The United Nations climate change chief Monday called on governments to quickly transform the agreements reached in the Mexican city of Cancún last year into tangible action on the ground, and provide clarity on the future of the Kyoto Protocol on greenhouse gases emissions.

"Governments must now implement quickly what they agreed in Cancún and take the next big climate step this year in Durban," the Executive Secretary of the UN Framework Convention on Climate Change (UNFCCC), Christiana Figueres, told reporters in Tokyo.

The UNFCCC is an international treaty which considers what can be done to reduce global warming and to cope with whatever temperature increases are inevitable. Some countries have approved the Kyoto Protocol, an addition to the treaty, which has more powerful and legally binding measures.

Ms. Figueres is currently in Japan to meet with government officials, Japanese business and other civil society representatives, and to attend informal talks on Thursday, jointly organized by the governments of Japan and Brazil.

The agreements reached in Cancun, at the 16th Conference of the Parties to the UNFCCC in December last year, included formalizing climate change mitigation pledges and ensuring increased accountability for them, as well as taking concrete action to tackle deforestation, which accounts for nearly one-fifth of global carbon emissions.

Ms. Figueres described the outcome of the Cancún meeting as a solid step forward for strengthened global climate action, encompassing the basis for the largest collective effort the world has ever seen to reduce greenhouse gas emissions.

In addition, she said, the Cancún Agreements formed the most comprehensive package ever decided by governments to help developing countries deal with climate change, and a long-term global agreement to keep average global temperatures below two degrees Celsius compared to pre-industrial levels.

Ms. Figueres, however, warned that promises to reduce or limit emissions so far amounts to only 60 per cent of what the scientific community says is required by 2020 for global temperatures to remain below two degrees, and that emissions need to peak by 2015 to avoid the agreed temperature goal slipping out of reach.

Looking ahead to the next round of talks under the UNFCCC – to be held in Durban, South Africa, later this year – Ms. Figueres said governments need to agree on a way to cut global emissions about twice as fast as they have already promised, along with increasing the certainty that they will do what they say.

"Governments meeting in Durban must resolve the remaining issues over the future of the Kyoto Protocol," she said. "In this context, we need to keep in mind that the Kyoto Protocol remains the only working, binding international model to reduce emissions, and nations have an urgent task to decide how to take forward the protocol's unique benefits of transparency, certainty, compliance in handling national emission targets, and common but differentiated responsibilities."