Why isn't cremation in this guidebook?

Fifty years after Jessica Mitford published The American Way of Death cremation has overtaken burial as America's preferred choice for disposing of a body. So why isn't there a cremation line in the The Natural Burial Cemetery Guidebook?

Many of the cemeteries listed do bury cremated remains in their green burial sections or have separate sections. I don't happen to believe that cremation is green. Why?

1) Fossil fuels It takes 2 to 3 hours at extremely high heat to cremate a human body, and so far only non-renewable fossil fuels are up to the job of creating that environment.

2) Pollution Burning a body releases mercury and other toxic metals into the atmosphere, along with CO2.

3) Cremation burns everything into gas or ash. Green burial is about recycling a human body back into the earth, releasing its nutrients to be used by other life.

4) "What if I'm concerned about land use for burial? I take up less room if my ashes are buried in a biodegradable urn, even turned into a tree, right?" Actually unprocessed ashes are toxic, and render soil sterile when buried in concentrations. Those urns that create trees only sample your ashes. 

5) "I like simplicity." You can't seriously tell me a state-of-the-art crematory is a simple machine. Think of the pollution controls on your automobile.

I believe in the power of green burial to change how we do and view death. It's as simple as being buried in a shroud or pine box.