Efforts to come to grips with climate change are among the national priorities President Barack Obama has had difficulty advancing, even though he's five months into his second term. Now, Obama says he wants to change that.

President Obama in video previewing climate change address (YouTube)

In an online video released by the White House, Obama says that in a speech Tuesday he will lay out his vision for reducing carbon pollution. The aim is to prepare the U.S. for the effects of climate change and lead other nations in the global effort. Obama's speech Tuesday afternoon at Georgetown University will come the day before he leaves for a weeklong trip to three African nations.

In the video, Obama says, "There's no single step that can reverse the effects of climate change." But he adds that "when it comes to the world we leave our children, we owe it to them to do what we can."

He says scientists must design new fuels and energy sources, and workers must prepare for a clean energy economy.

(Copyright 2013 The Associated Press. All Rights Reserved)