京都議定書於2006年2月16日生效，然議定書中規定的第一減量承諾階段卻很快的將在2012 年12 月31 日截止，必須要有新的減量目標來延續，才能達成公約減緩溫室氣體排放並避免全球暖化危害氣候系統的目標。本文以國際法與國際氣候變遷法的觀點觀察目前在遵約以及新減量目標談判的現象，檢討這些現象是否符合公約的規範目的，以及現在各類爭議發展的趨勢與現狀，作為判斷達成新減量目標的法律上依據。就目前所收集的資料觀察，今年在墨西哥召開的第十六屆締約國大會要有一具體或有共識作為討論第二減量期間之目標，是一個非常艱鉅的挑戰。

The Kyoto Protocol entered into effect on 16 February 2006 but the first
reduction commitment period will be ended on 31 December 2012 very soon. The Parties shall reach another decision and make a new reduction during the 2013 to 2018 to extend the efforts on reducing the global greenhouse
gas emission. It could also comply the objectives of the Convention on
stabilizing the anthropogenic emissions of greenhouse gas in the atmosphere on a level for not endangering the climate system. This article reviewed the new reduction targets proposed by the Parties during the international negotiations from international law perspective, and analysis whether those proposals are complying the objective of the Convention and fulfill the requirements of the climate change laws. Based on the reviewing on the collected data and documents, to reach new commitments for second commitment period on the 17th Session on Cancun, Mexico is almost impossible.