Bill Gates explains why he's giving away virtually all of his wealth by 2045 in "CBS Mornings" interview

Bill Gates wants to share all of his good fortune — literally. 

The billionaire businessman and philanthropist revealed exclusively to "CBS Mornings" on Thursday that he will give away virtually all of his wealth over the next 20 years through the Gates Foundation. He says a total of $200 billion will go toward causes that will help save and improve lives around the world. 

"By deciding to spend all this money in the next 20 years, we can get a lot more done," Gates said in an interview taped last week, days before he announced the initiative. He's confident the money will save "tens of millions of lives."