Pete published a pretty comprehensive list of the songs he had added to in his book "Rise Up Singing." This is not there, so my best guess is that it's someone else. I would also suggest that Pete usually added a more political angle to his verses, and the lovely simplicity of the two verses don't reflect this. If it had not already been attributed elsewhere, I might have thought the "The Earth is the Lord's..." verse above might be Pete, for example.