarkozy.

Politicians and officials from 192 countries will attend the conference.

Fourteen New Zealand officials will start negotiations this week, led by climate change ambassador Adrian Macey, of the Foreign Affairs and Trade Ministry. They will be joined the following week by ministers Tim Groser and Nick Smith.

New Zealand says it will reduce emissions by between 10 and 20 per cent, but only if changes are made to carbon trading rules. For example, it wants changes to the "offset" rule, which penalises forest owners who cut down trees without replanting on the same land.

On Saturday, Oxfam organised a mass haka in Auckland to challenge world leaders to take action on climate change.

CLIMATE CHANGE ACCEPTED

Mr Key again confirmed that he accepted the science on climate change.

"I personally think human-induced climate change is happening," he said.

"I've also thought Kyoto was a bit of a hoax, and I've said that, and the Labour Party took that to be a proxy of climate change. I actually think Kyoto is not a well structured document."

Tackling The Environment

Lucy Lawless, actress: "There is no planet B. Let's go about the business of tackling climate change. Our Government needs to sign on to a 40 per cent reduction target by 2020."

Gerrit van der Lingen, New Zealand Climate Science Coalition: "I hope no agreement will be reached. After all, there is no scientific evidence human greenhouse gas emissions are causing dangerous global warming. Actually, the planet has been cooling for the last 10 years while CO2 levels kept on increasing. I call it the greatest scam in human history."

Joe Milne, 19, shoe salesman, Wadestown: "It's going to be a problem for my kids, and their kids. It's good that Key's going; you need the top figures there."

Angelica Vestin, 27, mother, Tawa: "Hopefully it will not just be talking, and it will lead to some real action. Climate change does have an effect on the Earth, and it's something that everyone can do something about."

- By PAUL EASTON, with NZPA

- © Fairfax NZ News