By Paul Reynolds
World Affairs correspondent BBC News website
Demonstrators have taken to the streets in advance of the debate
The Security Council has held its first ever debate on climate change.
The debate was initiated by Britain, which holds this month's council presidency, with the argument that climate change could pose to world security.
It is an attempt to build up the debate from its scientific foundations and is being compared by British officials to a Security Council discussion in January 2000 on the threat to security in Africa of HIV/Aids. That debate is reckoned to have been what one British official called a "turning point" in getting international action on the disease.
Whether this debate will make a significant impact on climate change remains to be seen.
The British Foreign Secretary Margaret Beckett chaired the debate and said: "The Security Council is the forum to discuss issues that
threaten the peace and security of the international
community. What makes wars start? Fights over water.
Changing patterns of rainfall. Fights over food production,
land use...There are few greater potential
threats to our economies too...but also to peace and
However there were objections from developing countries who said that the Security Council was infringing on the roles of other UN bodies.
Russia did not veto the debate, as it could have, but was not enthusiastic and the United States chose to stress the role that governments should play.
"The most effective way to bolster security and stability
is to increase the capacity of states to govern
effectively, " said the US UN ambassador Alejandro Wolff.
And China all but dismissed the discussion, calling it "an exception" and stating that the Council was "not the right decision-making place".
But the UN Secretary General Ban Ki-moon supported the debate. He said there were some "alarming scenarios" that could weaken the power of states to resolve conflicts.
The key British official in this effort is John Ashton, who was appointed special climate change representative by Mrs Beckett when she took office almost a year ago. Since then, the Foreign Office has had to get used to dealing with climate as a diplomatic issue.
Formerly in the Foreign Office himself, John Ashton is now on secondment from a climate lobby group called E3G.
"The security implications of climate changes are bigger than we thought even two or three years ago," he said of the Security Council debate.
"Their effects can already be seen in Darfur and in water shortages in Central Asia. The recent European summit committed the EU to a lower carbon economy and was a key moment. Now it is in the Security Council.
"The significance of the Security Council debate is the debate itself. The Council has not had one before. But if there is no action, there will be no winners. All will be losers."
Role for China
John Ashton has previously stressed the importance of international action, saying in particular that without action by China on its coal-fired power stations, the efforts of many other nations will be in vain.
"If you do not have a policy for coal, you do not have a policy for climate," he stated.
As for the United States, British officials say there has already been a "very dramatic shift towards a more engaged position" and that a growing number of individual US states are taking action in the absence of a federal government lead.
"But this is not only about government decisions," one senior official said.
"It is about changing where investment goes. International agreements are simply the means to the end of shifting investment to low-carbon economies. It is not a war but it does require worldwide mobilisation."
The British mission to the UN circulated a paper explaining why it felt that a discussion was needed.
For a Foreign Office document, it is full of unusually stark phrases. It shows the new diplomacy of global warming at work.
It warns of "major changes to the world's physical landmass during this century", resulting in border and maritime disputes.
"Areas of concern include the possible submergence of entire small island states [and] dramatically receding coastlines," it says.
Two-hundred-million people could be displaced by the middle of the century because "substantial parts of the world risk being left uninhabitable by rising sea levels".
There could be conflicts over "scarce energy resources, security of supply and the role energy resources play once conflict has broken out".
A day in advance of the Security Council discussion, a report is being published by a significant new player in the climate change debate - the United States military.
A report, issued from the federally-funded Center for Naval Analyses and written by 11 senior retired generals, says that global warming "presents significant national security challenges to the United States".
It says that climate change "can act as a threat multiplier for instability in some of the most volatile regions of the world".
Last month, the US Army War College and the Triangle Institute for Security Studies held a seminar entitled "The National Security Implications of Global Climate Change."
The seminar invitation stated: "This is an important and timely topic, deserving serious analysis and discussion."