Don't leave out cow farts and belches. These people need a job directing the turtle traffic in California to the tunnels under their roadways. Problem with hugging trees is it has a tendency to cut off the circulation to the brain. Frankly I like spotted owls, they taste similar to chicken. Save a tree, wipe with an owl.
The assumed 1.5% leakage rate strikes me as too high. You might want to pose the question to OakesCS, who has professional experience in these matters. Regards, Dew