The climate change meeting in Bonn, Germany, is the second in a month. It is aiming to advance a universal climate agreement by 2015, which will come into force from 2020, and to find ways to increase the inadequate level of global ambition to address human-generated climate change before the end of the decade.

This includes kicking off an in-depth review of the adequacy of the universally agreed 2C temperature increase target, described as a reality check on the advance of the climate change threat and the possible need to mobilize further action.

A session on Saturday will also be dedicated to empowering so-called "non-state actors", including business, to address climate change. The business sessions were the most concrete at the disappointing multinational talks in Doha, Qatar last year.

“The negotiations are now in a crucial conceptual phase of the 2015 agreement, and need inputs from all relevant stakeholders,” said UNFCCC executive secretary Christiana Figueres.

"With growing numbers of countries enacting climate legislation, with investment in renewables growing and private sector attention to climate risk increasing, the negotiations can capture the energy and dynamism of all stakeholders, who in turn need to provide clear inputs as to where more ambition is possible, and where international policy guidance from governments can unleash even more action on their part."

There will be several workshops, including:

* the International Energy Agency will lay out important new insights into the future track of global greenhouse emissions in its latest World Energy Outlook Special Report, "Redrawing the energy-climate map";

* how to strengthen adaptation to climate change through the 2015 agreement; and

* on pre-2020 ambitions, focusing on how to scale up renewable energy, enhance energy efficiency and consider carbon capture and storage.

Other discussions include talks on institutional arrangements that provide the most vulnerable populations with better protection against loss and damage caused by slow onset events such as rising sea levels; on clarifying ways to measure deforestation; and on avoiding negative consequences of climate action.

The next annual UN Climate Change meeting is in Warsaw on November 11-22.