Today on "World News with Charles Gibson":

China Quake:
The death toll from Monday's massive magnitude-7.9 earthquake in China has passed 12,000, and the number is expected to continue to rise as thousands remain buried in the debris. While rescue workers search for victims, tens of thousands of survivors grieve with no place to go. ABC's team of reporters will have the latest on China's most devastating earthquake in three decades.

Power of Two:
How could doing two simple things today help you save the environment tomorrow? In the second installment of our series, "Power of Two," ABC's Dan Harris reveals two very simple ways that you can fight climate change.

And on our "World News" webcast along with our top headlines:":

Campaign Signs:
The webcast sits down with typography expert Brian Collins, who reveals what's behind presidential campaign signs. What do these posters mean, and how much do they matter for the race to the White House?