Do the World's Forests Really Help Prevent Global Warming?

At least some of the world’s forests are coming back, and Planet Earth may not become a "skinhead" after all. But will more trees help prevent global warming? We hear about new controversy over the role of forests in climate change and the multi-billion dollar business of carbon trading. Plus, Iraq prepares itself for political turmoil as it issues an arrest warrant for a leading Sunni cleric, and France may get its first woman president.