At the UN Climate Change Conference in Bali last year, Parties to the UNFCCC decided on both the time-line and the main elements of a stronger climate change deal, including a shared long-term vision and enhanced action on the four building blocs: mitigation, adaptation, technology and finance.

The Bangkok meeting is supposed to be technical-oriented and "boring", UN officials said.

A new Ad Hoc Working Group on Long-Term Cooperative Action (AWG- LCA) was mandated in Bali to lead the work and is meeting for the first time in Bangkok. Its main task is to spell out the next steps needed to come to the envisaged agreement.

"What we now need is a bottom-up approach on all the elements, taking all the concerns of the Parties into account," said Luiz Alberto Figueiredo Machado, chairman of the AW-LGA.

Equal time will be devoted to the discussions of four key building blocks – mitigation, adaptation, technologies and financing – in the Bangkok talks and negotiations later, said Machado.

The second working group that is meeting at Bangkok is the already existing Ad Hoc Working Group on further Commitments for Annex I Parties under the Kyoto Protocol (AWG-KP). This group of rich countries will work on the analysis of possible tools available to these countries to reach emission reduction commitments.

"There is already broad consensus among Parties on the importance of completing this work before political agreement is reached on a post-2012 deal in Copenhagen," said Harald Dovland, chair of the group.

The next UN meeting involving negotiations under both working groups will take place in June in Bonn, Germany this year, followed by a third meeting in August and a fourth at the UN Climate Change Conference in December, both to be held in Poznan, Poland.

The tools that the working group will analyze in Bangkok include emissions trading and the "project based mechanisms", such as Clean Development Mechanism (CDM), which already allows developed countries to meet part of their emission reduction commitments by investing in sustainable development projects in developing countries.

Other tools are land use, land-use change and forestry; greenhouse gases, sectors and source categories to be covered, along with possible approaches targeting sectoral emissions, for example from the steel or cement sectors.