Google+ is not long for this world, but it will live on with the help of the Internet Archive. A project is already underway to save all public Google+ pages to the archive, ensuring that the content won't vanish on April 2nd when Google pulls the plug. If your profile is open, it may already be safe and sound.
Google announced the shutdown of Google+ later last year, citing extremely low usage and a newly discovered bug that exposed personal data. Initially, it wanted to kill the consumer-facing site this coming summer, but in December Google accelerated the timeline. At that point, the Archive Team sprung into action. The Archive Team is a network of volunteers who download endangered data for the Internet Archive, and you can follow its Google+ progress in real time.
The internet has made is much easier to disseminate information, but it's also made information more "disposable." Websites and services go offline all the time, taking content with them. The Internet Archive exists to make sure that data doesn't disappear.
As of this posting, the Archive Team has downloaded more than 360 terabytes of data from Google+. It will all go up on the Internet Archive, accessible to the public using the Wayback Machine. If you have a lot of local storage and bandwidth, you can help the Archive Team by running a "Warrior" virtual machine to download Google+ data. If for some reason you don't want your public Google+ content mirrored, you can request a removal, too.