According to an e-mail circulated among the couple's friends and obtained by The Associated Press on Tuesday, the Gores said it was "a mutual and mutually supportive decision that we have made together following a process of long and careful consideration."
Gore spokeswoman Kalee Kreider confirmed the statement came from the Gores, but declined to comment further.
According to two long-time close associates and family friends, their decision came after a "long process of careful consideration."
The associates said the Gores, over time, had carved out separate lives, with the former vice president on the road frequently. One of the associates said: "Their lives had gotten more and more separated."Al Gore lost the 2000 presidential election to Republican George W. Bush. He has since campaigned worldwide to draw attention to climate change, which in 2007 led to a Nobel Peace Prize and an Oscar for the documentary "An Inconvenient Truth."
The Gores crafted an image as a happily married couple during his eight-year stint as vice president in the 1990s and a presidential candidate in 2000. The couple famously exchanged a long kiss during the 2000 Democratic presidential convention.
The image of their warm relationship stood in sharp contrast to the Clinton marriage rocked by Bill Clinton's affair with White House intern Monica Lewinsky, a scandal that hung over Gore's own presidential campaign.
Al Gore at the time said his wife was "someone I've loved with my whole heart since the night of my high school senior prom."
Tipper Gore was a co-founder in 1985 of the Parents Music Resource Center, which pushed for parental warning labels on music with violent or sexually explicit lyrics. The group drew the ire of musicians ranging from Dee Snider of Twisted Sister to Frank Zappa, who said warning labels were unnecessary and a danger to freedom.
Tipper Gore later became friends with the late Zappa's wife, Gail, and played drums and sang backup on daughter Diva Zappa's album in 1999.
The Gores have four adult children, Karenna, Kristin, Sarah and Albert III.