It’s never too late to join Facebook. President Obama unveiled his very own page on the social media site. His first post is a two-minute video showing the President walking through his White House backyard. In it, he urges Americans to protect the planet for future generations. Mr. Obama’s climate change message implores viewers to “Preserve this beautiful planet of ours.” He says now’s the time to join Facebook, with nearly three in four adults active on it. Aside from the official White House page, there is another ‘Barack Obama’ Facebook account. It is run by his community action advocacy group.The President has been more active on social media nearing the end of his second term. He joined Twitter in May.