Delegates at the UN climate summit in Durban, South Africa surprised many when they reached an agreement over the weekend that sets the stage for emission targets and a global fund for climate change adaptation. There's much to report on: the progress made, the challenges that remain, and the implications for global action on climate change.

But CNN has yet to report on the agreement during any of its U.S. television broadcasts.

Meanwhile, the Durban conference has been covered by NBC, CBS, MSNBC and even Fox News -- although much of Fox's coverage has been deeply flawed.

And apparently the story is considered newsworthy by CNN International, which has devoted 6 segments to the UN summit since it began on November 28, and has mentioned it on several other occasions, according to a Nexis search. CNN International airs in over 200 countries and territories around the world.

This disparity in CNN's climate coverage reflects a worrisome trend. Far too often, the major American news outlets are silent on climate change stories, while the conservative media -- led by Fox News - continuously and loudly cast doubt on climate science and perpetuate myths about any and all efforts to curb greenhouse gas emissions.

So it comes as no surprise that Americans are largely uninformed about the scientific consensus around human-induced climate change or about the projected impacts on the United States and elsewhere.

Climate change is one of the most significant challenges facing the human race, and the question of whether we will plan ahead to decrease our vulnerabilities hinges substantially on international cooperation. Apparently CNN's American viewers have to change the channel to stay informed on this important story.