Nearly 200 nations gather in Doha from Monday for a new round of climate talks as a rush of reports warn extreme weather events like superstorm Sandy may become commonplace if mitigation efforts fail.

Negotiators will converge in the Qatari capital for two weeks under the UN banner to review commitments to cutting climate-altering greenhouse gas emissions.

Ramping up the pressure, expert reports warned in recent days that existing mitigation pledges are not nearly enough to limit warming to a manageable 2 degrees Celsius (3.6 deg Fahrenheit) from pre-industrial levels.

"A faster response to climate change is necessary and possible," UN climate chief Christiana Figueres said ahead of the talks.

"Doha must make sure the response is accelerated."

The UN Environmental Programme said this week the goal of keeping planet warming in check has moved further out of reach and the world was headed for an average 3-5 deg C temperature rise this century barring urgent action.

And the World Bank said a planet that is four degrees warmer would see coastal areas inundated and small islands washed away, food production slashed, species eradicated, more frequent heat waves and high-intensity cyclones, and diseases spread to new areas.

"Time is clearly not on our side," Marlene Moses, chairwoman of the Alliance of Small Island States told AFP.

Topping the agenda in Doha is the launch of a followup commitment period for the Kyoto Protocol, the world's only binding pact for curbing greenhouse gas emissions.

Delegates must also set out a work plan for arriving in the next 36 months at a new, global climate deal that must enter into force by 2020.

Negotiators will be under pressure to raise pre-2020 emission reduction targets, and rich nations to come up with funding for the developing world's mitigation actions.

The planet has witnessed record-breaking temperatures in the past decade and frequent natural disasters that some blame on climate change -- recently superstorm Sandy which ravaged Haiti and the US east coast.

Yet countries disagree on several issues, including the duration of a "second commitment period" for the Kyoto Protocol, which binds about 40 rich nations and the EU to an average five percent greenhouse gas reduction from 1990-levels.

That commitment runs out on December 31.

The EU, Australia and some small Kyoto parties have said they would take on commitments in a followup period, but New Zealand, Canada, Japan and Russia will not.

Small island countries under the most imminent threat of warming-induced sea level rises, demand a five-year followup period, believing this will better reflect the urgency.

The EU and others want an eight-year period flowing over into the 2020 deal.

Poor countries also want rich states to raise their pledges to curb warming gases, including the EU from 20 from 30 percent.

"The biggest historical emitters have a responsibility to do more, much more, than they have to date," said Moses.

The developed world has already agreed to boost funding for the developing world's climate plans to a level of $100 billion a year from 2020 -- up from a total $30 billion over the period 2010-2012.

But no numbers have been decided for the interim, nor is it clear where the new money will come from.

"If no agreement is achieved in Doha, we will enter 2013... with no support to help many developing coutries in reducing their emissions," said Wael Hmaidan, director of the NGO Climate Action Network.f

Delegates will be joined by more than 100 government ministers for the final four days of talks, notorious for dragging out way past their programmed close as negotiators hold out to the last in a poker-like standoff.

"Doha... will send important signals about whether the world can still manage to keep warming within tolerable limits, or if we are headed for severe climate chaos," said Kelly Rigg, executive director of the Global Campaign for Climate Actions.