As the 17th Conference of Parties to the UN Framework Convention on Climate Change started here Monday, disputes between developed and developing countries have grown fierce, despite the increasingly worsened climate challenge. As the first commitment period of the Kyoto Protocol, the world\'s sole legally binding international agreement to cut greenhouse gas emissions, expires in 2012, whether it should be extended became a focal point at the conference, also a battlefield of negotiators. Europe says it can accept a continuation of the Kyoto Protocol, provided China and the United States show they are serious about major cuts in the coming years. The United States, the world\'s largest polluter per capita, has said it would not sign up for an updated Kyoto Protocol. It wants the pact to impose obligations on emerging economies like China and India. Japan, Canada and Russia, three key countries in the Kyoto deal, have made it clear that they will not sign a second commitment period. The nearly irreconcilable differences leave the pact\'s future in doubt. On behalf of China, Brazil, South Africa and India, known as the four \"BASIC nations,\" Su Wei, deputy head of the Chinese delegation attending the COP 17, said: \"The Kyoto Protocol is the cornerstone of the climate regime and its second commitment period is the essential priority for the success of the Durban Conference.\" He called for an extension of the protocol. The question of who should take more responsibilities for the carbon emissions and do more to mitigate the impacts by climate change presented another topic of debate at the conference. South Africa\'s ruling African National Congress (ANC) on Monday urged developed countries to take bigger responsibility for measures to curtail climate change. ANC Secretary General Gwede Mantashe said developed economies accounted for most of the global emission of greenhouse gases while developing countries still had to contend with development needs and the need to reduce climate change caused by its citizens. In the meantime, the International Union for Conservation of Nature Monday said governments of various nations in the world play an important role in coping with climate change and that developed nations in particular need to shoulder more responsibility. Also on Monday, small island countries urge the international community to act quickly, or their countries would disappear in the future as a result of the rising sea level. Although the EU called for a deal to be reached by 2015 and implemented by 2020, the Alliance of Small Island States said the plan would do little to mitigate rising sea levels threatening their survival. But these quarrels are no answers to the common challenge faced by human beings, as the impacts of climate change have rapidly worsened in the recent years. The World Meteorological Organization (WMO), or the UN weather agency, said the amount of greenhouse gases hit a new high last year with an accelerated rate of growth. The WMO said the carbon dioxide level increased by 2.3 parts per million between 2009 and 2010, higher than the average for the past decade of 2.0 parts per million. Meanwhile, in a survey released Monday, which coincided with the Durban conference, the Food and Agriculture Organization said 25 percent of the world\'s land is \"highly degraded\" and 44 percent \"moderately degraded.\" \"Worldwide, the poorest have the least access to land and water and are locked in a poverty trap of small farms with poor-quality soils and high vulnerability to land degradation and climatic uncertainty.\" It stressed climate change, along with erosion and desertification, was the culprit that threatens major production systems across the world.