Here is some info from sirius.com, seems to be on several different channels...
"You can hear complete, commercial-free coverage of each Live Earth concert on SIRIUS beginning at 9 pm ET on July 6. Check out the locations below for details on artists and channels. SIRIUS also will broadcast “The Best of Live Earth” highlighting the most memorable moments on Super Shuffle channel 12 starting at 9 am ET on July 7.
Want to get a head start on the shows? Tune into Green 119: The SIRIUS Live Earth Channel starting July 4. Channel 119 will feature stories and interviews with SIRIUS personalities, environmental tips and myths, political commentary and more. You also can search by artist and get lineup information by calling the SIRUS Live Earth hotline at 877-33-SIRIUS; press “4” from the main menu.
SIRIUS will also exclusively broadcast the “Stop Global Warming Concert” on Friday, July 6 at 8 pm ET on The Spectrum channel 18. This concert, recorded Earth Day, April 22, 2007, features performances by Sheryl Crow and Carole King as well as a speech by the producer of An Inconvenient Truth.
Finally, Prime Country channel 61 will air a “Friends of Live Earth” performance live from Washington, DC on July 7. The event features performances by Garth Brooks and Trisha Yearwood along with a number of Native American acts. Al Gore kicks it off at 10:30 am ET."
Times and channels for each specific show can be found at sirius.com