Poor countries should be given extra help to avoid the worsening effects of climate change, a UN conference on global warming has been told.
Campaigners say millions of lives are at risk from climate change
Argentina's environment minister Ginés Gonzalez Garcia opened the conference in Buenos Aires by saying his country had already experienced major changes.
High rainfall, violent storms and increased levels of disease were all blamed on climate change, he said.
The meeting takes place a month after Russia ratified the Kyoto Protocol.
Delegates to the conference, the 10th annual UN session on climate change, are expected to debate the need for extra measures above and beyond the Kyoto agreement.
The protocol, which will become a legally binding treaty in February, requires signatories to lower emissions of greenhouse gases to 1990 levels by 2012.
But the US, the world's biggest economy and largest emitter, has refused to sign.
Getting on track
Because developing countries, including rapidly growing economies such as China and India, are not required to make cuts, the protocol only applies to around 30% of the world's greenhouse gas emissions.
Even so, the executive secretary of the UN Framework Convention on Climate Change, Joke Waller-Hunter, said the Buenos Aires meeting was taking place in a very positive atmosphere.
She told the BBC News website: "I feel pretty upbeat, because we have the political momentum back in the process, due to the fact that the Kyoto Protocol will now enter into force on the 16th of February.
"I think that will make a huge difference to the mood in which this meeting takes place."
Ms Waller-Hunter accepted that most industrialised countries which signed up to the agreement were still a long way from achieving their agreed emission cuts averaging 5.2% between 1990 and 2012, but thought there was now a good prospect of those targets being met.
'Millions at risk'
It is Mr Garcia's view that developing nations should be offered material help to reduce the impact of climate change on their landscapes and slow the process.
Others are using the conference as an opportunity to put pressure on the US, as well as other major polluters including China and India, into working within the Kyoto accord.
The BBC's Elizabeth Blunt, who is in Buenos Aires, says the determination of delegates at the conference to act against climate change may offer an opening to the US.
US officials have claimed the Kyoto accord will unfairly affect American industry.
Around 6,000 people, including 150 government delegations and representatives of industry and environmental groups, have gathered in Buenos Aires for the conference.
Environmental campaigners from Greenpeace built a large model of Noah's Ark in the centre of Buenos Aires in an effort to stress that urgent action needs to be taken to combat the effects of climate change.
They claim the ark, 30m long and 7m high, points to the immediate danger facing humans and animals in the face of climate change.
"We have a queue of people wearing lifejackets trying to get into the ark," Greenpeace campaigner Stephanie Tunmore told the BBC.
"It symbolises the danger of climate change and the risk that we are running by not doing anything about it, the millions of people that will lose their lives if we don't sort this problem out."