Christy Moore's recording of HOW LONG is on his album "This Is the Day," Columbia LP #503255.2, 2001.

According to Allmusic.com, "Jackson Browe" (sic) wrote it. I assume that's a typo for "Jackson Browne."

Indeed, Jackson Browne wrote and recorded a song called HOW LONG. It is on his album "World in Motion," Elektra LP 50, 1989.

The lyrics have been posted in this thread: Every 3 seconds...a child dies...Live 8.