The nation's new top mine-safety regulator plans to move quickly on a plan to lower miners' exposure to unhealthy dust that can cause crippling black-lung disease.

Dear EarthTalk®: It has been said that global warming will bring a new ice age. Is this true or only fiction?

President Barack Obama, with China's leader at his side, lifted his sights Tuesday for a broad interim accord at next month's climate conference that he said will lead to immediate action and "rally the world" toward a solution on global warming.