Though the UN climate talks in Durban enters final hours of negotiation, no breakthrough in extending the Kyoto Protocol is in sight. That's unless the world's major developed nations muster enough political will and courage to shoulder its due responsibility to combat climate change.

U.S. President Barack Obama conceded the United States has been unable to send a low carbon emissions plan through Congress when he visited Australia in November.

In practice, climate diplomacy is thus facing a similar challenge to the one during the eight years of George W. Bush's presidency. That was after Bush had withdrawn the U.S. from the Kyoto Protocol, the first and only international agreement on the stabilization of greenhouse gas concentrations in the atmosphere.

After nearly two weeks of stalled progress at climate conference in South Africa, the Least Developed Countries, the Alliance of Small Island States and the European Union said a few hours before the end of the conference that they are united in their desire for an ambitious outcome.

Studies from the International Energy Agency, the United Nations Environment Programme, and countless other peer-reviewed scientific papers show that waiting until 2020 to begin aggressive emissions reduction would cause irreversible climate change, including heightened tropical storms, worsening droughts, and devastation affecting communities and businesses from Africa to America.

Nevertheless, the U.S. has held strong to its woefully inadequate and voluntary commitments made in the Copenhagen Accord and Cancun Agreement. Meanwhile, some developed countries, historically responsible for a majority of the world's greenhouse gas emissions are not taking bold steps.

During the Durban talks, Washington reiterated that it will not agree to any legally binding agreement, unless that agreement involves all major emitters.

In contrast with some developed countries' reluctance to demonstrate concrete action, many developing countries have been taking ambitious mitigation steps even though they have no mandatory caps.

China has declared at the conference that it could agree post-2020 binding commitments under certain conditions, a step that shows China's strong will to play a flexible and constructive role in pushing for positive outcomes of the conference.

According to a white paper China issued last month, the largest developing country has cut the amount of carbon produced per unit of economic output by 19.1 percent from that of 2005 accumulatively, equivalent to a reduction of 1.46 billion tons of carbon emissions.

With tens of millions of people living in poverty and more people living with low incomes, China has emitted 10 percent less pollution than in the previous five years beginning in 2006.

As the nations are racking their brains to reach an agreement on emission cuts at the global climate talks, the U.S. government decided Friday to continue anti-dumping and countervailing probes on China's solar panels, a protectionist step that could pull back the global green agenda by artificially charging green efforts with higher costs amid the world's economic woes.

The Durban gathering is a significant moment for collective responsibilities and it's time for the U.S. and other developed countries to get back in the game instead of being restrained by obstructionism and divisive politics at home.

In the face of global climate change, there is no excuse for any inaction. Otherwise, it will be regrettable to miss such an opportunity at the Durban talks to address the growing threat.