Europe defended its record Wednesday in curbing Earth-warming greenhouse gas emissions as the countries of the world entered their third day of talks in Qatar on ways to tackle climate change.

Under pressure at UN negotiations in Doha to raise its emissions reduction target from 20 to 30 percent, the European Union said through its climate commissioner that other countries should also do more.

"Europe is doing its fair share," Connie Hedegaard insisted at a webcast press conference in Brussels.

The bloc is on track to meet its goal of emissions reductions of 20 percent by 2020 compared to 1990 levels and is poised to exceed it, thanks to support for greener fuels and cleaner technology, she said.

"We are not just resting on the laurels. We are actually trying despite all our economic difficulties to move on and still be in the lead, which we are," Hedegaard said.

The latest round of UN climate talks opened in Doha on Monday with developing countries and the EU staking out rival positions on the fate of the Kyoto Protocol, which binds rich nations to greenhouse gas emission caps.

Small island states most exposed to rising sea levels want the EU as a historical polluter to boost its emissions-slashing targets and bring forward the deadline for meeting them.

Hedegaard agreed that the world faced a "huge challenge" in the growing gap between targets and the actual emission levels required to hold climate change at a manageable two degrees Celsius (3.6 degrees Fahrenheit) from pre-industrial levels.

UN climate chief Christiana Figueres reminded delegates at the Doha talks of the urgent need to cut emissions even further.

"International commitments to cut greenhouse gases and deal with the impacts of climate change are higher than they have ever been, yet are still not sufficient to prevent the global average temperature rising beyond the two degrees Celsius target," she said in a statement.

Hedegaard said the EU had convinced the conference presidency to call a five-hour ministerial meeting next week to discuss options to help boost short-term emission reduction targets, such as phasing out fossil-fuel subsidies.

Climate observers meanwhile urged the rich world to provide details on how it intended to boost funding for poor nation's greenhouse gas reduction efforts from $30 billion in the period 2010-2012 to $100 billion a year from 2020, as promised.

Failure to put a plan on the table by next week "could see this (conference) start to unravel," Tim Gore of Oxfam International said in a statement.

But Hedegaard said the details would probably not be finalised in Doha.

"We know that we have to come up with more money," said the commissioner.

"People are trying despite difficulties in their countries to come up with the money."