Bob’s blog: Shooting at Fort Hood; U.N. Releases dire report on climate change

(CBS News) -- This Sunday on Face the Nation, the shooting on Wednesday at Ford Hood Military base will lead off our broadcast. The killing, which took the lives of three people and wounded 16, is the second to occur at this site. In 2009, a gunman there killed 13 people. We'll talk to House Homeland Security Committee Chairman Michael McCaul (R-Tex.) on what authorities have learned about a possible motive in these shootings, and what can be done to prevent tragedies like this in the future. Will the incident will spur increased security at military bases? We'll see what McCaul has to say about that, and whether he thinks this tragedy could ramp up the pressure on lawmakers to pass gun control legislation, which failed to pass Congress last year.

Later on, we'll speak to Thomas Friedman of The New York Times and Heidi Cullen of Climate Central about the U.N. report released this week that predicts dire environmental consequences if global greenhouse gas emissions are not reduced. Friedman is a correspondent in the new Showtime documentary series "Years of Living Dangerously," which takes viewers around the world to look at the fallout from climate change.

White House Senior Adviser Dan Pfeiffer will also join us to discuss the Obama administration's announcement this week that 7.1 million Americans had enrolled in health care plans from exchanges provided by the Affordable Care Act.

And just days before four Presidents (Carter, Clinton, George W. Bush and Barack Obama) travel to the LBJ Library in Austin to honor the 50th anniversary of the Civil Rights Act, we'll talk to Politico's Todd Purdum, whose new book, AN IDEA WHOSE TIME HAS COME, details the behind the scenes battle waged by LBJ for passing the law back in 1964. CBS News Political Director John Dickerson and Amy Walter of the Cook Political Report will also join us on our panel.

We hope you'll join us this Sunday.