Green Balloon Club was a live-action BBC television series produced in 2008 and originally shown on the CBeebies channel from 2008 until around the mid 2010's. The show is about 5 kids called Jay (Played by Jake Pratt), Cat (Played by Thai Murray-Edwards), Lilly-Rose (Played by Isabella Blake-Thomas), Ant (played by Adam Wells) and Sky (Played by Debbie Corley, but she later left the series and was replaced with Chris Packham from Springwatch and Autumnwatch) alongside a dog named Skipper who travel around in a Green hot-air Balloon exploring our world and about the nature.
None of the 48 episodes have surfaced onto YouTube after the series was taken off the air in the mid 2010's, but all the songs from the show have. A YouTube Pooper used footage from one of the episodes in a video called "YouTube Poop Does Something Green" but the video was taken down and the user was likely terminated.
A user by the name of Bubble Penguin had uploaded all 10 episodes of the "Green Balloon Club Goes on Holiday" Miniseries in Late February 2017, alongside all but 3 episodes of the spin-off series "Green Balloon Club Scrapbook" but they are in poor quality and the sound is out of sync. (UPDATE: The user got them from the Chinese site Youku, and he deleted them after a few days due to the sync problems.)
The website for the show still exists through the Internet Archive Wayback Machine, which features interactive features and has a game which features original footage of the Green Balloon Club members.
After the show finished, it's unknown where the cast members have been, and only 2 of them were known to do other work. Isabella Blake-Thomas (Played Lilly-Rose) went on to voice a character in the animated show Jelly Jamm and Jake Pratt (Played Jay) went on to star in Billy Elliot: The Musical playing Billy Elliot's friend Michael.
UPDATE, 1ST MARCH 2017: The user Mayday51 sent a link to this BBC website: http://www.bbc.co.uk/programmes/b00chmr0/clips which has various clips from the series.
UPDATE, 30TH MAY 2017: CBeebies Australia still airs the show, but very early in the morning.
UPDATE, 24TH MAY 2018: 4 full episodes have been uploaded to YouTube.