Image caption Crises such as that in Somalia could be far worse as a result of climate change, Mr Steiner says

Climate change poses a major threat to future peace and security, a senior UN official has warned.

Achim Steiner from the UN Environment Programme said climate change would also "exponentially" increase the scale of natural disasters.

His comments followed a UN declaration of famine in parts of Somalia.

Meanwhile, Russia rejected a Security Council statement backed by Western nations which asserted the link, but later agreed to a weaker text.

The Russian envoy Alexander Pankin said he was sceptical about the implications of putting climate change on the security council's agenda.

Security Council members finally agreed to a text which spoke of the "possible security implications" of climate change.

'Exponential growth'

Mr Steiner warned that an increase in the frequency of natural disasters across the globe could prove a major challenge in the coming decades.

He said recent crises, such as in Somalia, illustrate that "our capacity to handle these kinds of events is proving a challenge, particularly if they occur simultaneously and start affecting, for instance, global food markets, regional food security issues, displacing people, creating refugees across borders".

This is a good day today for climate security Peter Wittig, German Ambassador

"Clearly the international community - if the scenarios in climate change for the future come true - will face an exponential growth of these kinds of extreme events," he added.

His comments came as the Security Council formally debated the environment for the first time in four years, with Germany pressing for the first-ever council statement linking climate change to global peace and security.

Diplomats said there were intense negotiations between Germany and Russia, which initially opposed any council action, before a statement on the issue was agreed to.

Speaking as negotiations were continuing, Mr Pankin argued that the move was unnecessary and opposed by many countries.

"We believe that involving the Security Council in a regular review of the issue of climate change will not bring any added value whatsoever and will merely lead to further increased politicisation of this issue and increased disagreements between countries," he said.

However US Ambassador Susan Rice said that the council had an "essential responsibility to address the clear-cut peace and security implications of a changing climate" and said all countries should be demanding action.

She also called failed attempts to reach consensus earlier in the day "pathetic" and "shortsighted".

Somalia famine

The final statement expressed "concern that possible adverse effects of climate change may, in the long run, aggravate certain existing threats to international peace and security".

It also requested UN Secretary-General Ban Ki-moon to include information on possible climate change impacts in his regular reports on global trouble-spots.

German Ambassador Peter Wittig welcomed the outcome, describing it as a "good day today for climate security".

"We had quite extensive discussions," Mr Wittig said. "We wanted to get everyone on board. And we did."

The council had failed to agree on whether climate change was an issue of world peace in 2007, when Britain brought up the issue.

The move came after two regions of Somalia were declared a famine, after the worst drought in six decades.

Conditions for famine include more than 30% of children being acutely malnourished, and four children out of every 10,000 dying daily.

More than 10 million people have been affected by the crisis across east Africa.